A preliminary understanding of the relationship between synthetic phenolic antioxidants and early pregnancy loss: Uncovering the potential molecular mechanisms

Mounting evidence suggests that environmental pollutants may affect reproductive health, potentially leading to adverse outcomes like pregnancy loss. However, it remains unclear whether exposure to synthetic phenolic antioxidants (SPAs) correlates with early pregnancy loss (EPL). This study explores SPA exposure's link to EPL and its potential molecular mechanisms. From 2021 to 2022, 265 early pregnant women (136 serum and 129 villus samples) with and without EPL were enrolled. We quantified 17 SPAs in serum and chorionic villus, with AO1010, AO3114, BHT, AO2246, and BHT-Q frequently being detected, suggesting their ability to cross the placental barrier. AO1135 showed a positive relationship with EPL in sera, indicating a significant monotonic dose-response relationship (p-trend <0.001). BHT-Q exhibited a similar relationship with EPL in villi. Inhibitory effects of BHT-Q on estradiol (E2) were observed. Molecular docking revealed SPA-protein interactions involved in E2 synthesis. SPA-induced EPL might occur with specific serum levels of AO1135 and certain villus levels of AO1010, BHT-Q, and AO2246. BHT-Q emerges as a potential biomarker for assessing EPL risk. This study provides insights into understanding of the exposure to SPAs and potential adverse outcomes in pregnant women.

Environmental copper exposure, placental cuproptosis, and miscarriage

Copper pollution has become global environmental concern. Widespread Cu pollution results in excessive Cu exposure in human. Epidemiological studies and animal experiments revealed that Cu exposure might have reproductive toxicity. Cuproptosis is a newly reported Cu-dependent and programmed cell death formTsvetkov et al., 2022. However, whether copper exposure at real environmental exposure dose might cause placental cuproptosis and induce miscarriage was completely unexplored. In this study, we found that Cu exposure during pregnancy induced miscarriage or complete pregnancy loss by inducing placenta cuproptosis in CuCl2-exposed pregnant mice. Notably, Cu exposure at 1.3 mg/kg/d (a real environmental exposure dose) was enough to cause placenta cuproptosis. CuCl2 exposure disrupts the TCA cycle, causes proteotoxic stress, increases Cu2+ ion import/decreases Cu2+ export, and results in the loss of Fe-S cluster proteins in mouse placenta, which induces placenta cuproptosis. Moreover, we also identified that Cu exposure down-regulates the expression levels of mmu-miR-3473b, which interacts with Dlst or Rtel1 mRNA and simultaneously positively regulates Dlst or Rtel1 expression, thereby disrupting the TCA cycle and resulting in the loss of Fe-S cluster proteins, and thus epigenetically regulates placental cuproptosis. Treatment with TTM (a cuproptosis inhibitor) suppressed placental cuproptosis and alleviated miscarriage in CuCl2-exposed mice. This work provides novel reproductive toxicity of Cu exposure in miscarriage or complete pregnancy loss by causing placental cuproptosis. This study also provides new ways for further studies on other toxicological effects of Cu and proposes a new approach for protection against Cu-induced reproductive diseases.

Association of acetaminophen use with perinatal outcomes among pregnant women: a retrospective cohort study with propensity score matching

BACKGROUND

Although acetaminophen is widely used in women during pregnancy, its safety has not been clearly stated. The study aimed to investigate the association between acetaminophen use and adverse pregnancy outcomes in pregnant women in China.

METHODS

We conducted a retrospective cohort study by collecting data on pregnant women who delivered in the Beijing Obstetrics and Gynecology Hospital from January 2018 to September 2023. An acetaminophen use group and a control group were formed based on prenatal exposure to acetaminophen. The pregnancy outcomes that we focused on were stillbirth, miscarriage, preterm birth, APGAR score, birth weight, and congenital disabilities. Pregnant women exposed to acetaminophen were matched to unexposed in a 1:1 ratio with propensity score matching, using the greedy matching macro. SPSS software was used for statistical analysis. Multivariable logistics regression was used to assess the association between acetaminophen use during pregnancy and adverse pregnancy outcomes.

RESULTS

A total of 41,440 pregnant women were included, of whom 501 were exposed to acetaminophen during pregnancy, and 40,939 were not exposed. After the propensity score matching, the acetaminophen use and control groups consisted of 501 pregnant women each. The primary analysis showed that acetaminophen exposure during pregnancy was associated with an increased risk of stillbirth (adjusted OR (aOR) = 2.29, 95% CI, 1.19-4.43), APGAR score < 7 at 1 min (aOR = 3.28, 95% CI, 1.73-6.21), APGAR score < 7 at 5 min (aOR = 3.54, 95% CI, 1.74-7.20), APGAR score < 7 at 10 min (aOR = 3.18, 95% CI, 1.58-6.41), and high birth weight (HBW) (aOR = 1.75, 95% CI, 1.05-2.92). Drug exposure during the first and second trimesters increased the odds of stillbirth, miscarriage, APGAR < 7, and the occurrence of at least one adverse pregnancy outcome. In addition, the frequency of drug use more than two times was associated with a higher risk of preterm birth and APGAR score < 7.

CONCLUSIONS

Exposure to acetaminophen during pregnancy was significantly associated with the occurrence of adverse pregnancy outcomes, particularly exposure in the first and second trimesters and frequency of use more than twice. It is suggested that acetaminophen should be prescribed with caution in pregnant women.

Ambient air pollution and rate of spontaneous abortion

Spontaneous abortion (SAB), defined as a pregnancy loss before 20 weeks of gestation, affects up to 30% of conceptions, yet few modifiable risk factors have been identified. We estimated the effect of ambient air pollution exposure on SAB incidence in Pregnancy Study Online (PRESTO), a preconception cohort study of North American couples who were trying to conceive. Participants completed questionnaires at baseline, every 8 weeks during preconception follow-up, and in early and late pregnancy. We analyzed data on 4643 United States (U.S.) participants and 851 Canadian participants who enrolled during 2013-2019 and conceived during 12 months of follow-up. We used country-specific national spatiotemporal models to estimate concentrations of particulate matter <2.5 μm (PM2.5), nitrogen dioxide (NO2), and ozone (O3) during the preconception and prenatal periods at each participant's residential address. On follow-up and pregnancy questionnaires, participants reported information on pregnancy status, including SAB incidence and timing. We fit Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of time-varying prenatal concentrations of PM2.5, NO2, and O3 with rate of SAB, adjusting for individual- and neighborhood-level factors. Nineteen percent of pregnancies ended in SAB. Greater PM2.5 concentrations were associated with a higher incidence of SAB in Canada, but not in the U.S. (HRs for a 5 μg/m3 increase = 1.29, 95% CI: 0.99, 1.68 and 0.94, 95% CI: 0.83, 1.08, respectively). NO2 and O3 concentrations were not appreciably associated with SAB incidence. Results did not vary substantially by gestational weeks or season at risk. In summary, we found little evidence for an effect of residential ambient PM2.5, NO2, and O3 concentrations on SAB incidence in the U.S., but a moderate positive association of PM2.5 with SAB incidence in Canada.

Benzodiazepine Use During Pregnancy and Risk of Miscarriage

Importance

Benzodiazepine use during pregnancy has raised significant concerns due to the potential harmful effects of this drug class on neonates. Studies on the association between benzodiazepine use and the risk of miscarriage are limited.

Objective

To quantify the risk of miscarriage associated with benzodiazepine use during pregnancy after controlling for unmeasured confounders and exposure time trends.

Design, Setting, and Participants

This was a nationwide, population-based case-time-control study using Taiwan's National Birth Certificate Application database and the National Health Insurance database. Pregnancies resulting in miscarriage between 2004 and 2018 were included in the case group and were 1:1 matched with exposure time-trend control individuals using disease risk score, considering demographic characteristics and prepregnancy comorbidities. Data were analyzed from August 2022 to March 2023.

Exposures

Discordant exposures to benzodiazepines during risk period (1-28 days before miscarriage) and 2 reference periods (31-58 days and 181-208 days before the last menstrual period) were compared for each pregnancy.

Main Outcomes and Measures

Miscarriage was defined as any pregnancy loss occurring between the first prenatal care visit (usually 8 weeks) and the 19th completed week of pregnancy.

Results

This study comprised a total of 3 067 122 pregnancies among 1 957 601 women, 136 134 of which (4.4%) resulted in miscarriage. The mean (SD) age of the study population was 30.61 (5.91) years. The use of benzodiazepines during pregnancy was associated with an increased risk of miscarriage (odds ratio [OR], 1.69; 95% CI, 1.52-1.87), and consistent findings were observed across multiple sensitivity analyses considering different time windows and accounting for misclassification. In subgroup analyses, an increased risk of miscarriage was associated with each commonly used individual benzodiazepine, ranging from case-time-control ORs of 1.39 (95% CI, 1.17-1.66) for alprazolam to 2.52 (95% CI, 1.89-3.36) for fludiazepam.

Conclusions and Relevance

This nationwide case-time-control study revealed an increased risk of miscarriage associated with benzodiazepine use during pregnancy after accounting for measurable confounders, and results were unlikely to be due to unmeasured confounding. These findings underscore the necessity for health care professionals to meticulously balance the risk-benefit ratio when considering the use of benzodiazepines to treat psychiatric and sleep disorders during pregnancy.

Pregnancy outcomes and birth defects in offspring following Non-steroidal anti-inflammatory drugs exposure during pregnancy: A systematic review and meta-analysis

There is a high global prevalence of NSAIDs during pregnancy. However, current evidence is largely conflicting regarding the safety of gestational NSAIDs use both for the pregnancy and offspring health. The aim of this study is to systematically review the relationship between NSAIDs use during pregnancy and the risk of adverse pregnancy outcomes and congenital abnormalities. Cohort studies and case control studies on congenital malformations, miscarriage and preterm birth in infants born to mothers who were exposed to NSAIDs during pregnancy were identified via PubMed, Medline, Embase, the Cochrane Library databases and the Reprotox® database from inception to 26 March 2021, and updated on 6 April 2023. On the whole, compared with the unexposed group, infants exposed to NSAIDs during early pregnancy showed a 28% increased risk of overall congenital anomalies (OR 1.28, 95%CI 1.16-1.40), and 19% for major birth defects (OR 1.19, 95%CI 1.08-1.30). Contrary to previous beliefs, there appeared to be a trend towards a higher risk of miscarriage among women who were exposed to NSAIDs during pregnancy, but the association was not statistically significant (OR 1.20, 95%CI 0.93-1.55). According to our study findings, the use of NSAIDs by pregnant women has been linked to a higher risk of congenital anomalies and a negative impact on preterm birth. Therefore, we advise pregnant women to carefully consider the potential benefits and risks before using NSAIDs during pregnancy.

Adverse Pregnancy Outcomes Among Women with Human Immunodeficiency Virus Taking Isoniazid Preventive Therapy During the First Trimester

BACKGROUND

Isoniazid preventive therapy (IPT) is recommended for tuberculosis prevention yet data on the safety of first-trimester pregnancy exposure are limited.

METHODS

Planned secondary analysis in a TB prevention trial of adverse pregnancy outcomes among participants assigned to 9-month IPT who became pregnant during (IPT-exposed) or after (unexposed) IPT. Regression models compared binary outcomes of a composite adverse outcome (any non-live birth, excluding induced abortion); preterm delivery <37 weeks; and low birth weight <2500 g) among exposure groups. Models were adjusted for latent TB infection, maternal age, CD4 count, and antiretroviral therapy (ART).

RESULTS

In total, 128 participants had a known pregnancy outcome; 39 IPT-exposed and 89 unexposed. At pregnancy outcome, ART use was lower in IPT-exposed (79%) than unexposed women (98%). Overall, 29 pregnancies ended in a composite adverse outcome (25 spontaneous abortions, 2 stillbirths and 2 ectopic pregnancies), 15 preterm deliveries, and 10 infants with low birth weight. IPT was associated with the composite adverse outcome adjusting for covariates at enrollment (adjusted relative risk [aRR] 1.98; 95% confidence interval [CI] 1.15, 3.41), but the effect was attenuated when adjusted for covariates at pregnancy outcome (aRR 1.47; 95% CI .84, 2.55); IPT was not associated with preterm delivery (relative risk [RR] 0.87; 95% CI .32-2.42) or low birth weight (RR 1.01; 95% CI .29, 3.56).

CONCLUSIONS

First-trimester IPT exposure was associated with nearly two-fold increased risk of fetal demise, mostly spontaneous abortion, though the association was attenuated when adjusted for covariates proximal to pregnancy outcome including ART use. Further study is needed to inform TB prevention guidelines.

Potential pathological mechanisms and pharmacological interventions for cadmium-induced miscarriage

The prevalence of cadmium (Cd) contamination has emerged as a significant global concern. Exposure to Cd during pregnancy is associated with adverse pregnancy outcomes, including miscarriage. However, there is currently a lack of comprehensive summaries on Cd-induced miscarriage. Therefore, it is imperative to further strengthen research into in vivo studies, clinical status, pathological mechanisms, and pharmacological interventions for Cd-induced miscarriage. This study systematically presents the current knowledge on animal models and clinical trials investigating Cd exposure-induced miscarriage. The underlying mechanisms involving oxidative stress, inflammation, endocrine disruption, and placental dysfunction caused by Cd-induced miscarriage are also extensively discussed. Additionally, potential drug interventions such as melatonin, vitamin C, and vitamin E are highlighted for their pharmacological role in mitigating adverse pregnancy outcomes induced by Cd.

Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage

BACKGROUND

With rapid increase in the global use of various plastics, microplastics (MPs) and nanoplastics (NPs) pollution and their adverse health effects have attracted global attention. MPs have been detected out in human body and both MPs and NPs showed female reproductive toxicological effects in animal models. Miscarriage (abnormal early embryo loss), accounting for 15-25% pregnant women worldwide, greatly harms human reproduction. However, the adverse effects of NPs on miscarriage have never been explored.

RESULTS

In this study, we identified that polystyrene (PS) plastics particles were present in women villous tissues. Their levels were higher in villous tissues of unexplained recurrent miscarriage (RM) patients vs. healthy control (HC) group. Furthermore, mouse assays further confirmed that exposure to polystyrene nanoplastics (PS-NPs, 50 nm in diameter, 50 or 100 mg/kg) indeed induced miscarriage. In mechanism, PS-NPs exposure (50, 100, 150, or 200 µg/mL) increased oxidative stress, decreased mitochondrial membrane potential, and increased apoptosis in human trophoblast cells by activating Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3 signaling through mitochondrial pathway. The alteration in this signaling was consistent in placental tissues of PS-NPs-exposed mouse model and in villous tissues of unexplained RM patients. Supplement with Bcl-2 could efficiently suppress apoptosis in PS-NPs-exposed trophoblast cells and reduce apoptosis and alleviate miscarriage in PS-NPs-exposed pregnant mouse model.

CONCLUSIONS

Exposure to PS-NPs activated Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3, leading to excessive apoptosis in human trophoblast cells and in mice placental tissues, further inducing miscarriage.

Association between urinary polycyclic aromatic hydrocarbons and unexplained recurrent spontaneous abortion from a case-control study

Polycyclic aromatic hydrocarbons (PAHs) have been reported to be associated with adverse pregnancy outcomes. However, there is limited knowledge regarding the effects of single or mixed PAHs exposure on unexplained recurrent spontaneous abortion (URSA). This study aimed to investigate the association between monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and URSA in a case-control study. The results showed that 1-NAP, 2-NAP, 9-FLU, and 1-PYR were detected in 100% of the subjects among measured all sixteen OH-PAHs. Compared with those in the lowest quartiles, participants in the highest quartiles of 3-BAA were associated with a higher risk of URSA (OR (95%CI) = 3.56(1.28-9.85)). With each one-unit increase of ln-transformed 3-BAA, the odds of URSA increased by 41% (OR (95%CI) = 1.41(1.05-1.89)). Other OH-PAHs showed negative or non-significant associations with URSA. Weighted quantile sum (WQS) regression, Bayesian kernel machine regression (BKMR), and quantile-based g-computation (qgcomp) analyses consistently identified 3-BAA as the major contributor to the mixture effect of OH-PAHs on URSA. Our findings suggest that exposure to 3-BAA may be a potential risk factor for URSA. However, further prospective studies are needed to validate our findings in the future.

The impact of air pollutants on spontaneous abortion: a case-control study in Tongchuan City

OBJECTIVES

Studies related to air pollutants and spontaneous abortion in urban northwestern China are scarce, and the main exposure windows of pollutants acting on pregnant women are unclear.

STUDY DESIGN

Case-control study.

METHODS

Data were collected from pregnant women in Tongchuan City from 2018 to 2019. A total of 289 cases of spontaneous abortion and 1156 cases of full-term labor were included and analyzed using a case-control study. Logistic regression models were developed to explore the relationship between air pollutants and spontaneous abortion after Chi square analysis and Air pollutant description.

RESULTS

O3 (odds ratio [OR] = 1.028) is a risk factor for spontaneous abortion throughout pregnancy. PM2.5 (OR = 1.015), PM10 (OR = 1.010), SO2 (OR = 1.026), and NO2 (OR = 1.028) are risk factors for spontaneous abortion in the 30 days before the last menstrual period. PM2.5 (OR = 1.015), PM10 (OR = 1.013), SO2 (OR = 1.036), and NO2 (OR = 1.033) are risk factors for spontaneous abortion in the 30-60 days before the last menstrual period. PM2.5 (OR = 1.028), PM10 (OR = 1.013), SO2 (OR = 1.035), and NO2 (OR = 1.059) are risk factors for spontaneous abortion in the 60-90 days before the last menstrual period.

CONCLUSION

Exposure to high levels of air pollutants may be a cause of increased risk of spontaneous abortion, especially in the first trimester of the last menstrual period.

Final analysis of 379 pregnancy outcomes after exposure to dimethyl fumarate in a prospective international registry

BACKGROUND

Dimethyl fumarate (DMF) has a favorable benefit-risk profile treating people with multiple sclerosis and should be used in pregnant women only if the potential benefits outweigh potential risks to the fetus.

OBJECTIVE

Assess pregnancy outcomes in a completed international registry (TecGistry) of women with MS exposed to DMF.

METHODS

TecGistry included pregnant women with MS exposed to DMF, with data collected at enrollment, 6-7 months gestation, 4 weeks after estimated due date, and at postpartum weeks 4, 12, and 52. Outcomes included live births, gestational size, pregnancy loss, ectopic/molar pregnancies, birth defects, and infant/maternal death.

RESULTS

Of 397 enrolled, median (range) age was 32 years (19-43). Median (range) gestational week at enrollment was 10 (0-39) and at first DMF exposure was 1 (0-13). Median (range) duration of gestational DMF exposure was 5 weeks (0-40). Fifteen (3.8%) spontaneous abortions occurred. Of 360 (89.1%) live births, 323 were full term and 37 were premature. One neonatal death and no maternal deaths occurred. Adjudicator-confirmed EUROCAT birth defects were found in 2.2%.

CONCLUSION

DMF exposure during pregnancy did not adversely affect pregnancy outcomes; birth defects, preterm birth, and spontaneous abortion were in line with rates from the general population.

Association between antidepressant use during pregnancy and miscarriage: a systematic review and meta-analysis

BACKGROUND

Literature surrounding the association between antidepressant use during pregnancy and miscarriage is conflicting. We aimed to conduct a systematic review and meta-analysis of studies among pregnant women regarding the association between exposure to antidepressants during pregnancy and the risk of miscarriage, compared with pregnant women not exposed to antidepressants.

DESIGN

We conducted a systematic review and meta-analysis of non-randomised studies.

DATA SOURCES

We searched Medline, Embase and PsychINFO up to 6 August 2023.

ELIGIBILITY CRITERIA AND OUTCOMES

Case-control, cohort and cross-sectional study designs were selected if they compared individuals exposed to any antidepressant class during pregnancy to comparator groups of either no antidepressant use or an alternate antidepressant.

DATA EXTRACTION AND SYNTHESIS

Effect estimates were extracted from selected studies and pooled using a random-effects meta-analysis. Risk of bias (RoB) was assessed using the Risk of Bias in Non-Randomised Studies of Interventions (ROBINS-I) tool, and heterogeneity assessed using the I2 statistic. Subgroup analyses were used to explore antidepressant classes and the impact of confounding by indication.

RESULTS

1800 records were identified from the search, of which 29 were included in the systematic review and meta-analysis. The total sample included 5 671 135 individuals. Antidepressant users initially appeared to have a higher risk of miscarriage compared with unexposed individuals from the general population (summary effect estimate: 1.24, 95% CI 1.18 to 1.31, I2=69.2%; number of studies (n)=29). However, the summary estimate decreased when comparing against unexposed individuals with maternal depression (1.16, 1.04 to 1.31; I2=58.6%; n=6), suggesting confounding by indication may be driving the association. 22 studies suffered from serious RoB, and only two of the 29 studies were deemed at moderate RoB.

CONCLUSIONS

After accounting for maternal depression, there is little evidence of any association between antidepressant use during pregnancy and miscarriage. Instead, the results indicate the biasing impact of confounding by indication.

Influence of maternal endocrine disrupting chemicals exposure on adverse pregnancy outcomes: A systematic review and meta-analysis

Maternal endocrine disrupting chemicals (EDCs) exposure, the common environmental pollutants, was capable of involving in adverse pregnancy outcomes. However, the evidence of their connection is not consistent. Our goal was to comprehensively explore the risk of EDCs related to adverse pregnancy outcomes. One hundred and one studies were included from two databases before 2023 to explore the association between EDCs and adverse pregnancy outcomes including miscarriage, small for gestational age (SGA), low birth weight (LBW) and preterm birth (PTB). We found that maternal PFASs exposure was positively correlated with PTB (OR:1.13, 95% CI:1.04-1.23), SGA (OR:1.10, 95% CI:1.04-1.16) and miscarriage (OR:1.09, 95% CI:1.00-1.19). The pooled estimates also showed maternal PAEs exposure was linked with PTB (OR:1.16, 95% CI:1.11-1.21), SGA (OR:1.20, 95% CI:1.07-1.35) and miscarriage (OR:1.55, 95% CI:1.33-1.81). In addition, maternal exposure to some specific class of EDCs including PFOS, MBP, MEHP, DEHP, and BPA was associated with PTB. Maternal exposure to PFOS, PFOA, PFHpA was associated with SGA. Maternal exposure to BPA was associated with LBW. Maternal exposure to MMP, MEHP, MEHHP, MEOHP, BPA was associated with miscarriage. Maternal PFASs, PAEs and BPA exposure may increase adverse pregnancy outcomes risk according to our study. However, the limited number of studies on dose-response hampered further explanation for causal association.

Impact of maternal first trimester treatment regimen on the outcome of valproate exposed pregnancies: an observational Embryotox cohort study

Effects of valproate (VPA) dose and treatment discontinuation during the first trimester of pregnancy on the risks of spontaneous abortions (SAB) and major birth defects were analyzed. Pregnancies with first trimester VPA exposure (n = 484) prospectively recorded by the German Embryotox center in 1997-2016 were compared with a randomly selected, non-exposed cohort (n = 1446). The SAB risk was not significantly increased in the VPA cohort [HRadj 1.31 (95% CI 0.85-2.02)] but major birth defects were significantly more frequent [8.7% vs. 3.4%; ORadj 2.61 (95% CI 1.51-4.50)]. Risk was even higher in pregnancies with no VPA discontinuation in first trimester [ORadj 3.66 (95% CI 2.04-6.54)]. Significant ORs were found for nervous system defects in general [ORadj 5.69 (95% CI 1.73-18.78)], severe microcephaly [ORadj 6.65 (95% CI 1.17-37.68)], hypospadias [ORadj 19.49 (95% CI 1.80-211)] and urinary system defects [ORadj 6.51 (95% CI 1.48-28.67)]. VPA dose had a stronger effect than antiepileptic poly- versus monotherapy; for VPA dose ≥ 1500 mg/day the ORadj was 5.41 (95% CI 2.32-12.66)]. A daily dose increase of 100 mg was calculated to raise the risk for major birth defects by 15% [OR 1.15 (95% CI 1.08-1.23)]. Overall, maternal first trimester treatment regimen had a relevant impact on birth defect risk.

Prenatal Exposure to Air Pollution and Respiratory Distress in Term Newborns: Results from the MIREC Prospective Pregnancy Cohort

BACKGROUND

Respiratory distress is the leading cause of neonatal morbidity and mortality worldwide, and prenatal exposure to air pollution is associated with adverse long-term respiratory outcomes; however, the impact of prenatal air pollution exposure on neonatal respiratory distress has not been well studied.

OBJECTIVES

We examined associations between prenatal exposures to fine particular matter (PM 2.5 ) and nitrogen dioxide (NO 2 ) with respiratory distress and related neonatal outcomes.

METHODS

We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a prospective pregnancy cohort (n = 2,001 ) recruited in the first trimester from 10 Canadian cities. Prenatal exposures to PM 2.5 (n = 1,321 ) and NO 2 (n = 1,064 ) were estimated using land-use regression and satellite-derived models coupled with ground-level monitoring and linked to participants based on residential location at birth. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between air pollution and physician-diagnosed respiratory distress in term neonates in hierarchical logistic regression models adjusting for detailed maternal and infant covariates.

RESULTS

Approximately 7 % of newborns experienced respiratory distress. Neonates received clinical interventions including oxygen therapy (6%), assisted ventilation (2%), and systemic antibiotics (3%). Two percent received multiple interventions and 4% were admitted to the neonatal intensive care unit (NICU). Median PM 2.5 and NO 2 concentrations during pregnancy were 8.81   μ g / m 3 and 18.02  ppb , respectively. Prenatal exposures to air pollution were not associated with physician-diagnosed respiratory distress, oxygen therapy, or NICU admissions. However, PM 2.5 exposures were strongly associated with assisted ventilation (OR per 1 - μ g / m 3 increase in PM 2.5 = 1.17 ; 95% CI: 1.02, 1.35), multiple clinical interventions (OR per 1 - μ g / m 3 increase in PM 2.5 = 1.16 ; 95% CI: 1.07, 1.26), and systemic antibiotics, (OR per 1 - μ g / m 3 increase in PM 2.5 = 1.12 ; 95% CI: 1.04, 1.21). These associations were consistent across exposure periods-that is, during prepregnancy, individual trimesters, and total pregnancy-and robust to model specification. NO 2 exposure was associated with administration of systemic antibiotics (OR per 1-ppb increase in NO 2 = 1.03 ; 95% CI: 1.00, 1.06).

DISCUSSION

Prenatal exposures to PM 2.5 increased the risk of severe respiratory distress among term newborns. These findings support the development and prioritization of public health and prenatal care strategies to increase awareness and minimize prenatal exposures to air pollution. https://doi.org/10.1289/EHP12880.

Antiepileptic treatment with levetiracetam during the first trimester and pregnancy outcome: An observational study

OBJECTIVE

Levetiracetam is increasingly used in pregnant women with epilepsy. Although teratogenic effects have not been observed so far, data on the risks of spontaneous abortion and major birth defects are still limited, especially for the frequently used dual therapy of levetiracetam and lamotrigine. Our primary aim was to analyze rates of major birth defects and spontaneous abortion after maternal levetiracetam treatment.

METHODS

This was a cohort study based on pregnancies recorded by the Embryotox Center from 2000 to 2017. Outcomes of prospectively ascertained pregnancies with first trimester levetiracetam monotherapy (n = 221) were compared to pregnancies with lamotrigine monotherapy for epilepsy (n = 469). In addition, all pregnancies with levetiracetam (n = 364) exposure during the first trimester were analyzed in comparison to a nonexposed cohort (n = 729). Pregnancies with the most frequently used combination therapy comprising levetiracetam and lamotrigine (n = 80) were evaluated separately.

RESULTS

There was no significantly increased risk of major birth defects or of spontaneous abortions after first trimester exposure to levetiracetam. Birth weight of male neonates was significantly lower after levetiracetam monotherapy compared to lamotrigine monotherapy. Dual therapy with levetiracetam and lamotrigine resulted in a significantly increased risk of spontaneous abortion (adjusted hazard ratio = 3.01, 95% confidence interval [CI] = 1.43-6.33) and a nonsignificant effect estimate for major birth defects (7.7%, n = 5/65, adjusted odds ratio = 1.47, 95% CI = .48-4.47) compared to a nonexposed cohort.

SIGNIFICANCE

Our study confirms the use of levetiracetam as a suitable antiepileptic drug in pregnancy. The lower birth weight of male neonates after maternal levetiracetam monotherapy and the unexpectedly high risk of spontaneous abortion and birth defects after dual therapy with levetiracetam and lamotrigine require further investigation.

The risk of miscarriage after COVID-19 vaccination before and during pregnancy

PURPOSE

Pregnant women are at higher risk of severe illness and adverse pregnancy outcomes due to a SARS-CoV-2 infection, which can be prevented by vaccination. Observational studies are needed to ascertain the safety of COVID-19 vaccination during pregnancy. We aimed to determine whether COVID-19 vaccination before and during pregnancy is associated with the risk of miscarriage.

METHODS

In this cohort study, we included 4640 pregnant women (mean age: 32.8 ± 3.7 years) from the Dutch Pregnancy Drug Register between February 2021 and August 2022. Information on COVID-19 vaccinations, miscarriage, and confounders was self-reported, using web-based questionnaires. The hazard ratio (HR) of miscarriage (in gestational weeks 6-20) after a COVID-19 vaccination, was estimated using the survival analyses. A COVID-19 vaccination during pregnancy (≥1 COVID-19 vaccination between week 2 and 20 of pregnancy) was included as a time-dependent exposure and vaccination prior to pregnancy was included as a binary exposure.

RESULTS

A total of 3202 pregnant women (69%) received ≥1 COVID-19 vaccine in gestational week 2-20. We observed no association of vaccination during pregnancy with the risk of miscarriage (adjusted HR = 1.29, 95% CI = 0.93-1.74). Vaccination prior to pregnancy, however, was associated with a decreased risk of miscarriage (adjusted HR = 0.69, 95% CI = 0.48-0.99).

CONCLUSIONS

We demonstrated that COVID-19 vaccination during pregnancy is not associated with an increased risk of miscarriage in gestational weeks 6-20. This study adds to the growing body of evidence demonstrating the safety of COVID-19 vaccination during pregnancy.

How to account for early overly small risk sets in the analysis of pregnancy outcome data?-Comparison of different methods for stabilizing the Aalen-Johansen estimator

PURPOSE

In analyzing pregnancy data concerning drug exposure in the first trimester, the risk of spontaneous abortions is of primary interest. For estimating the cumulative incidence function, the Aalen-Johansen estimator is typically used, and competing risks such as induced abortion and livebirth are considered. However, the delayed study entry can lead to overly small risk sets for the first events. This results in large jumps in the estimated cumulative incidence function of spontaneous abortions or induced abortions using the Aalen-Johansen estimator, and consequently in an overestimation of the probability.

METHODS

Several approaches account for early overly small risk sets. The first approach is conditioning on the event time being greater than the event time causing the large jump. Second, the events can be ignored by censoring them. Third, the events can be postponed until a large enough number is at risk. These three approaches are compared.

RESULTS

All approaches are applied using data of 54 lacosamide-exposed pregnancies. The Aalen-Johansen estimate of the probability of spontaneous abortion is 22.64%, which is relatively large for only three spontaneous abortions in the dataset. The conditional approach and the ignore approach have an estimated probability of 7.17%. In contrast, the estimate of the postpone approach is 16.45%. In this small sample, bootstrapped confidence intervals seem more accurate.

CONCLUSIONS

In the analyses of pregnancy data with rare events, the postpone approach is favorable as no events are excluded. However, the approach that ignores early events has the narrowest confidence interval.

Preconception Phthalate Exposure and Women's Reproductive Health: Pregnancy, Pregnancy Loss, and Underlying Mechanisms

BACKGROUND

Phthalates are endocrine-disrupting chemicals linked to adverse pregnancy outcomes. Despite the sensitivity of female reproductive processes to oxidation-reduction reaction stress and endocrine disruption, evidence for the impact of women's phthalate exposure on the ability to establish and maintain pregnancy has been inconclusive.

OBJECTIVES

We aimed to determine the relationship of preconception phthalate metabolite exposure with a) fecundability and pregnancy loss and b) markers of potential biological mechanisms, including reproductive hormones, inflammation, and oxidative stress.

METHODS

Data were collected from the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, a preconception study following 1,228 women who were attempting pregnancy, for up to six menstrual cycles and throughout pregnancy if they became pregnant. Twenty phthalate metabolites were measured in a consecutive 3-d pooled urine sample at enrollment. Pregnancy was determined through urinary human chorionic gonadotropin (hCG) at the expected date of menses during each cycle and pregnancy loss as an observed loss following positive hCG. Highly sensitive C-reactive protein (hsCRP) and isoprostanes were measured at enrollment, and reproductive hormones were measured during the follicular phase, ovulation, and luteal phase. Discrete-time Cox proportional hazards models evaluated the relationship of phthalate metabolites with fecundability and weighted Poisson models with robust variance evaluated the risk of pregnancy loss.

RESULTS

An interquartile range (IQR) higher mono-(2-ethylhexyl) phthalate [fecundability odds ratio  ( FOR ) = 0.88 ; 95% confidence interval (CI): 0.78, 1.00], mono-butyl phthalate (FOR = 0.82 ; 95% CI: 0.70, 0.96), and mono-benzyl phthalate (FOR = 0.85 ; 95% CI: 0.74, 0.98) was associated with lower fecundability. No consistent associations were observed with pregnancy loss. Preconception phthalates were consistently associated with higher hsCRP and isoprostanes, as well as lower estradiol and higher follicle-stimulating hormone across the menstrual cycle.

DISCUSSION

Women's preconception exposure to phthalates was associated with lower fecundability, changes in reproductive hormones, and increased inflammation and oxidative stress. The pre- and periconception periods may represent sensitive windows for intervening to limit the reproductive toxicity of phthalate exposure. https://doi.org/10.1289/EHP12287.

The role of seminal reactive oxygen species assessment in the setting of infertility and early pregnancy loss

The male contribution to a couple suffering with adverse early pregnancy outcomes is being increasingly investigated. Seminal oxidative stress is considered to cause sperm DNA damage, thus affecting the functional capacity of the sperm. Multiple lines of evidence support an association between elevated seminal reactive oxygen species (ROS) and infertility. In the setting of assisted reproduction various factors in the in vitro environment, differing from the in vivo environment, may exacerbate oxidative stress. Furthermore, seminal ROS levels have been found to be higher in the male partners of couple's affected by both spontaneous and recurrent pregnancy loss. There are several methods by which to assess ROS levels however they are costly, inconsistent and their incorporation into clinical practice is unclear. The value of ROS assessment lies in the ability to plan targeted therapies to improve pregnancy and live birth rates. As such, further robust study is required before firm conclusions can be made to inform clinical practice. We aim to review the available evidence regarding the role of seminal ROS in infertility and pregnancy loss.

Effect of short-term ambient air pollution exposure on early miscarriage and pregnancy hormones with critical window identification

BACKGROUND

Pregnancy hormones are particularly important in early miscarriage, and some evidence suggests that exposure to air pollution is associated with pregnancy hormones and miscarriage. However, the effects of air pollution on pregnancy hormone-mediated miscarriages have not yet been investigated.

METHODS

We collected air pollution exposure measurements and pregnancy hormone tests from the participants. Logistic regression models were used to investigate the association between air pollution and early miscarriages. A distributed lag nonlinear model (DLNM) was used to investigate non-linear and delayed associations and identify the crucial window. We performed mediation analysis to estimate the potential association that may exist between pregnancy hormone levels and early miscarriage.

RESULTS

Short-term exposure to CO and SO2 was associated with early miscarriage. Lag 22-28 days of exposure to both CO and SO2 and lag 15-21 days of exposure to CO were significantly positively associated with early miscarriage, with an obvious exposure dose response. Serum progesterone concentration explained 36.79 % of the association between lag 15-28 days of CO exposure and early miscarriage.

CONCLUSION

This study provides evidence for the association between short-term exposure to air pollution and early miscarriage, and provides clues for further exploration of biological mechanisms.

The association between history of retained placenta and success rate of misoprostol treatment for early pregnancy failure

BACKGROUND

To date, the association between retained placenta and treatment success rate of misoprostol for early pregnancy failure has yet to be evaluated. The aim of this study was to evaluate this association and further investigated the connection between medical, clinical and sonographic parameters and treatment success.

METHODS

We conducted a retrospective cohort study of women with early pregnancy failure treated with misoprostol from 2006 to 2021. The success rate of misoprostol treatment was compared between patients with history of retained placenta including women who underwent manual lysis of the placenta following delivery or patients who were found to have retained products of conception during their post-partum period (study group) and patients without such history (controls). Demographic, clinical, and sonographic characteristics as well as treatment outcomes were compared between the groups.

RESULTS

A total of 271 women were included in the study (34 women in the study group compared to 237 women in the control group). Two-hundred and thirty-three women (86.0%) presented with missed abortion, and 38 (14.0%) with blighted ovum. Success rates of misoprostol treatment were 61.8% and 78.5% for the study and control groups, respectively (p = 0.032). Univariate analysis performed comparing successful vs. failed misoprostol treatment showed advanced age, gravidity, parity and gestational sac size (mm) on TVUS were associated with higher misoprostol treatment failure rate. Following a multivariate logistic regression model these variables did not reach statistical significance.

CONCLUSION

Women who have an event of retained placenta following childbirth appear to have decreased success rate of treatment with misoprostol for early pregnancy failure. Larger studies are needed to confirm this finding.

Medication Abortion Safety and Effectiveness With Misoprostol Alone

Importance

Misoprostol-alone regimens for abortion may be more effective than previously thought.

Objective

To estimate the effectiveness of medication abortion with misoprostol alone among individuals self-managing their abortion.

Design, Setting, and Participants

For this prospective observational cohort study of callers to safe abortion hotlines and accompaniment groups in Argentina, Nigeria, and Southeast Asia, participants were recruited between July 31, 2019, and October 1, 2020, prior to starting their medication abortion. Eligible participants were 13 years or older, had no contraindications to medication abortion, and were not currently bleeding. Participants completed a baseline and 2 follow-up surveys. The analysis was restricted to participants who reported using misoprostol alone and was performed between January 6, 2022 and September 8, 2023.

Exposure

Self-managed medication abortion using misoprostol alone.

Main Outcomes and Measures

The primary outcome was effectiveness, defined as participant self-report of complete abortion without procedural intervention, measured at 1 week and 3 weeks after taking misoprostol. Secondary outcomes included method safety, measured by self-report of experiencing warning signs (eg, heavy bleeding, pain, fever, discharge) indicative of a potential complication and by medical treatment (eg, blood transfusion, intravenous fluids, overnight hospital stay) indicative of a potential adverse event. Additional outcomes included length of bleeding and cramping, time to expulsion, and experience of adverse effects.

Results

Among 1352 enrolled participants, 637 used misoprostol-alone regimens for abortion and were included in the analysis (591 [92.8%] from Nigeria, 45 [7.1%] from Southeast Asia, and 1 [0.2%] from Argentina; 384 [60.2%] aged 20-29 years; 317 [49.8%] with pregnancy durations <7 weeks and 205 [32.2%] with pregnancy durations between 7 and <9 weeks). At last follow-up after taking medication (median, 22 days; IQR, 21-26 days), 625 participants (98.1%; 95% CI, 96.7%-98.9%) had a complete abortion without procedural intervention. Potential adverse events were reported by 6 participants (0.9%; 95% CI, 0.4%-2.1%). Most participants experienced bleeding for less than 1 week (median, 4 days; IQR, 3-6 days) and expelled their pregnancy within 24 hours of starting the abortion process (median, 12 hours; IQR, 9-15 hours). Common side effects included nausea (335 participants [52.6%]), fever (232 [36.4%]), and diarrhea (181 [28.4%]).

Conclusions and Relevance

The findings suggest that misoprostol alone is a highly effective method of pregnancy termination. Future research should explore strategies to maximize the effectiveness of misoprostol alone in clinical and nonclinical settings.

Exposure to biologic therapy before and during pregnancy in patients with psoriasis: Systematic review and meta-analysis

Biologicals have transformed the management of severe disease phenotypes in psoriasis and are often prescribed in women of childbearing age. However, information on safety of biologicals in pregnancy are lacking. We conducted a systematic review and meta-analysis aimed to describe the characteristics and pregnancy outcomes in women with psoriasis exposed to biologics within 3 months before or during pregnancy, and to estimate the pooled prevalence of spontaneous, elective and total abortions, and congenital malformations in their newborns. Bibliographic searches were performed in the PubMed, Embase, Scopus and Web of Science databases up to 14 April 2022. No restrictions on sample size or publication date were applied. Review performance complied with PRISMA guidelines, and two reviewers assessed randomized controlled trials and nonrandomized studies reporting pregnancy outcomes in women exposed to biologics indicated for psoriasis during the pre-gestational and/or gestational period. Studies focusing on rheumatologic or gastroenterological immune-mediated inflammatory diseases were excluded. Regardless of data heterogeneity, a random-effects model was used to pool prevalence estimates. We included 51 observational studies, involving 739 pregnancies exposed to approved biologics for psoriasis. Administration was mostly (70.4%) limited to the first trimester, and the most common drug was ustekinumab (36.0%). The estimated prevalence of miscarriage was 15.3% (95% confidence interval [CI] 12.7-18.0) and elective abortions, 10.8% (95% CI 7.7-14.3). Congenital malformations occurred in about 3.0% (95% CI 1.6-4.8) of live births exposed to biologics during pregnancy. Altogether, exposure to biologics for psoriasis during pregnancy and/or conception does not seem to be associated with an increased risk of miscarriage/abortion or congenital malformations, showing similar rates to the general population. These results suggest that biologic drugs are safe and pose an acceptable risk to the foetuses/neonates.

Association of blood cadmium and lead levels with self-reported reproductive lifespan and pregnancy loss: The national health and nutrition examination survey 1999-2018

Cadmium and lead are known to interfere with the endocrine function. Thus, hormonally regulated processes such as menarche, menopause and pregnancy are likely influenced by chronic exposure to these metals. In US post-menopausal women, who already completed their reproductive lifespan, we evaluated the association between blood cadmium and lead levels with self-reported reproductive lifespan and personal history of pregnancy loss. We selected 5317 post-menopausal women participating in the National Health and Nutrition Examination Survey (NHANES), 1999-2018. Blood cadmium and lead levels were measured by inductively coupled plasma mass spectrometry. Reproductive lifespan was defined as the number of years between self-reported age at menarche and menopause. Personal history of pregnancy loss was defined as number of self-reported pregnancy losses out of the self-reported number of pregnancies. The fully adjusted mean difference in reproductive lifespan (95% confidence interval [CI]) comparing the 80th to the 20th percentiles of blood cadmium and lead distributions was, respectively, 0.50 (0.10, 0.91) and 0.72 (0.41, 1.03) years. Ever smoker showed stronger association of blood lead with reproductive lifespan. For self-reported pregnancy loss, the corresponding fully adjusted relative prevalence (95% CI) was 1.10 (0.93, 1.31) for cadmium and 1.10 (1.00, 1.21) for lead, and remained similar after additional adjustment for reproductive lifespan. In never smokers, the relative prevalence was 1.07 (1.04, 1.11) and 1.16 (1.05, 1.28) for blood cadmium and lead, respectively. These findings suggest that blood cadmium and lead exposures increase reproductive lifespan and prevalence of pregnancy loss in the general population. Additional studies are needed to improve the understanding of mechanisms and prevention potential of metals-related pregnancy outcomes.

COVID-19 Vaccine Safety Surveillance in Early Pregnancy in the United States: Design Factors Affecting the Association Between Vaccine and Spontaneous Abortion

In the Vaccine Safety Datalink (VSD), we previously reported no association between coronavirus disease 2019 (COVID-19) vaccination in early pregnancy and spontaneous abortion (SAB). The present study aims to understand how time since vaccine rollout or other methodological factors could affect results. Using a case-control design and generalized estimating equations, we estimated the odds ratios (ORs) of COVID-19 vaccination in the 28 days before a SAB or last date of the surveillance period (index date) in ongoing pregnancies and occurrence of SAB, across cumulative 4-week periods from December 2020 through June 2021. Using data from a single site, we evaluated alternative methodological approaches: increasing the exposure window to 42 days, modifying the index date from the last day to the midpoint of the surveillance period, and constructing a cohort design with a time-dependent exposure model. A protective effect (OR = 0.78, 95% confidence interval: 0.69, 0.89), observed with 3-cumulative periods ending March 8, 2021, was attenuated when surveillance extended to June 28, 2021 (OR = 1.02, 95% confidence interval: 0.96, 1.08). We observed a lower OR for a 42-day window compared with a 28-day window. The time-dependent model showed no association. Timing of the surveillance appears to be an important factor affecting the observed vaccine-SAB association.

Effects of a LPG stove and fuel intervention on adverse maternal outcomes: A multi-country randomized controlled trial conducted by the Household Air Pollution Intervention Network (HAPIN)

Household air pollution from solid cooking fuel use during gestation has been associated with adverse pregnancy and birth outcomes. The Household Air Pollution Intervention Network (HAPIN) trial was a randomized controlled trial of free liquefied petroleum gas (LPG) stoves and fuel in Guatemala, Peru, India, and Rwanda. A primary outcome of the main trial was to report the effects of the intervention on infant birth weight. Here we evaluate the effects of a LPG stove and fuel intervention during pregnancy on spontaneous abortion, postpartum hemorrhage, hypertensive disorders of pregnancy, and maternal mortality compared to women who continued to use solid cooking fuels. Pregnant women (18-34 years of age; gestation confirmed by ultrasound at 9-19 weeks) were randomly assigned to an intervention (n = 1593) or control (n = 1607) arm. Intention-to-treat analyses compared outcomes between the two arms using log-binomial models. Among the 3195 pregnant women in the study, there were 10 spontaneous abortions (7 intervention, 3 control), 93 hypertensive disorders of pregnancy (47 intervention, 46 control), 11 post postpartum hemorrhage (5 intervention, 6 control) and 4 maternal deaths (3 intervention, 1 control). Compared to the control arm, the relative risk of spontaneous abortion among women randomized to the intervention was 2.32 (95% confidence interval (CI): 0.60, 8.96), hypertensive disorders of pregnancy 1.02 (95% CI: 0.68, 1.52), postpartum hemorrhage 0.83 (95% CI: 0.25, 2.71) and 2.98 (95% CI: 0.31, 28.66) for maternal mortality. In this study, we found that adverse maternal outcomes did not differ based on randomized stove type across four country research sites.

Maternal antipsychotic use during pregnancy and congenital malformations

BACKGROUND

Existing data may underestimate the potential teratogenic effects of prenatal antipsychotic exposure because of lacking data on miscarriages and induced abortions.

OBJECTIVE

This study aimed to present a comprehensive analysis based on information on pregnancies ending in termination, miscarriage, stillbirth, and live birth.

STUDY DESIGN

We conducted a population-based cohort study in Denmark of clinically recognized singleton pregnancies with the first-trimester scan performed from 2008 to 2017. We compared the risk of major malformations between pregnancies exposed to antipsychotics in the first trimester and unexposed pregnancies. In secondary analyses, the comparison was made with pregnancies of women who used antipsychotics before but not during pregnancy (discontinuers). We used weighted log-binomial regression to estimate adjusted prevalence ratios and propensity score fine stratifications for confounding control. We performed 4 sensitivity analyses, including a sibling-controlled analysis.

RESULTS

Of the 503,158 pregnancies, 1252 (0.2%) were of women who filled an antipsychotic prescription in the first trimester. Major malformations were present in 7.3% of antipsychotic-exposed pregnancies, 5.1% of unexposed pregnancies, and 6.0% of discontinuers' pregnancies. The adjusted prevalence ratio was 1.23 (95% confidence interval, 1.01-1.50) among exposed pregnancies compared with unexposed pregnancies. The prevalence ratio was attenuated to 1.14 (95% confidence interval, 0.88-1.48) compared with discontinuers and 1.08 (95% confidence interval, 0.47-2.49) in the sibling analysis. Similar findings were observed with cardiac malformations. Results were consistent for classes and individual antipsychotics, and remained robust across the 4 sensitivity analyses.

CONCLUSION

Our findings suggest limited or no overall teratogenic effect of first-trimester antipsychotic exposure. For individual antipsychotics, with estimations based on very few cases, further studies with sufficient sample sizes are warranted.

Effects of maternal antenatal treatment with two doses of azithromycin added to monthly sulfadoxine-pyrimethamine for the prevention of low birth weight in Burkina Faso: an open-label randomized controlled trial

BACKGROUND

Exposure during pregnancy to malaria and sexually-transmitted infections is associated with adverse birth outcomes including low birth weight (LBW). This study aimed at assessing if the adjunction of two doses of azithromycin to sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy can reduce LBW.

METHODS

A two parallel-groups, open-label randomized controlled trial involving pregnant women (16 to 35 years of age and 12 to 24 weeks of gestation as confirmed by last menstrual period or fundal height) was conducted in rural Burkina Faso. Women were assigned in a 1:1 ratio either to use azithromycin (1 g daily for 2 days) during the second and third trimesters of pregnancy plus monthly sulfadoxine-pyrimethamine (1500/75 mg) (SPAZ) (intervention) or to continue using a monthly sulfadoxine-pyrimethamine (1500/75 mg) (SP) (control). Primary outcome was a LBW (birth weight measured within 24 h after birth < 2500 g). Secondary outcomes including stillbirth, preterm birth or miscarriage are reported together with safety data.

RESULTS

A total of 992 pregnant women underwent randomization (496 per group) and 898 (90.5%) valid birth weights were available (450 in SPAZ and 448 in SP). LBW incidence was 8.7% (39/450) in SPAZ and 9.4% (42/448) in controls (p-value = 0.79). Compared with controls, pregnant women with SPAZ showed a risk ratio (RR) of 1.16 (95% confidence interval (CI 0.64-2.08]) for preterm births, 0.75 (95% CI 0.17-3.35) for miscarriage and 0.64 (95% CI 0.25-1.64) for stillbirths. No treatment-related serious adverse events (SAEs) have been observed, and there was no significant difference in the number of SAEs (13.5% [67/496] in SPAZ, 16.7% [83/496] in SP, p-value = 0.18) or AEs (17.1% [85/496] in SPAZ, 18.8% [93/496] in SP, p-value = 0.56).

CONCLUSION

Adequate prevention regimen with monthly sulfadoxine-pyrimethamine given to all pregnant women has been proved to reduce the risk of LBW in malaria endemic areas. Adding azithromycin to the regimen does not offer further benefits, as far as women receive a malaria prevention regimen early enough during pregnancy. Trial registration Pan African Clinical Trial Registry ( https://pactr.samrc.ac.za/Search.aspx ): PACTR201808177464681. Registered 21 August 2018.

Periconceptional antibiotic use and spontaneous abortion: A prospective cohort study

BACKGROUND

Many reproductive-aged North Americans use antibiotics in the weeks preceding conception or during early pregnancy. Antibiotic use may influence risk of spontaneous abortion (SAB) by disrupting the reproductive tract microbiome or treating harmful infections. However, this association has not been extensively studied.

OBJECTIVE

To determine the extent to which periconceptional antibiotic use is associated with the risk of SAB.

METHODS

We analysed data from an internet-based preconception cohort study of pregnancy planners. Eligible participants self-identified as female, were aged 21-45 years, resided in the USA or Canada, and conceived during 12 months of follow-up (n = 7890). Participants completed an enrolment questionnaire during June 2013-September 2021 and bimonthly follow-up questionnaires for up to 12 months or until a reported pregnancy, whichever came first. Pregnant participants completed questionnaires in early (~8-9 weeks) and late (~32 weeks) gestation. We assessed antibiotic use, including type (penicillins, nitrofurantoin, cephalosporins and macrolides) and indication for use, during the previous 4 weeks on preconception questionnaires. Participants reported pregnancies and SAB on follow-up and pregnancy questionnaires. We used Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between periconceptional antibiotic use and SAB, controlling for potential demographic, medical, and lifestyle confounders.

RESULTS

Nineteen percent (n = 1537) of pregnancies ended in SAB. Participants reported periconceptional antibiotic use in 8% of pregnancies ending in SAB and 7% not ending in SAB. Periconceptional antibiotic use was not appreciably associated with SAB (adjusted HR 1.06, 95% CI 0.88, 1.28). We observed no strong associations between antibiotic type, indication for use, or recency of exposure and SAB risk.

CONCLUSIONS

Periconceptional antibiotic use was not appreciably associated with SAB in this study. This association is likely complicated by antibiotic type and dosage, timing of conception, and the individual's overall health.

Exposure to thioguanine during 117 pregnancies in women with inflammatory bowel disease

BACKGROUND

Safety of thioguanine in pregnant patients with inflammatory bowel disease (IBD) is sparsely recorded. This study was aimed to document the safety of thioguanine during pregnancy and in birth.

METHODS

In this multicenter case series, IBD patients treated with thioguanine during pregnancy were included. Data regarding disease and medication history, pregnancy course, obstetric complications and neonatal outcomes were collected.

RESULTS

Data on 117 thioguanine-exposed pregnancies in 99 women were collected. Most (78%) had Crohn's disease and the mean age at delivery was 31 years. In eighteen pregnancies (15%) IBD flared. Obstetric and infectious complications were seen in 15% (n=17) and 7% (n=8) of pregnancies, respectively. Ten pregnancies (8.5%) resulted in a first trimester miscarriage and one in a stillbirth at 22 weeks gestational age. Congenital abnormalities were observed in one induced abortion (trisomy 21) and in one of the live-born children (cleft palate) . In total 109 neonates were born from 101 singleton pregnancies and 4 twin pregnancies. In the singleton pregnancies, ten children were born prematurely and ten were born small for gestational age. Screening for myelosuppresion was performed in sixteen neonates (14.7%); two had anemia in umbilical cord blood. All outcomes were comparable to either the general Dutch population or to data from 3 Dutch cohort studies on the use of conventional thiopurines in pregnant IBD patients.

CONCLUSION

In this large case series the use of thioguanine during pregnancy is not associated in excess with adverse maternal or neonatal outcomes.

Decoding the molecular cascade of embryonic-uterine modulators in pregnancy loss of PCOS mother- an "in vivo" study

BACKGROUND

Polycystic ovary syndrome is associated with an increased rate of spontaneous abortion/early pregnancy loss and pups delivered to PCOS animals were abnormal. Currently, assisted reproductive technology has been used to help numerous infertile couples to have their babies. However, there is a low implantation rate after the transfer of embryos. Till now, it could not be concluded whether the reduced pregnancy rates observed were due to abnormal embryos or endometrial modification. Further, transgenic mouse models have been used to find out the molecular deficits behind early pregnancy complications. But, the deletion of crucial genes could lead to systemic deficiencies/embryonic lethality. Also, pregnancy is a complex process with overlapping expression patterns making it challenging to mimic their stage-specific role. Therefore, the motive of the current study was to investigate the probable molecular cascade to decipher the early pregnancy loss in the letrozole-induced PCOS mouse model.

METHODS

PCOS was induced in mice by oral administration of letrozole daily for 21 days. Following, the pregnancy was established and animals were sacrificed on the day 6th of pregnancy. Animals were assessed for early pregnancy loss, hormonal profile, mRNA expression of steroid receptors (Ar, Pr, Esr1/2), decidualization markers (Hox10/11a), adhesion markers (Itgavb3, Itga4b1), matrix metalloproteinases and their endogenous inhibitor (Mmp2/9, Timp1/2) and key mediators of LIF/STAT pathway (Lif, Lifr, gp130, stat3) were analyzed in the embryo implanted region of the uterus. Morphological changes in ovaries and implanted regions of the uterus were assessed.

RESULTS

Mice treated with letrozole demonstrated significant increases in testosterone levels along with a decline in progesterone levels as compared to control animals. PCOS animals also exhibited decreased fertility index and disrupted ovarian and embryo-containing uterus histopathology. Altered gene expression of the steroid receptors and reduced expression of Hox10a, integrins, Mmp9, Timp1/3, Gp130 & Stat3 was observed in the implanted region of the uterus of PCOS animals.

CONCLUSION

Our results reveal that majority of the molecular markers alteration in the establishment of early pregnancy could be due to the aberrant progesterone signaling in the embryonic-uterine tissue of PCOS animals, which further translates into poor fetal outcomes as observed in the current study and in several IVF patients.

The psychological status mediates the effect of indoor air pollution on recurrent spontaneous abortion

BACKGROUND

Indoor air pollution (IAP) exposure and psychological status have been recognized as important risk factors for adverse pregnancy outcomes, but their mediating effects on recurrent spontaneous abortion (RSA) have not been analyzed. Therefore, the purpose of this study is to explore the association between IAP and RSA and to examine the mediating effect of psychological status on their association.

METHODS

This study included 830 RSA cases and 2156 controls in Gansu province, China. The Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) questionnaires were used to collect information on participants' psychological status. The IAP exposure was collected by the survey on cooking fuel use, kitchen ventilation characteristics, cooking styles, and indoor smoking, etc. Multivariable logistic regression was used to examine the associations between IAP exposure and RSA. The mediation analysis was used to evaluate the mediation effects of IAP and psychological status on RSA while controlling for confounding.

RESULTS

Among these cases, 16.87% cooked with unclean cooking fuel (UCF) and 37.00% lacked cooking ventilation, which was much higher than the controls. Active smoking and the use of UCF were associated with RSA, with an odds ratio (OR) of 3.374 [95% confidence interval (CI): 1.510-7.541] and 1.822 (95% CI: 1.328-2.500), respectively. We found that the use of a range hood was a protective factor for RSA, with an OR of 0.590 (95% CI: 0.463-0.752). There was a significant mediation effect of depression on the association between IAP and RSA, which accounted for 5.61%-9.22% of the total effect of IAP on RSA.

CONCLUSION

The IAP may be an important risk factor for RSA, which may be intensified by the poor psychological status, and the use of ventilation equipment when cooking is a protective factor for RSA.

Congenital anomalies and spontaneous abortion in mice resulting from the use of escitalopram

CONTEXT

Escitalopram (ESC) use during pregnancy has not been associated with teratogenic effects in fetuses.

AIMS

To investigate whether ESC administered during pregnancy in mice induces maternal toxicity and teratogenicity in offspring.

METHODS

Treated mice groups G1 and control G0 (n =15 per group). Administration of ESC (G1) and saline solution (G0) during pregnancy and euthanasia on the 18thday. Pregnant female mice were treated with ESC (20mg/kg, via gavage) or saline solution (control group) from the 5th to the 17thday of gestation, when implantation was consolidated. During intraembryonic development until the day before delivery, the drug had an influence on the development of alterations from its maintenance in the uterine environment and its development to the disturbance causing skeletal or visceral malformations.

KEY RESULTS

The intrauterine development parameters that were altered by ESC treatment were: number of resorptions (G0: [0.93±0.24]); G1: [3.33±0.51]), post-implantation loss (G0: [3.95±1.34], G1: [13.75±3.62]) and reduced fetal viability: [97.30±1.00]; G1: [81.09±6.22]). Regarding fetal formation, the treated group had visceral malformations with a significant frequency: cleft palate (G0: [1.0%], G1: [11.86%]) and reduced kidneys (G0: [0%]; G1: [10.17%]). Regarding skeletal malformations, a higher frequency was observed in the following parameters: incomplete supraoccipital ossification (G0: [0%], G1: [15.25]), absence of ribs (G0: [0%], G1 (G0: [0%], G1 [15.25%]) and absence of one or more of the foot phalanges (G0: [1.0%]; 64%]).

CONCLUSION

Results indicate that ESC is an embryotoxic and teratogenic drug.

IMPLICATIONS

Until further studies are performed, greater caution is necessary in prescribing the drug to pregnant women.

Drinking water nitrate and risk of pregnancy loss: a nationwide cohort study

BACKGROUND

Nitrate contamination is seen in drinking water worldwide. Nitrate may pass the placental barrier. Despite suggestive evidence of fetal harm, the potential association between nitrate exposure from drinking water and pregnancy loss remains to be studied. We aimed to investigate if nitrate in drinking water was associated with the risk of pregnancy loss.

METHODS

We conducted a nationwide cohort study of 100,410 pregnancies (enrolled around gestational week 11) in the Danish National Birth Cohort (DNBC) during 1996-2002. Spontaneous pregnancy losses before gestational week 22 were ascertained from the Danish National Patient Registry and DNBC pregnancy interviews. Using the national drinking water quality-monitoring database Jupiter, we estimated the individual and time-specific nitrate exposure by linking geocoded maternal residential addresses with water supply areas. The nitrate exposure was analyzed in spline models using a log-transformed continuous level or classified into five categories. We used Cox proportional hazards models to estimate associations between nitrate and pregnancy loss and used gestational age (days) as the time scale, adjusting for demographic, health, and lifestyle variables.

RESULTS

No consistent associations were found when investigating the exposure as a categorical variable and null findings were also found in trimester specific analyses. In the spline model using the continuous exposure variable, a modestly increased hazard of pregnancy loss was observed for the first trimester at nitrate exposures between 1 and 10 mg/L, with the highest. adjusted hazard ratio at 5 mg/L of nitrate of 1.16 (95% CI: 1.01, 1.34). This trend was attenuated in the higher exposure ranges.

CONCLUSION

No association was seen between drinking water nitrate and the risk of pregnancy loss when investigating the exposure as a categorical variable. When we modelled the exposure as a continuous variable, a dose-dependent association was found between drinking water nitrate exposure in the first trimester and the risk of pregnancy loss. Very early pregnancy losses were not considered in this study, and whether survival bias influenced the results should be further explored.

Levels and health risks of urinary phthalate metabolites and the association between phthalate exposure and unexplained recurrent spontaneous abortion: a large case-control study from China

Phthalate acid esters (PAEs) are environmental endocrine disruptors that can interfere with endocrine processes and cause adverse reproductive outcomes. The link between PAE exposure and unexplained recurrent spontaneous abortion (URSA) remains unknown. In this study, nine urinary metabolites of PAEs (mPAEs) were measured in 594 URSA cases and 569 healthy controls. The measured mPAEs were ubiquitously detected and present at higher levels (median: 203 ng/mL) in the URSA cases than in the controls (median: 161 ng/mL). Multiple logistic regression analysis showed that URSA was associated with higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), mono (2-ethylhexyl) phthalate (mEHP), and mono-ethyl phthalate (mEP) and lower concentrations of mono-isobutyl phthalate (miBP). Moreover, a quantile-based g-computation (QGC) model revealed a positive association between mPAEs mixture and URSA. The URSA cases showed significantly higher concentrations of di-(2-ethylhexyl) phthalate (DEHP) than the controls. This was consistent with the health risk assessment, which suggested that DEHP is the main contributors to potential non-carcinogenic risk. DEHP accounted for over 80% of total risk. The large case-control study results suggest that PAE exposure may increase the risk of URSA, and that policy-makers and public health experts should pay more attention to DEHP exposure.

Prenatal exposure to ambient air pollution and adverse birth outcomes: An umbrella review of 36 systematic reviews and meta-analyses

Multiple systematic reviews and meta-analyses linked prenatal exposure to ambient air pollutants to adverse birth outcomes with mixed findings, including results indicating positive, negative, and null associations across the pregnancy periods. The objective of this study was to systematically summarise systematic reviews and meta-analyses on air pollutants and birth outcomes to assess the overall epidemiological evidence. Systematic reviews with/without meta-analyses on the association between air pollutants (NO₂, CO, O₃, SO₂, PM_2.5, and PM₁₀) and birth outcomes (preterm birth; stillbirth; spontaneous abortion; birth weight; low birth weight, LBW; small-for-gestational-age) up to March 30, 2022 were included. We searched PubMed, CINAHL, Scopus, Medline, Embase, and the Web of Science Core Collection, systematic reviews repositories, grey literature databases, internet search engines, and references of included studies. The consistency in the directions of the effect estimates was classified as more consistent positive or negative, less consistent positive or negative, unclear, and consistently null. Next, the confidence in the direction was rated as either convincing, probable, limited-suggestive, or limited non-conclusive evidence. Final synthesis included 36 systematic reviews (21 with and 15 without meta-analyses) that contained 295 distinct primary studies. PM_2.5 showed more consistent positive associations than other pollutants. The positive exposure-outcome associations based on the entire pregnancy period were more consistent than trimester-specific exposure averages. For whole pregnancy exposure, a more consistent positive association was found for PM_2.5 and birth weight reductions, particulate matter and spontaneous abortion, and SO₂ and LBW. Other exposure-outcome associations mostly showed less consistent positive associations and few unclear directions of associations. Almost all associations showed probable evidence. The available evidence indicates plausible causal effects of criteria air pollutants on birth outcomes. To strengthen the evidence, more high-quality studies are required, particularly from understudied settings, such as low-and-middle-income countries. However, the current evidence may warrant the adoption of the precautionary principle.

Association of emerging and legacy per- and polyfluoroalkyl substances with unexplained recurrent spontaneous abortion

Emerging per- and polyfluoroalkyl substances (PFAS) alternatives are increasingly used in daily life. Although legacy PFAS have been associated with miscarriage in previous studies, it remains unknown whether exposure to emerging and legacy PFAS has any impact on the risk of unexplained recurrent spontaneous abortion (URSA). We conducted a case-control study with 464 URSA cases who had at least 2 unexplained miscarriages and 440 normal controls who had at least one normal livebirth. Concentrations of 21 PFAS in plasma, including three emerging PFAS alternatives, eight linear and branched PFAS isomers, four short-chain PFAS, and six legacy PFAS, were measured by ultra-performance liquid chromatography coupled with a tandem mass spectrometry (UPLC-MS/MS). Multiple logistic regression was applied to evaluate the relationship between PFAS and URSA risk. Perfluorooctanoic acid (PFOA, median: 6.18 ng/mL), perfluorooctane sulfonate (PFOS, median: 4.10 ng/mL), and 6:2 chlorinated perfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA, median: 2.27 ng/mL) were the predominant PFAS in the controls. Exposure to 6:2 Cl-PFESA [adjusted odds ratio (aOR) = 1.18 (95% CI: 1.00, 1.39)] and hexafluoropropylene oxide dimer acid (HFPO-DA) [aOR = 1.35 (95% CI: 1.15, 1.59)] were significantly associated with increased risks of URSA. Women with older age (>30 years old) had a stronger association between PFAS and URSA. Our results suggest that emerging PFAS alternatives may be an important risk factor for URSA.

Medical methods for first trimester abortion

BACKGROUND

Medical abortion became an alternative method of pregnancy termination following the development of prostaglandins and antiprogesterone in the 1970s and 1980s. Recently, synthesis inhibitors of oestrogen (such as letrozole) have also been used to enhance efficacy. The most widely researched drugs are prostaglandins (such as misoprostol, which has a strong uterotonic effect), mifepristone, mifepristone with prostaglandins, and letrozole with prostaglandins. More evidence is needed to identify the best dosage, regimen, and route of administration to optimise patient outcomes. This is an update of a review last published in 2011.

OBJECTIVES

To compare the effectiveness and side effects of different medical methods for first trimester abortion.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Global Health, and LILACs on 28 February 2021. We also searched Clinicaltrials.gov and the World Health Organization's (WHO) International Clinical Trials Registry Platform, and reference lists of retrieved papers.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that compared different medical methods for abortion before the 12th week of gestation. The primary outcome is failure to achieve complete abortion. Secondary outcomes are mortality, surgical evacuation, ongoing pregnancy at follow-up, time until passing of conceptus, blood transfusion, side effects and women's dissatisfaction with the method.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected and evaluated studies for inclusion, and assessed the risk of bias. We processed data using Review Manager 5 software. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 99 studies in the review (58 from the original review and 41 new studies). 1. Combined regimen mifepristone/prostaglandin Mifepristone dose: high-dose (600 mg) compared to low-dose (200 mg) mifepristone probably has similar effectiveness in achieving complete abortion (RR 1.07, 95% CI 0.87 to 1.33; I2 = 0%; 4 RCTs, 3494 women; moderate-certainty evidence). Prostaglandin dose: 800 µg misoprostol probably reduces abortion failure compared to 400 µg (RR 0.63, 95% CI 0.51 to 0.78; I2= 0%; 3 RCTs, 4424 women; moderate-certainty evidence). Prostaglandin timing: misoprostol administered on day one probably achieves more success on complete abortion than on day three (RR 1.94, 95% CI 1.05 to 3.58; 1489 women; 1 RCT; moderate-certainty evidence). Administration strategy: there may be no difference in failure of complete abortion with self-administration at home compared with hospital administration (RR 1.63, 95% CI 0.68 to 3.94; I2 = 84%; 2263 women; 4 RCTs; low-certainty evidence), but failure may be higher when administered by nurses in hospital compared to by doctors in hospital (RR 2.69, 95% CI 1.39 to 5.22; I2 = 66%; 3 RCTs, 3056 women; low-certainty evidence). Administration route: oral misoprostol probably leads to more failures than the vaginal route (RR 2.38, 95% CI 1.46 to 3.87; I2 = 39%; 3 RCTs, 1704 women; moderate-certainty evidence) and may be associated with more frequent side effects such as nausea (RR 1.14, 95% CI 1.03 to 1.26; I2 = 0%; 2 RCTs, 1380 women; low-certainty evidence) and diarrhoea (RR 1.80 95% CI 1.49 to 2.17; I2 = 0%; 2 RCTs, 1379 women). Compared with the vaginal route, complete abortion failure is probably lower with sublingual (RR 0.68, 95% CI 0.22 to 2.11; I2 = 59%; 2 RCTs, 3229 women; moderate-certainty evidence) and may be lower with buccal administration (RR 0.71, 95% CI 0.34 to 1.46; I2 = 0%; 2 RCTs, 479 women; low-certainty evidence), but sublingual or buccal routes may lead to more side effects. Women may experience more vomiting with sublingual compared to buccal administration (RR 1.33, 95% CI 1.01 to 1.77; low-certainty evidence). 2. Mifepristone alone versus combined regimen The efficacy of mifepristone alone in achieving complete abortion compared to combined mifepristone/prostaglandin up to 12 weeks is unclear (RR of failure 3.25, 95% CI 0.81 to 13.09; I2 = 83%; 3 RCTs, 273 women; very low-certainty evidence). 3. Prostaglandin alone versus combined regimen Nineteen studies compared prostaglandin alone to a combined regimen (prostaglandin combined with mifepristone, letrozole, estradiol valerate, tamoxifen, or methotrexate). Compared to any of the combination regimens, misoprostol alone may increase the risk for failure to achieve complete abortion (RR of failure 2.39, 95% CI 1.89 to 3.02; I2 = 64%; 18 RCTs, 3471 women; low-certainty evidence), and with more diarrhoea. 4. Prostaglandin alone (route of administration) Oral misoprostol alone may lead to more failures in complete abortion than the vaginal route (RR 3.68, 95% CI 1.56 to 8.71, 2 RCTs, 216 women; low-certainty evidence). Failure to achieve complete abortion may be slightly reduced with sublingual compared with vaginal (RR 0.69, 95% CI 0.37 to 1.28; I2 = 87%; 5 RCTs, 2705 women; low-certainty evidence) and oral administration (RR 0.58, 95% CI 0.11 to 2.99; I2 = 66%; 2 RCTs, 173 women). Failure to achieve complete abortion may be similar or slightly higher with sublingual administration compared to buccal administration (RR 1.11, 95% CI 0.71 to 1.74; 1 study, 401 women).

AUTHORS' CONCLUSIONS

Safe and effective medical abortion methods are available. Combined regimens (prostaglandin combined with mifepristone, letrozole, estradiol valerate, tamoxifen, or methotrexate) may be more effective than single agents (prostaglandin alone or mifepristone alone). In the combined regimen, the dose of mifepristone can probably be lowered to 200 mg without significantly decreasing effectiveness. Vaginal misoprostol is probably more effective than oral administration, and may have fewer side effects than sublingual or buccal. Some results are limited by the small numbers of participants on which they are based. Almost all studies were conducted in settings with good access to emergency services, which may limit the generalisability of these results.

Evaluating the Effects of BPA and TBBPA Exposure on Pregnancy Loss and Maternal-Fetal Immune Cells in Mice

BACKGROUND

Bisphenol A (BPA) exposure has been linked to miscarriages and pregnancy complications in humans. In contrast, the potential reproductive toxicity of BPA analogs, including tetrabromobisphenol A (TBBPA), is understudied. Furthermore, although environmental exposure has been linked to altered immune mediators, the effects of BPA and TBBPA on maternal-fetal immune tolerance during pregnancy have not been studied. The present study investigated whether exposure resulted in higher rates of pregnancy loss in mice, lower number of regulatory T cells (Tregs), and lower indoleamine 2,3 deoxygenase 1 (Ido1) expression, which provided evidence for mechanisms related to immune tolerance in pregnancy.

OBJECTIVES

The purpose of this investigation was to characterize the effects of BPA and TBBPA exposure on pregnancy loss in mice and to study the percentage and number of Tregs and Ido1 expression and DNA methylation.

METHODS

Analysis of fetal resorption and quantification of maternal and fetal immune cells by flow cytometry were performed in allogeneic and syngeneic pregnancies. Ido1 mRNA and protein expression, and DNA methylation in placentas from control and BPA- and TBBPA-exposed mice were analyzed using real-time quantitative polymerase chain reaction, immunofluorescence, and bisulfite sequencing analyses.

RESULTS

BPA and TBBPA exposure resulted in higher rates of hemorrhaging in early allogeneic, but not syngeneic, conceptuses. In allogeneic pregnancies, BPA and TBBPA exposure was associated with higher fetal resorption rates and lower maternal Treg number. Importantly, these differences were associated with lower IDO1 protein expression in trophoblast giant cells and higher mean percentage Ido1 DNA methylation in embryonic day 9.5 placentas from BPA- and TBBPA-exposed mice.

DISCUSSION

BPA- and TBBPA-induced pregnancy loss in mice was associated with perturbed IDO1-dependent maternal immune tolerance. https://doi.org/10.1289/EHP10640.

The correlation between chronic exposure to particulate matter and spontaneous abortion: A meta-analysis

BACKGROUND

Spontaneous abortion (SAB) brings serious physical and psychological sequelae to women and their families. Though a growing body of individual studies have suggested the possible linkage between chronic particulate matter (PM) exposure and risks of SAB, the provided results were rather contradictory. We therefore performed an evidence-based meta-analysis.

METHODS

We systematically searched the PubMed, EMBASE and Web of Science databases for available studies published before February 1, 2021 which reported associations between PM exposure and SAB. Corresponding models were applied to combine relative risks (RRs) and their confidence intervals (CIs) from eligible studies according to heterogeneity test. The GRADEpro app was used to evaluate the certainty of evidence. Sensitivity analyses and a publication bias assessment were also utilized to determine the stability of results.

RESULTS

Of the initial 2358 citations, 6 papers examining the chronic effects of PM exposure were deemed eligible and a total population of approximately 723,000 was observed. Pooled RR for SAB risks associated with a 10 μg/m³ increase in fine particulate matter (PM_2.5) and particulate matter ≤ 10 μm in aerodynamic diameter (PM₁₀) were 1.20 (95%CI: 1.01-1.40) and 1.09 (95%CI: 1.02-1.15), respectively. The GRADE results of PM_2.5 and PM₁₀ were both categorized as "moderate" certainty evidence.

CONCLUSION

Our findings revealed a significant increase of SAB hazards related with maternal PM exposure, and this study may therefore provide new evidence for personal protection to improve reproductive health.

Low Endogenous LH on the COS Initiation Day of a GnRH-Agonist Regimen Increases the Risk of Early Pregnancy Loss and Adverse ART Outcomes

OBJECTIVE

To assess the impact of serum luteinizing hormone (LH) levels on the day of initiation of controlled ovarian stimulation (COS) after pituitary suppression on early pregnancy loss and assisted reproductive technology (ART) outcomes.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated hospital.

PATIENTS

A total of 9540 normogonadotrophic patients were treated with a GnRH agonist for in vitro fertilization (IVF). Based on the serum concentration of LH on the COS initiation day, patients were divided into low (<1 mIU/mL, n=2838), medium (1-1.49 mIU/mL, n=3357), or high (≥1.5 mIU/mL, n=3345) LH groups and received either fresh embryo transfer (ET) or frozen ET (women with high ovarian response, insufficient endometrial thickness, or requesting frozen ET). A total of 6279 cycles were fresh ET (1960, 2222, and 2097 in the low, medium, and high LH groups, respectively).

INTERVENTIONS

During IVF/ICSI, a GnRH agonist was used to suppress pituitary function in the midluteal phase or follicular phase, and then gonadotropin was used to induce COS.

MAIN OUTCOME MEASURES

The early pregnancy loss rate (ePLR) and live-birth rate (LBR) for fresh ET, as well as the cumulative ePLR and LBR for the entire ovarian stimulation cycle, were compared.

RESULTS

In the fresh ET cycles, the high, medium and low LH groups had an ePLR of 8.6%, 11.9% and 12.5%, respectively, and LBR of 42.1%, 37.9% and 37.5%, respectively. There were no significant differences in terms of clinical pregnancy rate (CPR), late pregnancy loss rate (lPLR), and ectopic pregnancy rate (EPR) among the three LH groups. For the entire ovarian stimulation cycle, the high LH group had a greater number of retrieved oocytes compared with the low and medium LH groups. Among the groups of high, medium and low LH, the cumulative CPR were 72.8%, 69.8% and 68.8%, respectively, and the cumulative LBR were 63.4%, 60.4% and 58.5%, respectively. There were no significant differences in the cumulative ePLR, lPLR, or EPR. After multivariable logistic regression, compared with the high LH group, the adjusted odds ratio of early pregnancy loss in the low and medium LH group were 1.429 (1.065-1.919, P = 0.018) and 1.389 (1.041-1.853, P = 0.026).

CONCLUSIONS

After pituitary suppression by a GnRH-agonist during IVF, a low LH level (<1.5 mIU/mL) on the COS initiation day was associated with adverse ART outcomes-including fewer oocytes, higher ePLR and lower LBR in fresh ET-and lower cumulative CPR and LBR in the entire ovarian-stimulation cycle. And LH on the COS initiation day was an independent factor affecting ePLR after multivariate regression.

A multi-pollutant assessment of preconception persistent endocrine disrupting chemicals and incident pregnancy loss

BACKGROUND

A few endocrine disrupting chemicals (EDCs) have been associated with pregnancy loss often as reported by women, though there has been no study of EDC mixtures and pregnancy loss in keeping with the nature of human exposure.

OBJECTIVES

To investigate preconception exposure to a mixture of EDCs to identify important drivers and inform multi-pollutant models of EDCs in relation to incident human gonadrophin chorionic (hCG) pregnancy loss.

METHODS

A cohort of 501 couples were recruited from the general population and prospectively followed until a hCG-confirmed pregnancy or 12 months of trying to become pregnant. Pregnant (n = 344; 69%) women were followed daily through seven weeks post-conception then monthly until delivery. Loss was defined as conversion to negative pregnancy test or a clinical diagnosis. Preconception exposure assessment of EDCs included sixty-three serum chemicals and three blood metals. EDCs were measured using isotope dilution gas chromatography-high resolution mass spectrometry or high-performance liquid chromatography-tandem mass spectrometry, and inductively coupled plasma-mass spectrometry, respectively. Using elastic net variable selection to identify important factors from the exposure mixture, EDC levels and covariates were then included in Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of time-to-pregnancy loss in multi-pollutant models.

RESULTS

Incidence of hCG pregnancy loss was 28%. Nine EDCs of the sixty-six chemical mixture were associated with pregnancy loss; HRs were elevated for polychlorinated biphenyl 194, 2-(N-methyl-perfluorooctane sulfonamido) acetate, polybrominated diphenyl ether 28, and cadmium, even in sensitivity models adjusting for male partners' EDC concentrations. In final multivariable multi-pollutant Cox proportional hazard models, female partners'polybrominated diphenyl ether 28 (aHR = 1.16, 95% CI: 1.02, 1.31) and cadmium (aHR = 1.23, 95% CI: 1.07, 1.40) remained associated with hCG pregnancy loss. Female partners' preconception serum polychlorinated biphenyl 194 and 2-(N-methyl-perfluorooctane sulfonamido) acetate concentrations were consistently inversely associated with loss [(aHR = 0.72, 95% CI: 0.56, 0.92) and (aHR = 0.79, 95% CI: 0.65, 0.95), respectively].

CONCLUSION

Assessing exposure to a mixture of 66 persistent EDCs, females' preconception concentrations of polybrominated diphenyl ether 28 and cadmium were positively associated with incident hCG pregnancy loss in a cohort of couples from the general population trying for pregnancy.

Association of Inadvertent 9-Valent Human Papillomavirus Vaccine in Pregnancy With Spontaneous Abortion and Adverse Birth Outcomes

IMPORTANCE

The 9-valent human papillomavirus (9vHPV) vaccine is recommended for individuals through age 26 years and may be administered to women up to age 45 years. Data on 9vHPV vaccine exposures during pregnancy are limited.

OBJECTIVE

To evaluate the associations between 9vHPV vaccine exposures during pregnancy or peripregnancy and selected pregnancy and birth outcomes (spontaneous abortion [SAB], preterm birth, small-for-gestational age [SGA] birth, and major structural birth defect).

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed data from 7 participating health systems in the Vaccine Safety Datalink. The cohort comprised pregnancies among girls and women aged 12 to 28 years that ended between October 26, 2015, and November 15, 2018. Singleton pregnancies that ended in a live birth, stillbirth, or SAB were included.

EXPOSURES

Vaccine exposure windows were distal (9vHPV or 4vHPV vaccine administered from 22 to 16 weeks before last menstrual period [LMP]), peripregnancy (9vHPV vaccine administered from 42 days before LMP until LMP), and during pregnancy (9vHPV vaccine administered from LMP to 19 completed weeks' gestation). Primary comparisons were (1) girls and women with 9vHPV vaccine exposures during pregnancy vs those with 4vHPV or 9vHPV distal vaccine exposures, (2) girls and women with vaccine exposures peripregnancy vs those with 4vHPV or 9vHPV distal vaccine exposures, and (3) girls and women with 9vHPV vaccine exposures during pregnancy or peripregnancy vs those with 4vHPV or 9vHPV distal vaccine exposure.

MAIN OUTCOMES AND MEASURES

Spontaneous abortions were confirmed based on medical record review and adjudication. Preterm and SGA births were identified from electronic health record and birth data. Major structural birth defects were based on diagnostic codes using a validated algorithm. Inverse probability weighting was used to balance the covariates. Time-dependent covariate Cox proportional hazards regression models and Poisson regression were used to estimate the associations between 9vHPV vaccine exposures and pregnancy and birth outcomes.

RESULTS

The final cohort included 1493 pregnancies among girls and women with a mean (SD) maternal age of 23.9 (2.9) years. Of these pregnancies, 445 (29.8%) had exposures to the 9vHPV vaccine during pregnancy, 496 (33.2%) had exposures to the 9vHPV vaccine peripregnancy, and 552 (37.0%) had 4vHPV or 9vHPV distal vaccine exposures. The 9vHPV vaccine administered during pregnancy was not associated with increased risk for SAB (hazard ratio, 1.12; 95% CI, 0.66-1.93) compared with distal vaccine exposures. Findings were similar for 9vHPV vaccine exposures peripregnancy (relative risk [RR], 0.72; 95% CI, 0.42-1.24). Among live births (n = 1409), 9vHPV vaccine exposures during pregnancy were not associated with increased risks for preterm birth (RR, 0.73; 95% CI, 0.44-1.20) or SGA birth (RR, 1.31; 95% CI, 0.78-2.20). Results were similar regarding the association between 9vHPV vaccine exposures peripregnancy and preterm birth (RR, 0.72; 95% CI, 0.45-1.17) and SGA birth (RR, 1.10; 95% CI, 0.65-1.88). Birth defects were rare in all exposure groups, occurring in about 1% of live births with available infant data.

CONCLUSIONS AND RELEVANCE

This study found that 9vHPV vaccine exposures during or around the time of pregnancy were uncommon and not associated with SABs or selected adverse birth outcomes. These findings can inform counseling for inadvertent 9vHPV vaccine exposures.

Exposure to organophosphate flame esters during early pregnancy and risk of spontaneous abortion: A case-control study

Prenatal exposure to organophosphate flame retardants (OPFRs) has been associated with adverse pregnancy outcomes including low birth weight and preterm birth. However, no study has addressed the impacts of OPFRs exposure on spontaneous abortion (SAB) and fetal chromosome abnormalities. We examined whether prenatal exposure to OPFRs was associated with increased risk of SAB and fetal chromosome abnormalities. A total of 272 pregnant women, including 136 SAB cases and 136 healthy controls, were enrolled in this case-control study. Urinary concentrations of 3 OPFRs metabolites (diphenyl phosphate (DPHP), bis (1,3-dichloro-2-propyl) phosphate (BDCIPP) and bis (1-chloro-2-propyl) phosphate (BCIPP)) were measured using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). More than 70% of the urine samples detected quantifiable levels of 3 OPFRs metabolites. Concentrations of BCIPP were significantly higher in SAB cases than in healthy controls. Higher urinary BCIPP levels were associated with increased risk of SAB. Per unit increase in ln-transformed BCIPP concentrations was associated with 103% (OR = 2.03, 95% CI, 1.57, 2.63) increase in the odds of SAB. While higher BDCIPP levels were associated with increased risk of fetal chromosome abnormalities and the corresponding OR associated with a unit increase in ln-transformed BDCIPP concentrations were 2.34 (95% CI, 1.14, 4.81). Our results suggested the potential developmental toxicity and teratogenicity of some OPFRs.

Spontaneous abortion in women occupationally exposed to inhalational anesthetics: a critical systematic review

Occupational exposure to inhalational anesthetics has been associated with health problems, including reproductive issues. Considering the scarcity and outdated nature of reviews concerning this relevant topic, which has implications for indoor pollution/environmental science/public health, this critical review aimed to systematically evaluate whether exposure to inhalational anesthetics is associated with abortion. Seven databases were searched with no language or year restrictions. Of the 3881 search results, 18 observational studies were included. Some studies demonstrated a significant association between occupational exposure to inhalational anesthetics and spontaneous abortion, especially among professionals who work for longer periods and/or in an environment without gas scavenging/ventilation systems, which may favor the occurrence of abortion in this population. Due to considerable heterogeneity and limitations, it cannot be concluded whether an association exists between occupational exposure to anesthetics and the occurrence of abortion. However, more well-designed studies should be performed, especially in less economically developed countries that do not have access to quality anesthetic gas scavenging/ventilation systems, thereby bringing this issue into sharp focus. This review highlights the need for scientific knowledge in this area and the extensive use of scavenging equipment and in the workplace to minimize exposure and reduce the risk of abortion.

Premature senescence of placental decidua cells as a possible cause of miscarriage produced by mycophenolic acid

BACKGROUND

Successful pregnancy is supported by a healthy maternal-fetal interface (i.e., the decidual tissues) which holds the conceptus and safeguards it against stressors from the beginning of pregnancy. Any disturbance of this interface can presumably lead to the loss of pregnancy. The use of the immunosuppressive drug mycophenolic acid (MPA) should be discontinued in pregnancy given its abortive and embryotoxic effects. Direct teratogenic effects have been observed in mammalian embryos cultured in MPA, but the underlying mechanisms of abortion by MPA are less understood.

METHODS

Decidual stromal cells isolated from human placentas are cultured in the presence of clinically relevant doses of MPA. Data regarding the effects of MPA on the proliferation and viability of decidua cultures are first analysed and then, molecular pathways contributing to these effects are unravelled.

RESULTS

MPA treatment of decidual stromal cells results in loss of proliferation capacity and a decrease in the viability of decidua cultures. The molecular pathways involved in the effects of MPA on decidual stromal cells are a reduction in pre-rRNA synthesis and subsequent disruption of the nucleolus. The nucleolar stress stabilizes p53, which in turn, leads to a p21-mediated cell cycle arrest in late S and G2 phases, preventing the progression of the decidua cells into the mitosis. Furthermore, MPA does not induce apoptosis but activate mechanisms of autophagy and senescence in decidual stromal cells.

CONCLUSION

The irreversible growth arrest of decidua cells, whose role in the maintenance of the pregnancy microenvironment is known, may be one cause of miscarriage in MPA treated pregnant women.

Estimation of pregnancy losses attributable to exposure to ambient fine particles in south Asia: an epidemiological case-control study

BACKGROUND

Maternal exposure to ambient particulate matter (PM_2·5) is associated with pregnancy loss (ie, stillbirth and miscarriage). South Asia has the highest burden of pregnancy loss globally and is one of the most PM_2·5 polluted regions in the world. However, knowledge of the relevant exposure-response function for mothers is insufficient.

METHODS

In this epidemiological case-control study, we collected data from Demographic and Health Surveys from India, Pakistan, and Bangladesh for the period 1998-2016 for women who reported at least one pregnancy loss and one or more livebirths. We assessed ambient exposure during gestation with satellite-based PM_2·5 measurements for the period. To derive the exposure-response function, we did a self-compared case-control study in which each case of pregnancy loss was compared with a successful livebirth control or controls by the same mother. Using the estimated exposure-response function, we quantified pregnancy losses attributable to PM_2·5 in the region for the period 2000-16 using a standard risk assessment approach.

FINDINGS

We assessed data for 34 197 mothers, who had at least one pregnancy loss and one or more livebirth, of whom 26 282 (76·9%) were from India, 4228 (12·4%) were from Pakistan, and 3687 (10·8%) were from Bangladesh. The 34 197 cases of pregnancy loss were matched with 76 282 livebirth controls. The mean level of PM_2·5 exposure was 56·00 μg/m³ (SD 30·82) for cases and 54·57 μg/m³ (31·73) for controls. After adjustment for maternal age, non-linear terms for temperature and humidity, seasonal variation, and long-term trends, each 10 μg/m³ increment in PM_2·5 was associated with an odds ratio for pregnancy loss of 1·03 (95% CI 1·02-1·05). According to the estimated non-linear exposure-response function by age and urban residence versus rural residence, for the period 2000-16, an estimated 349 681 (95% CI 152 932-489 493) pregnancy losses per year were attributed to ambient air exposure of more than 40 μg/m³ (the annual PM_2·5 standard of India), accounting for 7·1% (95% CI 3·3-31·2) of the total annual pregnancy loss burden in south Asia for this period. However, our estimates could be biased because of the limitations of the data (eg, misclassification of induced and spontaneous pregnancy losses).

INTERPRETATION

Our findings add to epidemiological evidence of the association between pregnancy loss and PM_2·5. Suboptimal air quality contributes to a considerable fraction of total pregnancy loss in south Asia. Controlling PM_2·5 pollution will promote maternal health in south Asia.

FUNDING

Chinese Natural Science Foundation and Ministry of Science and Technology of China.