Risk of ischemic placental disease is increased following in vitro fertilization with oocyte donation: a retrospective cohort study

Risks of Placental Abruption and Preterm Delivery in Patients Undergoing Assisted Reproduction

Importance

Patients using assisted reproductive technology (ART) may need additional counseling about the increased risks of placental abruption and preterm delivery. Further investigation into the potential additive risk of ART and placental abruption is needed.

Objective

To ascertain the risk of placental abruption in patients who conceived with ART and to evaluate if placental abruption and ART conception are associated with an increased risk of preterm delivery (<37 weeks' gestation) over and above the risks conferred by each factor alone.

Design, Setting, and Participants

This cross-sectional study used data from the National Inpatient Sample, which includes data from all-payer hospital inpatient discharges from 48 states across the US. Participants included women aged 15 to 54 years who delivered from 2000 through 2019. Data were analyzed from January 17 to April 18, 2024.

Exposures

Pregnancies conceived with ART.

Main Outcomes and Measures

Risks of placental abruption and preterm delivery in ART conception compared with spontaneous conceptions. Associations were expressed as odds ratios (ORs) and 95% CIs derived from weighted logistic regression models before and after adjusting for confounders. The relative excess risk due to interaction (RERI) of the risk of preterm delivery based on ART conception and placental abruption was also assessed.

Results

Of 78 901 058 deliveries, the mean (SD) maternal age was 27.9 (6.0) years, and 9 212 117 patients (11.7%) were Black individuals, 14 878 539 (18.9%) were Hispanic individuals, 34 899 594 (44.2%) were White individuals, and 19 910 807 (25.2%) were individuals of other races and ethnicities. Of the total hospital deliveries, 98.2% were singleton pregnancies, 68.8% were vaginal deliveries, and 52.1% were covered by private insurance. The risks of placental abruption among spontaneous and ART conceptions were 11 and 17 per 1000 hospital discharges, respectively. After adjusting for confounders, the adjusted OR (AOR) of placental abruption was 1.42 (95% CI, 1.34-1.51) in ART pregnancies compared with spontaneous conceptions, with increased odds in White women (AOR, 1.42; 95% CI, 1.31-1.53) compared with Black women (AOR, 1.16; 95% CI, 0.93-1.44). The odds of preterm delivery were significantly higher in pregnancies conceived by ART compared with spontaneous conceptions (AOR, 1.46; 95% CI, 1.42-1.51). The risk of preterm delivery increased when patients had both ART conception and placental abruption (RERI, 2.0; 95% CI, 0.5-3.5).

Conclusions and Relevance

In this cross-sectional study, patients who conceived using ART and developed placental abruption had a greater risk of preterm delivery compared with spontaneous conception without placental abruption. These findings have implications for counseling patients who seek infertility treatment and obstetrical management of ART pregnancies.

Pregnancies through oocyte donation. A mini review of pathways involved in placental dysfunction

Pregnancies resulting from assisted reproductive techniques (ART) are increasingly prevalent worldwide. While most pregnancies conceived through in-vitro fertilization (IVF) progress without complications, mounting evidence suggests that these pregnancies are at a heightened risk of adverse perinatal outcomes. Specifically, IVF pregnancies involving oocyte donation have garnered attention due to numerous reports indicating an elevated risk profile for pregnancy-related complications within this subgroup of patients. The precise mechanisms contributing to this increased risk of complications remain incompletely understood. Nonetheless, it is likely that they are mediated by an abnormal immune response at the fetal-maternal interface. Additionally, these outcomes may be influenced by baseline patient characteristics, such as the etiology of infertility, absence of corpus luteum, and variations in endometrial preparation protocols, among other factors. This review aims to succinctly summarize the most widely accepted mechanisms that potentially contribute to the onset of placental dysfunction in pregnancies conceived through oocyte donation.

No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture

STUDY QUESTION

Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception?

SUMMARY ANSWER

There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study.

WHAT IS KNOWN ALREADY

Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions.

STUDY DESIGN, SIZE, DURATION

This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia).

PARTICIPANTS/MATERIALS, SETTING, METHODS

From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer.

LIMITATIONS, REASONS FOR CAUTION

This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables.

WIDER IMPLICATIONS OF THE FINDINGS

Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare.

TRIAL REGISTRATION NUMBER

N/A.

Fetal Growth Velocity according to the Mode of Assisted Conception

INTRODUCTION

Pregnancies conceived through assisted reproductive techniques (ARTs) are on the rise worldwide and have been associated with a higher risk of placental-related disease in the third trimester.

METHODS

A cohort was created of singleton pregnancies after assisted reproduction, admitted at our institution for delivery, between January 2020 and August 2022. Fetal growth velocity from the second trimester to delivery was compared against a gestational-age-matched group of pregnancies spontaneously conceived according to the origin of the selected oocyte (i.e., autologous vs. donated).

RESULTS

125 singleton pregnancies conceived through ART were compared to 315 singleton spontaneous conceptions. Overall, after adjusting for possible confounders, multivariate analysis demonstrated that ART pregnancies had a significantly lower estimated fetal weight (EFW) z-velocity from the second trimester to delivery (adjusted mean difference = -0.002; p = 0.035) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 2.32 [95% CI, 1.15-4.68]). Also, when ART pregnancies were compared according to the type of oocyte, those conceived with donated oocytes showed a significantly lower EFW z-velocity from the second trimester to delivery (adjusted mean difference = -0.008; p = 0.001) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 5.33 [95% CI, 1.34-21.5]).

CONCLUSIONS

Pregnancies achieved through ART exhibit a pattern of lower growth velocity across the third trimester, especially those conceived with donated oocytes. The former represents a sub-group at the highest risk of placental dysfunction that may warrant closer follow-up.

A decrease in endometrial thickness before embryo transfer is not associated with preterm birth and placenta-mediated pregnancy complications

RESEARCH QUESTION

Does a decrease in endometrial thickness (compaction ≥10%) before embryo transfer prognosticate the risk for preterm birth and placenta-mediated pregnancy complications among IVF pregnancies?

DESIGN

Retrospective cohort study at a large private fertility practice. Patients with a singleton live birth after a fresh or frozen embryo transfer between 2016 and 2019 were included. The primary outcome was preterm birth (delivery before 37 weeks gestational age). Secondary outcomes included gestational hypertension, pre-eclampsia, intrauterine growth restriction and placental abruption.

RESULTS

Of the 252 patients that met the study criteria, 122 (48%) demonstrated endometrial compaction (≥10%) and 130 (52%) did not. Age, body mass index (BMI), parity, history of preterm birth or history of pre-existing maternal conditions between the compaction and no-compaction groups were not significantly different. The overall prevalence of placenta-mediated complications across all participants was 25% (n = 62). The number of preterm births between the compaction and no-compaction groups (13% and 6%, respectively, P = 0.09) as well as the prevalence of placenta-mediated complications (29.5% and 20%, respectively, P = 0.08) were not significantly different. Findings for the primary outcome (preterm birth) persisted even after adjustment for potential confounding variables, including maternal age, parity, BMI, embryo score and type of embryo transfer (fresh versus frozen) (adjusted OR 1.86, 95% CI 0.64 to 5.38).

CONCLUSIONS

Endometrial compaction (or decrease in endometrial thickness) before embryo transfer is not associated with preterm birth or placenta-mediated pregnancy complications.

Effects of Different Endometrial Preparation Regimens during IVF on Incidence of Ischemic Placental Disease for FET Cycles

We conducted this retrospective cohort study aiming to compare the different pregnancy outcomes of endometrial preparation regimens on ischemic placental disease in a frozen embryo transfer cycle. The study included a total of 9351 women who had undergone therapy at our single tertiary hospital from January 2015 to July 2020. The women were divided into three groups depending on their endometrial regimens: natural cycle, stimulation cycle, hormone replacement therapy cycle. The data were analyzed after propensity score matching, then we used multiple linear regression to study the relationship between ischemic placental disease and endometrial regimens, adjusted by confounding factors including age, body mass index, and score of propensity score matching. We performed univariate logistic regression, as well as multivariate logistic regression for ischemic placental disease, small for gestational age infant, placental abruption. and pre-eclampsia, respectively, listing the odds ratio and p-values in the table. As a result, risk of ischemic placental disease and small for gestational age infant were detected as higher in stimulation cycles compared to natural cycles before or after adjustment. Hormone replacement therapy cycles conferred a higher risk of pre-eclampsia and preterm delivery compared to natural cycles. No difference was found between stimulation cycles and hormone replacement therapy cycles, regardless of whether they are adjusted or not. In summary, more pharmacological intervention in endometrial preparation was associated with a higher risk of ischemic placental disease related symptoms than natural cycles for endometrial preparation in women undergoing frozen embryo transfer. Our findings supported that minimizing pharmacological interventions during endometrial preparation when conditions permit has positive implications for improving pregnancy outcomes.

PCOS and the risk of pre-eclampsia

RESEARCH QUESTION

What is the association between polycystic ovary syndrome (PCOS) and pre-eclampsia? Data suggest that patients with PCOS are at increased risk of developing pre-eclampsia; however, several studies have not found an independent association between the two.

DESIGN

A retrospective case-control study of singleton deliveries at a tertiary care hospital from 2011 to 2015. Patients with pre-eclampsia (cases) were matched to the next delivery without pre-eclampsia (controls) on gestational age week. Medical history data, a diagnosis or clinical features of PCOS and obstetric data, including pre-eclampsia, were abstracted from the medical record. Groups were compared with the chi-squared test, and conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). OR were adjusted for maternal age at delivery and race/ethnicity.

RESULTS

This study included 435 cases and 435 controls. Cases were more likely to be Black compared with controls. Age, comorbidities, features of PCOS and use of IVF were similar between groups. Patients with pre-eclampsia were not more likely to have PCOS (8.3%) than those without pre-eclampsia (6.2%, adjusted OR 1.40, 95% CI 0.81-2.30). Sensitivity analyses for body mass index and parity suggested an increased pre-eclampsia risk for patients with PCOS and these additional factors, however no group showed a statistically significant association between PCOS and pre-eclampsia.

CONCLUSIONS

In this study, a history of PCOS was not associated with the risk of pre-eclampsia. Further investigation is necessary to determine whether there are subgroups of PCOS patients who are at increased risk of pre-eclampsia.

Association of Early Beta Human Chorionic Gonadotropin With Ischemic Placental Disease in Singleton Pregnancies After In Vitro Fertilization

Objectives: To evaluate whether an initial or two-day percent increase in serum beta-human chorionic gonadotropin (βhCG) is associated with ischemic placental disease (IPD) in singleton pregnancies after autologous or donor IVF.

Study design: This was a secondary analysis of a retrospective cohort study of deliveries linked to IVF cycles at a single academic tertiary hospital and infertility treatment center. We included all patients (≥18 years old) who had a singleton live birth or intrauterine fetal demise (IUFD) resulting from either autologous fresh (n=1,347), autologous frozen (n=454), or donor (n=253) IVF cycles.

Main outcome reassures: The primary outcome was a composite outcome of IPD or IUFD due to placental insufficiency. IPDs included preeclampsia, placental abruption, and small for gestational age (SGA).

Results: Neither initial βhCG nor two-day percent increases in βhCG were associated with an increased risk of IPD for any type of IVF cycle. Initial and two-day percent increases in βhCG were significantly higher when comparing frozen with fresh IVF and donor with autologous IVF (all P≤0.01).

Conclusions: Among singleton autologous and donor IVF cycles, the initial and two-day percent increase in serum βhCG were not associated with IPD or its components. However, significant βhCG differences existed by cycle type and oocyte source.

Multifoetal gestations mediate the effect of in vitro fertilisation (IVF) on ischaemic placental disease in autologous oocyte IVF more than donor oocyte IVF

BACKGROUND

Ischaemic placental disease (IPD) affects 16%-23% of pregnancies in the United States. In vitro fertilisation (IVF) is a risk factor for IPD, and the magnitude of increase in risk differs for individuals using donor oocytes (donor IVF) versus their own oocytes (autologous IVF). In addition, multifoetal gestations, which are more common in IVF than non-IVF pregnancies, also are a risk factor for IPD.

OBJECTIVE

To quantify the contribution of multifoetal gestations to the association between IVF and IPD.

METHODS

We conducted a retrospective cohort study at a tertiary hospital from 1 January, 2000 to 1 August 2018 using electronic medical records and state vital statistics data. IPD was defined as preeclampsia, placental abruption, small for gestational age (SGA) birth or an intrauterine foetal demise due to placental insufficiency. We used mediation analysis to decompose the total effect of IVF on IPD into a natural direct effect and an indirect effect through multifoetal gestations. We repeated the analyses separately for donor and autologous IVF. All models were adjusted for maternal age, race, parity, insurance, year of delivery and account for multiple pregnancies per person.

RESULTS

We identified 86,514 deliveries, of which 281 resulted from donor IVF and 4173 resulted from autologous IVF. IVF pregnancies had 1.99 (95% CI 1.88, 2.10) times the risk of IPD compared to non-IVF pregnancies, and 75.5% of this increased risk was mediated by multifoetal gestations. Autologous IVF pregnancies had 1.95 (95% CI 1.84, 2.07) times the risk of IPD compared to non-IVF pregnancies, and the per cent mediated was 78.8%. Donor IVF pregnancies had 2.50 (95% CI 2.09, 2.92) times the risk of IPD, but the per cent mediated was 37.5%.

CONCLUSION

The majority of the association between autologous IVF and IPD was mediated through multifoetal gestations; however, this was not the case for donor IVF pregnancies.

Risk-Factor Based Lead Screening and Correlation with Blood Lead Levels in Pregnancy

OBJECTIVES

Lead exposure has devastating neurologic consequences for children and may begin in utero. The American College of Obstetricians and Gynecologists recommends prenatal lead screening using a risk factor-based approach rather than universal blood testing. The clinical utility of this approach has not been studied. We evaluated a risk-factor based questionnaire to detect elevated blood lead levels in pregnancy.

METHODS

We performed a secondary analysis of a cohort of parturients enrolled to evaluate the association of lead with hypertensive disorders of pregnancy. We included participants in this analysis if they had a singleton pregnancy ≥ 34 weeks' gestation with blood lead levels recorded. Participants completed a lead risk factor survey modified for pregnancy. We defined elevated blood lead as ≥ 2 μg/dL, as this was the clinically reportable level.

RESULTS

Of 102 participants enrolled in the cohort, 92 had blood lead measured as part of the study. The vast majority (78%) had 1 or more risk factor for elevated lead using the questionnaire yet none had clinical blood lead testing during routine visits. Only two participants (2.2%) had elevated blood lead levels. The questionnaire had high sensitivity but poor specificity for predicting detectable lead levels (sensitivity 100%, specificity 22%).

CONCLUSIONS FOR PRACTICE

Prenatal risk-factor based lead screening appears underutilized in practice and does not adequately discriminate between those with and without elevated blood levels. Given the complexity of the risk factor-based approach and underutilization, the benefit and cost-effectiveness of universal lead testing should be further explored.

Placental Abnormalities and Placenta-Related Complications Following In-Vitro Fertilization: Based on National Hospitalized Data in China

INTRODUCTION

Emerging evidence has shown that in-vitro fertilization (IVF) is associated with higher risks of certain placental abnormalities or complications, such as placental abruption, preeclampsia, and preterm birth. However, there is a lack of large population-based analysis focusing on placental abnormalities or complications following IVF treatment. This study aimed to estimate the absolute risk of placental abnormalities or complications during IVF-conceived pregnancy.

METHODS

We conducted a retrospective cohort study of 16 535 852 singleton pregnancies with delivery outcomes in China between 2013 and 2018, based on the Hospital Quality Monitoring System databases. Main outcomes included placental abnormalities (placenta previa, placental abruption, placenta accrete, and abnormal morphology of placenta) and placenta-related complications (gestational hypertension, preeclampsia, eclampsia, preterm birth, fetal distress, and fetal growth restriction (FGR)). Poisson regression modeling with restricted cubic splines of exact maternal age was used to estimate the absolute risk in both the IVF and non-IVF groups.

RESULTS

The IVF group (n = 183 059) was more likely than the non-IVF group (n = 16 352 793) to present placenta previa (aRR: 1.87 [1.83-1.91]), placental abruption (aRR: 1.16 [1.11-1.21]), placenta accrete (aRR: 2.00 [1.96-2.04]), abnormal morphology of placenta (aRR: 2.12 [2.07 to 2.16]), gestational hypertension (aRR: 1.55 [1.51-1.59]), preeclampsia (aRR: 1.54 [1.51-1.57]), preterm birth (aRR: 1.48 [1.46-1.51]), fetal distress (aRR: 1.39 [1.37-1.42]), and FGR (aRR: 1.36 [1.30-1.42]), but no significant difference in eclampsia (aRR: 0.91 [0.80-1.04]) was found. The absolute risk of each outcome with increasing maternal age in both the IVF and non-IVF group presented two patterns: an upward curve showing in placenta previa, placenta accreta, abnormal morphology of placenta, and gestational hypertension; and a J-shape curve showing in placental abruption, preeclampsia, eclampsia, preterm birth, fetal distress, and FGR.

CONCLUSION

IVF is an independent risk factor for placental abnormalities and placental-related complications, and the risk is associated with maternal age. Further research is needed to evaluate the long-term placenta-related chronic diseases of IVF patients and their offspring.

Pre-eclampsia in pregnancies resulting from oocyte donation, natural conception or IVF: a systematic review and meta-analysis

STUDY QUESTION

What is the prevalence of pre-eclampsia (PE) in pregnancies after oocyte donation (OD) compared to natural conception (NC) and to IVF with autologous oocytes (AO)?

SUMMARY ANSWER

Overall the prevalence of PE after OD was 4-5 times higher than after NC and 2-3 times higher than after IVF with AO.

WHAT IS KNOWN ALREADY

The indication for OD is expanding to lesbian women requesting shared lesbian motherhood. Previous reviews have shown that the risk of PE is higher in pregnancies after OD than after NC and after IVF with AO. Classification on the severity of PE is lacking as is the relationship with known risk factors such as maternal age and multiple gestations. Furthermore the actual prevalence of PE in pregnancies resulting from OD is not known.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was conducted. A literature search was performed using the following databases: PubMed, EMBASE and CINAHL, OpenGrey and Greynet from January 1980 through July 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included retrospective and prospective cohort studies. The study population consisted of pregnancies after OD and NC or IVF and data had to be available about prevalence of PE. We compared the risk of (severe) PE in OD versus NC and IVF pregnancies, subgrouped by plurality and maternal age. We calculated individual and pooled odds ratios (OR) and prevalence estimates with 95% CI using a random effect model, while heterogeneity was assessed by the I2.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 27 studies comprising of 7089 OD pregnancies, 1 139 540 NC pregnancies and 72 742 IVF pregnancies were available for analysis. The risks of PE and severe PE was increased in OD pregnancies compared to NC pregnancies (pooled OR of all subgroups: 5.09, 95% CI: 4.29-6.04; I2 = 19% and OR: 7.42, 95% CI: 4.64-11.88; I2 = 49%, respectively). This suggests that compared to a PE risk of 2.9% with NC, the risk with OD was between 11.5% and 15.4%. Compared to a severe PE risk of 0.5% with NC, the risk with OD was between 2.3% and 5.6%. The pooled adjusted OR for PE was 3.24 (95% 2.74-3.83) for OD versus NC pregnancies. The risks of PE and severe PE were also increased in OD pregnancies compared to IVF pregnancies (pooled OR of all subgroups: 2.97, 95% CI: 2.49-3.53; I2 = 51% and OR: 2.97, 95% CI: 2.15-4.11; I2 = 0%, respectively). This suggests that compared to a PE risk of 5.9% with IVF, the risk with OD was between 13.5% and 18.0%. Compared to a severe PE risk of 3.3% with IVF, the risk with OD was between 6.8% and 12.2%. The pooled adjusted OR for PE was 2.67 (95% 2.28-3.13) for OD versus IVF. The pooled prevalence of PE in singleton pregnancies after OD was 10.7% (95% CI 6.6-15.5) compared to 2.0% (95% CI 1.0-3.1) after NC and 4.1% (95% CI 2.7-5.6) after IVF. The prevalence in multiple pregnancies was 27.8% (95% CI 23.6-32.2) after OD, 7.5% (95% CI 7.2-7.8) after NC and 9.7% (95% CI 6.2-13.9) after IVF.

LIMITATIONS, REASONS FOR CAUTION

The precise definition of PE is still a matter of debate. The different criteria could have affected the prevalence estimate.

WIDER IMPLICATIONS OF THE FINDINGS

Nearly one in six women will suffer PE after OD. Although it is uncertain whether these risks are consistent for lesbian couples undergoing shared motherhood, we feel that women who can conceive naturally could be advised to reconsider. In women with primary ovarian insufficiency, we feel that factors that may increase risk of PE ever further, such as double embryo transfer, should be avoided whenever possible.

STUDY FUNDING/COMPETING INTEREST(S)

No funding or competing interests.

REGISTRATION NUMBER

CRD42020166899.

Placenta Accreta Spectrum: In Vitro Fertilization and Non-In Vitro Fertilization and Placenta Accreta Spectrum in a Massachusetts Cohort

OBJECTIVE

The incidence of placenta accreta spectrum (PAS) has been increasing in the United States. In addition, there has also been an increase in the utilization of in vitro fertilization (IVF). The IVF pregnancies confer an increased risk of adverse obstetric and neonatal outcomes, but there is limited data on whether IVF is associated with PAS. The aim of this study is to assess the association between IVF and the risk of PAS.

STUDY DESIGN

This was a retrospective cohort study of deliveries from January 1, 2013 to August 1, 2018 at a tertiary hospital in the Massachusetts. IVF pregnancies were compared with non-IVF pregnancies, and PAS diagnosis was confirmed by histopathology reports. Hospital administrative data and medical record review were used, and supplemented with data from birth certificates from the Massachusetts Department of Public Health.

RESULTS

We identified 28,344 pregnancies that met inclusion criteria, of which 1,418 (5.0%) were IVF pregnancies. The overall incidence of PAS was 0.4% (2.2% in the IVF group and 0.3% in the non-IVF group). Women who underwent IVF had 5.5 times the risk of PAS (95% confidence interval [CI]: 3.4-8.7) compared with women in the non-IVF group, adjusted for maternal age, nulliparity, and year of delivery (Table 5). Compared with women in the non-IVF group, the IVF group had fewer prior cesarean deliveries (22.6 vs. 64.2%) and a lower prevalence of placenta previa (19.4 vs. 44.4%).

CONCLUSION

Women with an IVF pregnancy carry an increased risk of PAS compared with non-IVF. Among women who underwent IVF, there was a lower prevalence of prior cesarean deliveries and placenta previa. Future work is needed to identify the mechanism of association for this increased risk as well as a reliable tool for antenatal detection in this cohort of women.

KEY POINTS

· IVF pregnancies have higher risk of PAS than non-IVF pregnancies.. · IVF pregnancies with PAS do not exhibit common risk factors.. · IVF may be an independent risk factor for PAS..

Angiogenic factors and prediction for ischemic placental disease in future pregnancies

OBJECTIVES

Ischemic placental disease (IPD), including preeclampsia, abruption, and fetal growth restriction, often recurs in subsequent pregnancies. Angiogenic factors of placental origin have been implicated in the pathogenesis of preeclampsia, but have not been studied as predictors of IPD in subsequent pregnancies. We hypothesized that elevated angiogenic factors in an index pregnancy would be associated with recurrence of IPD.

STUDY DESIGN

We conducted a retrospective cohort study of patients undergoing evaluation for preeclampsia who had angiogenic factors measured in an index pregnancy and experienced a subsequent pregnancy at the same institution. Patients with IPD in the index pregnancy were included. A high ratio of soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) was defined as greater than or equal to 85.

MAIN OUTCOME MEASURES

The primary outcome was IPD in a subsequent pregnancy.

RESULTS

We included 109 patients in the analysis. The sFlt1/PlGF ratio was elevated in 30% of participants. Those with an elevated ratio were more likely to be nulliparous in the index pregnancy, and less likely to have chronic hypertension. The recurrence of IPD in the study was 27%, with a non-significant difference in risk based on a high sFlt-1/P1GF ratio RR 0.58 (95% CI 0.21 - 1.6) compared to a low ratio.

CONCLUSIONS

A high sFlt1/P1GF ratio in an index pregnancy is not associated with a higher risk of IPD in a subsequent pregnancy. These data suggest placental angiogenic biomarkers are specific to the pregnancy and not a reflection of maternal predisposition to IPD.

Language Preference and Risk of Primary Cesarean Delivery: A Retrospective Cohort Study

OBJECTIVES

While some medical indications for cesarean delivery are clear, subjective provider and patient factors contribute to the rising cesarean delivery rates and marked disparities between racial/ethnic groups. We aimed to determine the association between language preference and risk of primary cesarean delivery.

METHODS

We conducted a retrospective cohort study of nulliparous, term, singleton, vertex (NTSV) deliveries of patients over 18 years old from 2011-2016 at an academic medical center, supplemented with data from the Massachusetts Department of Public Health. We used modified Poisson regression with robust error variance to calculate risk ratios for cesarean delivery between patients with English language preference and other language preference, with secondary outcomes of Apgar score, maternal readmission, blood transfusion, and NICU admission.

RESULTS

Of the 11,298 patients included, 10.3% reported a preferred language other than English, including Mandarin and Cantonese (61.7%), Portuguese (9.7%), and Spanish (7.5%). The adjusted risk ratio for cesarean delivery among patients with a language preference other than English was 0.85 (95% CI 0.72-0.997; p = 0.046) compared to patients with English language preference. No significant differences in risk of secondary outcomes between English and other language preference were found.

DISCUSSION

After adjusting for confounders, this analysis demonstrates a decreased risk of cesarean delivery among women who do not have an English language preference at one institution. This disparity in cesarean delivery rates in an NTSV population warrants future research, raising the question of what clinical and social factors may be contributing to these lower cesarean delivery rates.

A systematic review of quantitative bias analysis applied to epidemiological research

BACKGROUND

Quantitative bias analysis (QBA) measures study errors in terms of direction, magnitude and uncertainty. This systematic review aimed to describe how QBA has been applied in epidemiological research in 2006-19.

METHODS

We searched PubMed for English peer-reviewed studies applying QBA to real-data applications. We also included studies citing selected sources or which were identified in a previous QBA review in pharmacoepidemiology. For each study, we extracted the rationale, methodology, bias-adjusted results and interpretation and assessed factors associated with reproducibility.

RESULTS

Of the 238 studies, the majority were embedded within papers whose main inferences were drawn from conventional approaches as secondary (sensitivity) analyses to quantity-specific biases (52%) or to assess the extent of bias required to shift the point estimate to the null (25%); 10% were standalone papers. The most common approach was probabilistic (57%). Misclassification was modelled in 57%, uncontrolled confounder(s) in 40% and selection bias in 17%. Most did not consider multiple biases or correlations between errors. When specified, bias parameters came from the literature (48%) more often than internal validation studies (29%). The majority (60%) of analyses resulted in >10% change from the conventional point estimate; however, most investigators (63%) did not alter their original interpretation. Degree of reproducibility related to inclusion of code, formulas, sensitivity analyses and supplementary materials, as well as the QBA rationale.

CONCLUSIONS

QBA applications were rare though increased over time. Future investigators should reference good practices and include details to promote transparency and to serve as a reference for other researchers.

Risk of stillbirth in singleton gestations following in vitro methods of conception: a systematic review and meta-analysis

BACKGROUND

In vitro methods of conception are associated with adverse perinatal outcomes. It is unclear if the risk of stillbirth is increased also.

OBJECTIVE

This systematic review and meta-analysis aimed to estimate the risk of stillbirth in singleton gestations following in vitro methods of conception compared to non-in vitro conceptions.

SEARCH STRATEGY

A comprehensive search in PubMed, Embase, CINAHL, and Cochrane Library was undertaken from database inception to February 2021, with backward citation tracking.

SELECTION CRITERIA

Eligible studies included randomized controlled trials, cohort studies, or case-control studies that assessed stillbirth following in vitro fertilisation and/or intracytoplasmic sperm injection in comparison to non-in vitro methods of conception, including spontaneous conceptions, intrauterine insemination, and ovarian stimulation.

DATA COLLECTION AND ANALYSIS

The Newcastle-Ottawa Scale was used to assess risk of bias. A summary odds ratio (OR) for stillbirth following in vitro methods of conception compared to non-in vitro methods was calculated using a random-effects model for meta-analysis.

MAIN RESULTS

Thirty-three cohort studies met inclusion criteria. There was an increased risk of stillbirth with in vitro methods: OR 1.41 (95% CI 1.20-1.65); however, the crude baseline risk of stillbirth was low (4.44/1000 total births). Subgroup analysis did not demonstrate an increased risk when in vitro methods were compared to conception without in vitro methods in the context of subfertility.

CONCLUSIONS

Compared to non-in vitro conceptions, in vitro conceptions have an increased risk of stillbirth. However, there is insufficient evidence to demonstrate whether this risk is associated with in vitro techniques or underlying subfertility.

TWEETABLE ABSTRACT

This meta-analysis found an increased risk of stillbirth in singletons from in vitro methods of conception.

Elevated serum progesterone during in vitro fertilization treatment and the risk of ischemic placental disease

BACKGROUND

Elevated progesterone on the day of human chorionic gonadotropin (hCG) administration is associated with decreased live birth rates in IVF cycles. The association with adverse pregnancy outcomes is unknown.

OBJECTIVES

Assess the association between serum progesterone on the day of hCG administration and the risk of ischemic placental disease [IPD; preeclampsia, placental abruption, and/or small for gestational age (SGA)].

METHODS

We conducted a retrospective cohort study of autologous fresh IVF cycles resulting in delivery between 2005 and 2018. All IVF procedures were conducted at a large, university-affiliated infertility center. Patients were divided into tertiles based on their serum progesterone level on the day of hCG administration; the lowest tertile served as the reference group. We identified pregnancies complicated by preeclampsia and placental abruption using ICD-9/10 codes and medical record review. We defined SGA as < 10th percentile using U.S. growth curves.

RESULTS

The cohort included 166 deliveries in the lowest tertile of progesterone (0.2-0.73 ng/ml), 166 deliveries in the middle (0.64-1.05 ng/ml) and 167 deliveries in the highest tertile (1.05-5.6 ng/ml). Compared with the lowest tertile, the risk of IPD was greater in the middle (RR 1.6; 95% CI 1.1-2.5) tertile after adjustment for age, parity, number of oocytes retrieved, and estradiol. The highest tertile was also not associated with an increased risk of IPD.

CONCLUSION

In an IVF population, elevated serum progesterone in the range of 0.64-1.05 ng/mL on the day of hCG administration was associated with a small increased risk of IPD.

Association between in vitro fertilization and ischemic placental disease by gestational age

OBJECTIVE

To evaluate the association between in vitro fertilization (IVF) and ischemic placental disease (IPD), stratified by gestational age.

DESIGN

We performed a secondary analysis of a retrospective cohort study of deliveries.

SETTING

Deliveries were performed over 15 years at a single tertiary hospital.

PATIENT(S)

We included all parturients who had a live born infant or an intrauterine fetal demise (IUFD).

INTERVENTION(S)

We compared pregnancies resulting from IVF cycles to non-IVF pregnancies.

MAIN OUTCOME MEASURE(S)

The primary outcomes were preterm and term IPD (preeclampsia, placental abruption, small-for-gestational age infant [SGA], or an intrauterine fetal demise [IUFD] due to placental insufficiency).

RESULT(S)

Of the 69,084 deliveries during the study period, 3,763 (5.4%) were conceived with IVF. The incidence of preterm delivery was 32.6% in IVF pregnancies and 10.8% in non-IVF pregnancies. Multiple gestations were more common in IVF pregnancies. Compared to non-IVF pregnancies, IVF pregnancies were more likely to develop both preterm and term IPD, even after adjustment for maternal age and parity. The risk of preterm IPD was 4 times higher (95% confidence interval, 3.7-4.4) in patients who underwent IVF compared with those who did not undergo IVF. Among parturients who delivered at ≥37 weeks of gestation, IVF pregnancies had 1.7 times the risk of term IPD (95% confidence interval, 1.6-1.9) compared with non-IVF pregnancies.

CONCLUSION(S)

IVF was strongly associated with preterm IPD. We found a similar, but attenuated, association between IVF and term IPD. The stronger association with preterm IPD suggests an association between IVF and placental insufficiency.