Association between maternal comorbidity and preterm birth by severity and clinical subtype: retrospective cohort study

Maternal Occupational Risk Factors and Preterm Birth: A Systematic Review and Meta-Analysis

Objective: This systematic review and meta-analysis aimed to summarize the evidence on the relationship between physical occupational risks (high physical workload, long working hours, shift work, whole-body vibrations, prolonged standing, and heavy lifting) and preterm birth. Methods: A systematic review and meta-analysis was conducted across six databases to investigate the relationship between physical occupational risks and preterm birth. Result: A comprehensive analysis of 37 studies with varying sample sizes found moderate evidence of positive associations between high physical workload, long working hours, shift work, whole-body vibration, and preterm birth. Meta-analysis showed a 44% higher risk (OR 1.44, 95% CI 1.25-1.66) for preterm birth with long working hours and a 63% higher risk (OR 1.63, 95% CI 1.03-2.58) with shift work. Conclusion: Pregnant women in physically demanding jobs, those working long hours or on shifts, and those exposed to whole-body vibration have an increased risk of preterm birth. Employers should establish supportive workplaces, policymakers implement protective measures, healthcare providers conduct screenings, and pregnant women must stay informed and mitigate these job-related risks. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], Identifier [CRD42022357045].

Time-varying effects are common in genetic control of gestational duration

Preterm birth is a major burden to neonatal health worldwide, determined in part by genetics. Recently, studies discovered several genes associated with this trait or its continuous equivalent-gestational duration. However, their effect timing, and thus clinical importance, is still unclear. Here, we use genotyping data of 31 000 births from the Norwegian Mother, Father and Child cohort (MoBa) to investigate different models of the genetic pregnancy 'clock'. We conduct genome-wide association studies using gestational duration or preterm birth, replicating known maternal associations and finding one new fetal variant. We illustrate how the interpretation of these results is complicated by the loss of power when dichotomizing. Using flexible survival models, we resolve this complexity and find that many of the known loci have time-varying effects, often stronger early in pregnancy. The overall polygenic control of birth timing appears to be shared in the term and preterm, but not very preterm, periods and exploratory results suggest involvement of the major histocompatibility complex genes in the latter. These findings show that the known gestational duration loci are clinically relevant and should help design further experimental studies.

Determinants for perinatal adverse outcomes among pregnant women with preterm premature rupture of membrane: A prospective cohort study

Background

One of the most critical functions of the fetal membranes is to remain intact until the onset of labor to maintain the protective intrauterine fluid environment. In most pregnancies, spontaneous rupture usually occurs near the end of the first stage of labor. Preterm premature membrane rupture (PROM) occurs when the fetal membrane ruptures before 37 weeks of pregnancy, and it contributes to adverse maternal, fetal, and neonatal outcomes. Therefore, this study aimed to determine the association of determinant factors with adverse perinatal outcomes.

Methods

A prospective cohort study was conducted on pregnant women with preterm premature membrane rupture (n = 160) attending the teaching hospitals at Addis Ababa University. Socio-demographic and obstetric risk factors with adverse perinatal outcomes include the 5th minute Apgar score, neonatal intensive care unit (NICU) admission, early-onset neonatal sepsis (EONS), respiratory distress syndrome (RDS), perinatal mortality, Chorioamnionitis, and placental abruption were assessed. SPSS version 24, t-test, χ ² test, and logistic regression analysis were used. P-values <0.25 in the bivariate and p < 0.05 in the multiple logistic regression were considered statistically significant.

Results

The preterm (PROM) rate was 2.2% with perinatal mortality rate of 206/1,000. Gestational age (GA) at delivery was the determinate for low Apgar score at the 5th minute (AOR: 7.23; 95% CI, 1.10, 47.6; p = 0.04). Unable to use steroid (AOR: 8.23; 95% CI, 1.83, 37.0; p = 0.000), GA at membrane rupture (AOR: 4.61; 95% CI, 1.98, 31.8; p = 0.000) and delivery (AOR: 4.32; 95% CI, 1.99, 30.9; p = 0.000) were determinates for NICU admission. EONS was significantly affected by GA at membrane rupture (AOR: 5.9; 95% CI, 1.01, 37.0; p = 0.04). Placental abruption was significantly affected by GA at delivery (AOR: 7.52; 95% CI, 1.15, 48.96; p = 0.04).

Conclusion

GA at membrane rupture and delivery was the most critical predictors of adverse perinatal outcomes. Local guidelines on the approach and preterm PROM outcome management need to be prepared.

Revealing the impact of lifestyle stressors on the risk of adverse pregnancy outcomes with multitask machine learning

Psychosocial and stress-related factors (PSFs), defined as internal or external stimuli that induce biological changes, are potentially modifiable factors and accessible targets for interventions that are associated with adverse pregnancy outcomes (APOs). Although individual APOs have been shown to be connected to PSFs, they are biologically interconnected, relatively infrequent, and therefore challenging to model. In this context, multi-task machine learning (MML) is an ideal tool for exploring the interconnectedness of APOs on the one hand and building on joint combinatorial outcomes to increase predictive power on the other hand. Additionally, by integrating single cell immunological profiling of underlying biological processes, the effects of stress-based therapeutics may be measurable, facilitating the development of precision medicine approaches.

Objectives

The primary objectives were to jointly model multiple APOs and their connection to stress early in pregnancy, and to explore the underlying biology to guide development of accessible and measurable interventions.

Materials and Methods

In a prospective cohort study, PSFs were assessed during the first trimester with an extensive self-filled questionnaire for 200 women. We used MML to simultaneously model, and predict APOs (severe preeclampsia, superimposed preeclampsia, gestational diabetes and early gestational age) as well as several risk factors (BMI, diabetes, hypertension) for these patients based on PSFs. Strongly interrelated stressors were categorized to identify potential therapeutic targets. Furthermore, for a subset of 14 women, we modeled the connection of PSFs to the maternal immune system to APOs by building corresponding ML models based on an extensive single cell immune dataset generated by mass cytometry time of flight (CyTOF).

Results

Jointly modeling APOs in a MML setting significantly increased modeling capabilities and yielded a highly predictive integrated model of APOs underscoring their interconnectedness. Most APOs were associated with mental health, life stress, and perceived health risks. Biologically, stressors were associated with specific immune characteristics revolving around CD4/CD8 T cells. Immune characteristics predicted based on stress were in turn found to be associated with APOs.

Conclusions

Elucidating connections among stress, multiple APOs simultaneously, and immune characteristics has the potential to facilitate the implementation of ML-based, individualized, integrative models of pregnancy in clinical decision making. The modifiable nature of stressors may enable the development of accessible interventions, with success tracked through immune characteristics.

The Predictive Role of Maternal Biological Markers and Inflammatory Scores NLR, PLR, MLR, SII, and SIRI for the Risk of Preterm Delivery

In many countries, preterm birth, defined as birth before 37 completed weeks of gestation, is the primary cause of infant death and morbidity. An increasing body of research suggests that inflammation (both clinical and subclinical) plays a significant role in inducing preterm labor or developing pregnancy problems that lead to premature birth. Consequently, the purpose of this research was to determine the predictive value of the Neutrophil-Lymphocyte Ratio (NLR), derived Neutrophil-Lymphocyte Ratio (dNLR), Monocytes-to-Lymphocyte Ratio (MLR), Platelets-to-Lymphocyte Ratio (PLR), Systemic immune-inflammation index (SII), and systemic inflammatory response index (SIRI), for premature delivery. A retrospective study analyzed a total of 243 eligible pregnancies that resulted in a preterm birth during 2020 and 2021. A control group without a history of preterm birth was matched by age and trimester of laboratory analysis at a 1:1 ratio. Although the number of comorbidities was similar among study groups, the body-mass index estimated for the week of gestation was significantly higher among the patients from the prematurity group, as well as the prevalence of urinary tract infections and smoking. Laboratory data showed that patients with a preterm birth had significantly higher white blood cell count and monocytes, but significantly lower lymphocytes, platelets, and hemoglobin. The NLR, dNLR, PLR, and MLR scores showed to be significantly higher among patients from the prematurity group, but SII and SIRI were not significantly different between the study groups. It was observed that the AUC values of NLR, dNLR, PLR, and MLR were higher than 0.600, respectively NLR had the highest value among the tested scores (AUC = 0.694) and the highest sensitivity in this study (71%). The highest sensibility was achieved by dNLR, with 70%, and an AUC value of 0.655 (p-value = 0.022). PLR had the second-highest AUC value (0.682) and the best score in terms of sensitivity (70%) and sensibility (69%) (p-value = 0.015). Lastly, MLR had the lowest significant AUC score (0.607) and lowest sensitivity/sensibility. The significant cut-off values for the inflammatory scores were 9.0 for NLR, 9.8 for dNLR, 250 for PLR, and 4.07 for MLR. After evaluating the importance of these inflammatory scores, further clinical applications should be conducted to confirm the results and improve therapy and care to reduce the burden of premature deliveries.

Maternal Risk Factors Associated with Preterm Births among Pregnant Women in Mogadishu, Somalia

Background: Premature birth impacts millions of newborns annually. Sixty percent of the world’s preterm births occur in Sub-Saharan Africa and South Asia. Somalia’s premature birth rates and maternal risk factors are poorly studied; hence, this study aims to identify maternal risk factors related to premature births in Mogadishu, Somalia. Methods: This unmatched case-control study was conducted at four maternity hospitals in Mogadishu, Somalia. The cases were newborns with gestational ages of less than 37 weeks; controls were newborns with gestational ages of 37 to 42 weeks. All were live singletons. Cross-tabulation and binary logistic regression were used to analyze the data; a p-value of 0.05 was deemed statistically significant. Result: Of the total of 499 newborns, 70 were cases, and 429 were controls. Adequate prenatal care, maternal urine analysis, tetanus toxoid (TT) vaccination, hemoglobin (Hb) measurement, ultrasound monitoring, intake of iron + folic acid (IFA) supplement, blood pressure (BP) measurement during the current pregnancy, as well as partograph usage during labor all significantly decreased risk of having premature births. A prior history of preterm delivery and preeclampsia, obstetric complications, and female genital mutilation (FGM) significantly increased the risk of preterm births. Conclusion: The utilization of antenatal care services, use of a partograph, obstetric complications, and prior history of premature birth and preeclampsia had a substantial effect on preterm birth rates. This study identifies female genital mutilation (FGM) as a previously unidentified risk factor for preterm birth that needs additional investigation.

Dense phenotyping from electronic health records enables machine learning-based prediction of preterm birth

BACKGROUND

Identifying pregnancies at risk for preterm birth, one of the leading causes of worldwide infant mortality, has the potential to improve prenatal care. However, we lack broadly applicable methods to accurately predict preterm birth risk. The dense longitudinal information present in electronic health records (EHRs) is enabling scalable and cost-efficient risk modeling of many diseases, but EHR resources have been largely untapped in the study of pregnancy.

METHODS

Here, we apply machine learning to diverse data from EHRs with 35,282 deliveries to predict singleton preterm birth.

RESULTS

We find that machine learning models based on billing codes alone can predict preterm birth risk at various gestational ages (e.g., ROC-AUC = 0.75, PR-AUC = 0.40 at 28 weeks of gestation) and outperform comparable models trained using known risk factors (e.g., ROC-AUC = 0.65, PR-AUC = 0.25 at 28 weeks). Examining the patterns learned by the model reveals it stratifies deliveries into interpretable groups, including high-risk preterm birth subtypes enriched for distinct comorbidities. Our machine learning approach also predicts preterm birth subtypes (spontaneous vs. indicated), mode of delivery, and recurrent preterm birth. Finally, we demonstrate the portability of our approach by showing that the prediction models maintain their accuracy on a large, independent cohort (5978 deliveries) from a different healthcare system.

CONCLUSIONS

By leveraging rich phenotypic and genetic features derived from EHRs, we suggest that machine learning algorithms have great potential to improve medical care during pregnancy. However, further work is needed before these models can be applied in clinical settings.

Preeclampsia and Cardiovascular Risk for Offspring

There is growing evidence of long-term cardiovascular sequelae in children after in utero exposure to preeclampsia. Maternal hypertension and/or placental ischaemia during pregnancy increase the risk of hypertension, stroke, diabetes, and cardiovascular disease (CVD) in the offspring later in life. The mechanisms associated with CVD seem to be a combination of genetic, molecular, and environmental factors which can be defined as fetal and postnatal programming. The aim of this paper is to discuss the relationship between pregnancy complicated by preeclampsia and possibility of CVD in the offspring. Unfortunately, due to its multifactorial nature, a clear dependency mechanism between preeclampsia and CVD is difficult to establish.

Perinatal Maternal-Fetal/Neonatal Transmission of COVID-19: A Guide to Safe Maternal and Neonatal Care in the Era of COVID-19 and Physical Distancing

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), is highly contagious and can cause serious respiratory illness and other clinical manifestations. The aim of this review is to summarize the clinical presentation, diagnosis, and outcomes of COVID-19 in pregnant women and neonates, who may be especially vulnerable to the effects of COVID-19, and to discuss what is known about potential maternal-fetal and maternal-neonatal transmission of SARS-CoV-2.

Epidemiology of Birth Defects in Very Low Birth Weight Infants in Japan

OBJECTIVE

To evaluate the mortality and morbidity of very low birth weight (VLBW) preterm infants with birth defects in Japan.

STUDY DESIGN

Data were collected prospectively for infants weighing <1501 g and born at <37 weeks of gestation admitted to centers of the Neonatal Research Network of Japan during 2003-2016. We compared outcomes of infants with and without birth defects using Pearson χ² test, Wilcoxon rank-sum test, log-rank test, nominal logistic regression analysis, and stratified analysis by birth defect subgroups. This study was approved by the Ethics Committee of Kyoto University Graduate School and Faculty of Medicine.

RESULTS

Among 57 730 VLBW preterm infants, 3557 infants (6.2%) were born with birth defects. Chromosomal abnormalities, congenital heart defects, and congenital malformation of the digestive system were the most common categories. Among diseases, Trisomy 18, Down syndrome, and cleft palate were the most prevalent. There were significant differences between perinatal characteristics of infants with and without birth defects. Most categories of morbidity occurred more frequently in infants with birth defects compared with those without birth defects. The aOR for mortality during the neonatal intensive care unit admission was 10.6 (95% CI 9.5-11.7) for infants with birth defects. A stratified analysis identified birth defect categories with good, moderate, and poor prognoses.

CONCLUSIONS

This detailed information about mortality and morbidity of preterm VLBW infants with birth defects should be useful for genetic counseling as well as prenatal and neonatal care, with the limitation that we lacked information about the timing of diagnosis, abortion, or stillbirth.

Ten-year time trends in preterm birth during a sociodemographic transition period: a retrospective cohort study in Shenzhen, China

OBJECTIVES

To investigate time trends of preterm birth and estimate the contributions of risk factors to the changes in preterm birth rates over a decade (2009-2018) of transitional period in Shenzhen, China.

DESIGN

Retrospective cohort study between 2009 and 2018.

SETTING

All births in Baoan during January 2009 and December 2018 registered in the Shenzhen Birth Registry Database.

PARTICIPANTS

478 044 live births were included with sociodemographic and medical records for both women and infants.

OUTCOME MEASURES

The incidence rate of preterm birth stratified by different maternal and infant characteristics. Multiple logistic regression was used to identify significant risk factors associated with preterm birth. The population attributable risk fraction of each factor was calculated to estimate its contribution to variations of preterm birth rate over the 10 years.

RESULTS

A total of 27 829 preterm births from 478 044 (5.8%) live births were recorded and the preterm birth rate increased from 5.5% in 2009 to 6.2% in 2018. Medically induced preterm birth rate increased from 2.0% in 2009 to 3.4% in 2018 while spontaneous preterm labour rate decreased from 3.3% to 2.7% over the decade years. Risk factors including multiple pregnancy (0.28% increase) drove the rise of preterm birth rate, whereas changes in maternal educational attainment (0.22% reduction) and prenatal care utilisation (0.45% reduction) had contributed to the decline in preterm birth rate.

CONCLUSIONS

An uptrend of preterm birth rate was observed in an area under rapid sociodemographic transitions during 2009-2018 and the changes were associated with these sociodemographic transitions. Continued investments in girls' education and prenatal care have the potential of reducing preterm birth rate.

Preterm parturition and pre-eclampsia: The confluence of two great gestational syndromes

BACKGROUND

Preterm birth (PTB) and pre-eclampsia independently, and frequently concurrently, adversely affect the pregnancy outcomes of millions of mothers and infants worldwide each year.

OBJECTIVES

To fill the gap between PTB and pre-eclampsia, which continue to constitute the two most important current global challenges to maternal and perinatal health.

METHODS

Pubmed, Embase, and Cochrane databases were searched from inception until December 2019 using the terms spontaneous PTB (SPTB), indicated preterm delivery (IPTD), early-onset pre-eclampsia, and pre-eclampsia.

RESULTS

History of PTB and pre-eclampsia were the strongest risk factors contributing to the occurrence of SPTB or IPTB. The risk of PTB and pre-eclampsia among non-Hispanic African American women was higher than the rate among all other racial/ethnic groups in the United States. Low-dose aspirin (LDA) has been reported to reduce the risk of pre-eclampsia by at least 10% and PTB by at least 14%. Lastly, women and their fetuses who develop early-onset pre-eclampsia are at higher risk for developing hypertension and cardiovascular disease later in life.

CONCLUSIONS

While better clarity is needed, efforts to coordinate prevention of both PTB and pre-eclampsia, even though imperfect, are critically important as part of any program to make motherhood as safe as possible.

Regulation of Keap-1/Nrf2 Signaling Pathway Is Activated by Oxidative Stress in Patients with Premature Rupture of Membranes

Background

The potential mechanisms underlying premature rupture of membrane (PROM) is still unknown. The aim of this study was to determine the role of Keap-1/Nrf2 signaling pathway activation by oxidative stress in patients with preterm premature rupture of membranes.

Material/Methods

Placental tissues from preterm premature rupture of membranes (PPROM) (n=20), full-term premature rupture of membranes (FPROM) (n=20), and normal-term births (n=20) were collected and amniotic tissues were separated from the placental tissues from pregnant women at Shandong Provincial Qianfoshan Hospital. RT-PCR and Western blot were used to detect the levels of factors in the Keap-1/Nrf2 signaling pathway. To investigate the roles of Nrf2, we downregulated Nrf2 expression using siRNA in primary human amniotic epithelial (HAE) cells.

Results

Among the control group, FPROM group, and PPROM group, the reactive oxygen species (ROS) levels were significantly increased in the FPROM and PPROM groups. The differences indicated higher levels of oxidative stress in amniotic tissues with FPROM and PPROM after downregulation of si-Nrf2 in HAE cells. Antioxidants were lower in amniotic tissues with the FPROM group and PPROM group than in the control group. The antioxidant enzymes catalase (CAT), glutathione (GSH), glutathione peroxidase (GSHPx), and superoxide dismutases (SOD1 and SOD2) were examined in amniotic tissues. We found that the ROS levels were significantly increased after downregulation of si-Nrf2 compared with the control group. We found that the expression of Heme Oxygenase-1 (HO-1) and Glycogen Synthase Kinase-3b (GSK-3b), which is critical in the Keap-1/Nrf2 signaling pathway, increased significantly after downregulation of si-Nrf2 in HAE cells.

Conclusions

We found that increased ROS levels and decreased antioxidant enzymes in the PPROM and FPROM patients compared with the control group.

First-Trimester Prediction of Preterm Prelabour Rupture of Membranes

BACKGROUND

Preterm prelabour rupture of membranes (PPRoM) is commonly associated with preterm delivery and affects up to 3% of all pregnancies. It is associated with high rates of morbidity and mortality for the mother and the newborn.

OBJECTIVES

To identify risk factors for PPRoM and develop a model for first-trimester prediction of risk of PPRoM.

METHODS

A retrospective analysis of a series of women who had first-trimester (11-13+6 weeks) screening for aneuploidy and pre-eclampsia and delivered in the same institution was performed. Univariate and multivariate logistic regression analyses were used to identify maternal and pregnancy factors and then develop a clinical prediction model for PPRoM.

RESULTS

10,280 women were screened between April 2010 and October 2016. 144 (1.4%) had PPRoM. Maternal factors predictive of PPRoM included nulliparity (parous women, OR 0.53; 95% CI 0.4-0.8), pre-existing diabetes mellitus (DM) (Type 1 DM, OR 6.7; 95% CI 2.3-19.4, Type 2 DM, OR 5.3; 95% CI 1.6-18.3), maternal age group (p = 0.004), and BMI category (p = 0.012). Uterine artery pulsatility index (UAPI) and biochemical parameters (PAPP-A, free βHCG) did not reach statistical significance. The predictive model had moderate efficacy with an area under the ROC curve of 0.67.

CONCLUSIONS

Several maternal characteristics collected during first-trimester screening predict PPRoM. Biomarkers currently measured during first-trimester screening (PAPP-A, βHCG, and UAPI) do not predict PPRoM. Whilst a predictive model can be generated with information currently collected at 11-13+6 weeks, this has only modest screening performance. First-trimester screening provides a structured framework where other predictors could improve model performance, and future studies should focus on the addition of other risk factors and biomarkers that may improve screening efficacy.

Profile of congenital heart disease in infants born following exposure to preeclampsia

BACKGROUND

Events in pregnancy play an important role in predisposing the newborn to the risk of developing CHD. This study evaluated the association between maternal preeclampsia and her offspring risk of CHD.

METHODS

This is a cohort study of 90 sex-matched neonates (45 each born to women with preeclampsia and normal pregnancy) in Jos, Nigeria. Anthropometry was taken shortly after delivery using standard protocols. Echocardiography was performed within 24 hours of life and repeated 7 and 28 days later. SPSS version 25 was used in all analyses. Statistical significance was set at p<0.05.

RESULTS

Congenital heart disease (CHD) was observed in 27 (30.0%) of newborns of women with preeclampsia compared with 11 (12.1%) of newborns without preeclampsia (p<0.001) at the end of 7 days and in 19 (21.1%) of newborns of women with preeclampsia and 3 (3.3%) of newborns of women without preeclampsia by the end of the 4th week of life (p<0.001). Overall, ASD (4 newborns), PDA (21 newborns), patent foramen ovale (14 newborns) and VSD (2 newborns) were the prevalent lesions found among all the newborns studied in the first week of life. Isolated atrial and ventricular septal defects were seen in 4 (4.4%) of the newborns of women with preeclampsia. Being the infant of a woman with preeclampsia was associated with about 8-fold increased risk of having CHD (OR = 7.9, 95% CI = 2.5-24.9, p<0.001).

CONCLUSION

CHD may be more common in newborns of women with preeclampsia underscoring the need for fetal and newborn screening for CHD in women with preeclampsia so as to improve their infant's well being.

Pregnancy outcomes among women with peptic ulcer disease

Background Little is known about the impact of peptic ulcer disease (PUD) on pregnancy. Our objective was to evaluate the effect of PUD on pregnancy and newborn outcomes. Methods A retrospective cohort study was carried out using the Healthcare Cost and Utilization Project (HCUP)-National Inpatient Sample (NIS) from the United States. The cohort consisted of all births that took place from 1999 to 2015. PUD was classified on the basis of the International Classification of Diseases-Ninth Revision (ICD-9) coding. Multivariate logistic regression was used to evaluate the adjusted effect of PUD on maternal and neonatal outcomes. Results Of the 13,792,544 births in this cohort, 1005 were to women with PUD (7/100,000 births). Between 1999 and 2015, prevalence of PUD in pregnancy increased from 4/100,000 to 11/100,000, respectively. Women with PUD were more commonly older and more likely to have comorbid illnesses. Women with PUD were at greater risk of preeclampsia [odds ratio (OR) 2.11, 95% confidence interval (CI) 1.67-2.66], preterm premature rupture of membranes (PPROM; OR 2.16, 95% CI 1.30-3.59), cesarean delivery (OR 1.60, 95% CI 1.40-1.82), venous thromboembolism (OR 3.77, 95% CI 2.08-6.85) and maternal death (OR 24.50, 95% CI 10.12-59.32). Births to women with PUD were at increased risk of intrauterine growth restriction (IUGR; OR 1.54, 95% CI 1.11-2.14), preterm birth (OR 1.84, 95% CI 1.54-2.21), intrauterine fetal death (OR 2.18, 95% CI 1.35-3.52) and congenital anomalies (OR 2.69, 95% CI 1.59-4.56). Conclusion The prevalence of PUD in pregnancy has risen over the last several years. PUD in pregnancy should be considered a high-risk condition associated with important adverse maternal and neonatal outcomes.

Maternal interpregnancy weight change and premature birth: Findings from an English population-based cohort study

Background

The relationship between maternal weight change between pregnancies and premature birth is unclear. This study aimed to investigate whether interpregnancy weight change between first and second, or second and third pregnancy is associated with premature birth.

Methods

Routinely collected data from 2003 to 2018 from one English maternity centre was used to produce two cohorts. The primary cohort (n = 14,961 women) consisted of first and second live-birth pregnancies. The secondary cohort (n = 5,108 women) consisted of second and third live-birth pregnancies. Logistic regression models were used to examine associations between interpregnancy BMI change and premature births adjusted for confounders. Subgroup analyses were carried out, stratifying by initial pregnancy BMI groups and analysing spontaneous and indicated premature births separately.

Results

In the primary cohort, 3.4% (n = 514) of births were premature compared to 4.2% (n = 212) in the secondary cohort, with fewer indicated than spontaneous premature births in both cohorts.

Primary cohort

Weight loss (>3kg/m²) was associated with increased odds of premature birth (adjusted odds ratio (aOR):3.50, 95% CI: 1.78–6.88), and spontaneous premature birth (aOR: 3.34, 95%CI: 1.60–6.98), in women who were normal weight (BMI 18.5-25kg/m²) at first pregnancy. Weight gain >1kg/m² was not associated with premature birth regardless of starting BMI.

Secondary cohort

Losing >3kg/m² was associated with increased odds of premature birth (aOR: 2.01, 95%CI: 1.05–3.87), when analysing the whole sample, but not when restricting the analysis to women who were overweight or obese at second pregnancy.

Conclusions

Normal-weight women who lose significant weight (>3kg/m²) between their first and second live pregnancies have greater odds of premature birth compared to normal-weight women who remain weight stable in the interpregnancy period. There was no evidence of association between weight change in women who were overweight or obese at the start of their first pregnancy and premature birth.

Risk Factors and Outcomes of Preterm Premature Rupture of Membranes in a Cohort of 6968 Pregnant Women Prospectively Recruited

We revisited risk factors and outcomes related to the preterm premature rupture of membranes (PPROM). A total of 7866 pregnant women were recruited during 5 years at their first prenatal visit to the perinatal clinic of the institution. We compared three groups (women without prematurity, women with spontaneous preterm labor with intact membranes (sPL with IM), women with PPROM) regarding 60 criteria about characteristics, lifestyle, medical, gynecological, obstetrical history of mothers, medication during pregnancy, events at delivery, and complications in neonates. Logistic regression analyses adjusting for potential confounding factors were used. Of the 6968 women selected, 189 (2.8%) presented a PPROM, and 225 (3.2%) an sPL with IM. The specific risk factors for PPROM were body mass index (BMI) <18.5 kg/m² (adjusted odds ratio, aOR: 2.00 (1.09-3.67)), history of PPROM (aOR: 2.75 (1.19-6.36)), nulliparity (aOR: 2.52 (1.77-3.60)), gestational diabetes (aOR: 1.87 (1.16-2.99)), and low level of education (aOR: 2.39 (1.20-4.78)). The complications associated with PPROM were abruption placentae, cesarean, APGAR 5' <4, birth weight <2500 g, stillbirth, neonatal jaundice, and hospitalization of mother and neonates. All these complications were also associated with sPL with IM. Our study confirms some of the risk factors of PPROM and highlights a new one: gestational diabetes. Outcomes of PPROM are related to prematurity.

Secular trends in pregnancy rates, delivery outcomes, and related health care utilization among women with congenital heart disease

BACKGROUND

The number of women with congenital heart disease (CHD) of reproductive age is increasing, yet a description of trends in pregnancy and delivery outcomes in this population is lacking.

OBJECTIVE

To assess secular trends in pregnancy rates, delivery outcomes, and related health care utilization in the adult female CHD population in Quebec, Canada.

METHODS

The Quebec CHD database was used to construct a cohort with all women with CHD aged 18-45 years between 1992 and 2004. Pregnancy and delivery rates were determined yearly and compared to the general population. Secular trends in pregnancy and delivery rates were assessed with linear regression. The cesarean delivery rate in the CHD population was compared to the general population. Predictors of cesarean section were determined with multivariable logistic regression. Cox regression, adjusted for comorbidities, was used to analyze the impact of cesarean sections on 1-year health care use following delivery.

RESULTS

About 14 878 women were included. A total of 10 809 pregnancies were identified in 5641 women, of whom 4551 (80%) and 2528 (45%) experienced at least one delivery and/or abortion, respectively. Absolute yearly numbers and rates of pregnancies and deliveries increased during the study period (P < .05). The increment in cesarean section rates was more pronounced among women with CHD than among the general population. Gestational diabetes (OR 1.50, 95% CI [1.13, 1.99]), gestational hypertension (OR 1.81, 95% CI [1.27, 2.57]), and preeclampsia (OR 1.59, 95% CI [1.11, 2.8]) were independent predictors of cesarean delivery. Cesarean sections were associated with postpartum cardiac-hospitalization within 1 year following delivery (HR = 2.35, 95% CI [1.05, 5.28]).

CONCLUSIONS

Yearly numbers and rates of pregnancies and deliveries in adult females with CHD rose significantly during the study period. Cesarean sections led to increased health care utilization. Further research is required to determine causes of high cesarean section rates in this patient population.

Does low dose aspirin prescribed for risk of early onset preeclampsia reduce the prevalence of preterm prelabor rupture of membranes?

Background: Placental dysfunction, inflammation and degradation of fetal membranes has been hypothesized as a cause of preterm prelabor of rupture of membranes.Objective: To examine the effect of aspirin, an anti-inflammatory agent, on the prevalence of preterm prelabor rupture of membranes (PPRoMs).Methods: A retrospective analysis was conducted to examine the effect of aspirin on the prevalence of PPRoM. Aspirin (150 mg, nocte) was prescribed to women who were identified through a screening program at 11-13⁺⁶ weeks' gestation as being at high risk for developing early-onset preeclampsia. Women who were at low risk for developing preeclampsia did not receive aspirin. The prevalence of PPRoM was compared with an observational cohort.Results: In the observational cohort, there were 3027 women, including 32 (1.1%) cases of PPRoM. The prevalence of PPRoM in the high risk group was 3.1% (4/128) and was statistically significantly higher compared to the low risk group (1.0%) (28/2899). The relative risk was 3.02 (95% CI 1.2-7.7; p= .04). In the interventional cohort, there were 7280 women, with 114 (1.6%) cases of PPRoM. The prevalence of PPRoM in the high risk group who were treated with aspirin was 1.8% (14/766) compared to 1.5% (100/6516) in the low risk group (p= .54). The prevalence of PPRoM in high risk patients in the observational group (who did not receive aspirin) compared with the high risk patients in the interventional group (who were treated with aspirin) was not statistically significant (p= .31).Conclusions: PPRoM is significantly associated with a description of high risk for ePET; although, this algorithm is not a good screening tool for predicting PPRoM. Aspirin treatment of women deemed high risk for ePET is safe in the context of PPRoM and there may be some reduction in prevalence of PPRoM in treated high risk women; although, this study was not powered to demonstrate a small reduction in the prevalence of PPRoM. The findings merit further investigation through a larger prospective study with adequate sample size.

Allostatic load, a measure of chronic physiological stress, is associated with pregnancy outcomes, but not fertility, among women with unexplained infertility

STUDY QUESTION

Among infertile women undergoing ovarian stimulation, is allostatic load (AL), a measure of chronic physiological stress, associated with subsequent fertility and pregnancy outcomes?

SUMMARY ANSWER

AL at baseline was not associated with conception, spontaneous abortion or live birth, however, it was significantly associated with increased odds of pre-eclampsia and preterm birth among women who had a live birth in the study.

WHAT IS KNOWN ALREADY

Several studies have linked AL during pregnancy to adverse outcomes including preterm birth and pre-eclampsia, hypothesizing that it may contribute to well-documented disparities in pregnancy and birth outcomes. However, AL biomarkers change over the course of pregnancy, raising questions as to whether gestational AL assessment is a valid measure of cumulative physiologic stress starting long before pregnancy. To better understand how AL may impact reproductive outcomes, AL measurement in the non-pregnant state (i.e. prior to conception) is needed.

STUDY DESIGN, SIZE, DURATION

A secondary data analysis based on data from 836 women who participated in Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS), a multi-center, randomized clinical trial of ovarian stimulation conducted from 2011 to 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovulatory women with unexplained infertility (ages 18-40) were enrolled and at baseline, biological and anthropometric measures were collected. AL scores were calculated as a composite of the following baseline variables determined a priori: BMI, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, dehydroepiandrosterone sulfate, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, C-reactive protein and HOMA score. Participants received ovarian stimulation for up to four cycles and if they conceived, were followed throughout pregnancy. We fit multi-variable logistic regression models examining AL (one-tailed and two-tailed) in relation to the following reproductive outcomes: conception, spontaneous abortion, live birth, pre-eclampsia, preterm birth and low birthweight.

MAIN RESULTS AND THE ROLE OF CHANCE

Adjusting for covariates, a unit increase in two-tailed AL score was associated with 62% increased odds of pre-eclampsia (OR: 1.62, 95% CI: 1.14, 2.38) 44% increased odds of preterm birth (OR: 1.44, 95% CI: 1.02, 2.08), and 39% increased odds of low birthweight (OR: 1.39, 95% CI: 0.99, 1.97). The relationship between AL and preterm birth was mediated by pre-eclampsia (P = 0.0003). In one-tailed AL analyses, associations were similar, but slightly attenuated. AL was not associated with fertility outcomes (conception, spontaneous abortion, live birth).

LIMITATIONS, REASONS FOR CAUTION

Results may not be generalizable to fertile women who conceive naturally or women with other types of infertility. Comparisons to previous, related work are difficult because variables included in AL composite measures vary across studies. AL may be indicative of overall poor health, rather than being specific to chronic physiological stress.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that chronic physiological stress may not impact success of ovarian stimulation, however, they confirm and extend previous work suggesting that AL is associated with adverse pregnancy outcomes. Physiological dysregulation due to chronic stress has been proposed as a possible mechanism underlying disparities in birth outcomes, which are currently poorly understood. Assessing biomarkers of physiological dysregulation pre-conception or in early pregnancy, may help to identify women at risk of adverse pregnancy outcomes, particularly pre-eclampsia.

STUDY FUNDING/COMPETING INTEREST(S)

Support for AMIGOS was provided by: U10 HD39005, U10 HD38992, U10 HD27049, U10 HD38998, U10 HD055942, HD055944, U10 HD055936 and U10HD055925. Support for the current analysis was provided by T32ES007271, R25HD075737, P30ES001247 and P30ES005022. This research was made possible by funding by American Recovery and Reinvestment Act. The content is solely the responsibility of the authors and does not necessarily represent the official views of NICHD, NIEHS or NIH. E.B., W.V., O.M., R.A., M.R., V.B., G.W.B., C.C., E.E., S.K., R.U., P.C, H.Z., N.S. and S.T. have nothing to disclose. R.L. reported serving as a consultant to Abbvie, Bayer, Kindex, Odega, Millendo and Fractyl and serving as a site investigator and receiving grants from Ferring. K.H. reported receiving grants from Roche Diagnostics and Ferring. R.R. reported a grant from AbbVie. M.D. reported being on the Board of Directors of and a stockholder in Advanced Reproductive Care.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov number: NCT01044862.

[Epidemiology, risk factors and child prognosis: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVES

To synthetize the available evidence regarding the incidence and risk factors of preterm premature rupture of membranes (PPROM). To describe the evolution of pregnancy, neonatal outcomes and the prognosis of infants born in a context of PPROM, according to the existence of an associated intrauterine infection and to the latency duration.

METHOD

Consultation of the Medline database, from 1980 to February 2018.

RESULTS

PPROM before 37 and before 34 weeks' gestation occur in 2-3% and <1% of pregnancies, respectively (LE2). Although many risk factors are identified, few are modifiable, and the vast majority of patients have no risk factors (LE2). Consequently, individual prediction of the risk of PPROM and primary prevention measures have not been shown to be effective and are not recommended in clinical practice (Grade B). Most women give birth within the week following PPROM (LE2). The main complications of PPROM are prematurity, intrauterine infection and obstetric and maternal complications (LE2). Latency duration and the frequency of complications decrease with increasing gestational age at PPROM (LE2). Neonatal prognosis is largely conditioned by gestational age at birth, with no apparent over-risk of poor outcomes linked to PPROM compared to other causes of preterm birth (LE2). In contrast, intrauterine infection is associated with an increased risk of in utero fetal death (LE3), necrotizing enterocolitis (LE1) and early-onset sepsis (LE2). The association of intrauterine infection with neurological morbidity remains controversial. Prolongation of latency, from gestational age at PPROM, is beneficial for the child (LE2).

CONCLUSION

PPROM is a major cause of prematurity and short- and long-term mortality and morbidity. Antenatal care is an important issue for obstetric and pediatric teams, aiming to reduce complications and adverse consequences for both mother and child.

Vaginal microbiome in early pregnancy and subsequent risk of spontaneous preterm birth: a case-control study

OBJECTIVES

To explore differences in the vaginal microbiome between preterm and term deliveries.

DESIGN

Nested case-control study in 3D cohort (design, develop, discover).

SETTING

Quebec, Canada.

SAMPLE

Ninety-four women with spontaneous preterm birth as cases [17 early (<34 weeks) and 77 late (34-36 weeks) preterm birth] and 356 women as controls with term delivery (≥37 weeks).

METHODS

To assess the vaginal microbiome by sequencing the V4 region of the 16S ribosomal RNA (rRNA) gene in swabs self-collected during early pregnancy.

MAIN OUTCOME MEASURES

Comparison of relative abundance of bacterial operational taxonomic units and oligotypes and identifying vaginal community state types (CSTs) in early or late spontaneous preterm and term deliveries.

RESULTS

Lactobacillus gasseri/ Lactobacillus johnsonii (coefficient -5.36, 95% CI -8.07 to -2.65), Lactobacillus crispatus (99%)/ Lactobacillus acidophilus (99%) (-4.58, 95% CI -6.20 to -2.96), Lactobacillus iners (99%)/ Ralstonia solanacearum (99%) (-3.98, 95% CI -6.48 to -1.47) and Bifidobacterium longum/ Bifidobacterium breve (-8.84, 95% CI -12.96 to -4.73) were associated with decreased risk of early but not late preterm birth. Six vaginal CSTs were identified: four dominated by Lactobacillus; one with presence of bacterial vaginosis-associated bacteria (Gardnerella vaginalis, Atopobium vaginae and Veillonellaceae bacterium) (CST IV); and one with nondominance of Lactobacillus (CST VI). CST IV was associated with increased risk of early (4.22, 95% CI 1.24-24.85) but not late (1.63, 95% CI 0.68-5.04) preterm birth, compared with CST VI.

CONCLUSIONS

Lactobacillus gasseri/L. johnsonii, L. crispatus/L. acidophilus, L. iners/R. solanacearum and B. longum/B. breve may be associated with decreased risk of early preterm birth. A bacterial vaginosis-related vaginal CST versus a CST nondominated by Lactobacillus may be associated with increased risk of early preterm birth.

TWEETABLE ABSTRACT

Largest study of its kind finds certain species of vaginal Lactobacillus + Bifidobacterium may relate to lower risk of preterm birth.

Gestational diabetes and risk of cardiovascular disease up to 25 years after pregnancy: a retrospective cohort study

AIMS

The risk of cardiovascular disease in women with gestational diabetes is poorly understood. We sought to determine whether gestational diabetes increases the risk of cardiovascular disease more than two decades after pregnancy.

METHODS

We carried out a retrospective cohort study of 1,070,667 women who delivered infants in hospitals within Quebec, Canada, between 1989 and 2013. We followed 67,356 women with gestational diabetes and 1,003,311 without gestational diabetes for a maximum of 25.2 years after the index delivery. The main outcome measures were hospitalization for ischemic heart disease, myocardial infarction, coronary angioplasty, coronary artery bypass graft, and other cardiovascular disorders. We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) comparing women with gestational diabetes to no gestational diabetes, adjusted for age, parity, socioeconomic deprivation, time period, and preeclampsia.

RESULTS

Women with gestational diabetes had a higher cumulative incidence of hospitalization for cardiovascular disease 25 years after delivery (190.8 per 1000 women) compared with no gestational diabetes (117.8 per 1000 women). Gestational diabetes was associated with a higher risk of ischemic heart disease (HR 1.23, 95% CI 1.12-1.36), myocardial infarction (HR 2.14, 95% CI 1.15-2.47), coronary angioplasty (HR 2.23, 95% CI 1.87-2.65), and coronary artery bypass graft (HR 3.16, 95% CI 2.24-4.47).

CONCLUSIONS

In this population of pregnant women, gestational diabetes was associated with an increased risk of heart disease 25 years after delivery. Women with gestational diabetes may merit closer monitoring for cardiovascular disease prevention after pregnancy.

Temporal trends of preterm birth in Shenzhen, China: a retrospective study

BACKGROUND

Preterm birth is the leading cause of child mortality under 5 years of age. Temporal trends in preterm birth rates are highly heterogeneous among countries and little information exists for China. To address this data gap, we investigated annual changes in preterm birth incidence rate and explored potential determinants of these changes in Shenzhen, China.

METHODS

A total of 1.4 million live births, during 2003-2012, were included from the Shenzhen birth registry. Negative-binominal regression models were used to estimate the annual percent changes in incidence. To identify the potential determinants behind temporal trends, we estimated the contribution of each changing risk factor to changes in rate by calculating the difference in population-attributable risk fraction.

RESULTS

Annual preterm birth incidence rates increased by 0.94% (95% CI 0.30%, 1.58%) overall, 3.60% (95% CI 2.73%, 4.48%) for medically induced, and 3.13% (95% CI 1.01%, 5.31%) for preterm premature rupture of membranes, but decreased by 2.34% (95% CI 1.62%, 3.06%) for spontaneous preterm labor. Higher maternal educational attainment (0.20 rate increase), lower proportion of inadequate prenatal care (0.15 rate reduction), more multipara (0.08 rate reduction), decreased proportion of preeclampsia or eclampsia (0.05 rate reduction), and larger proportion of young and older pregnant women (0.04 rate increase) were significant contributors to the overall change over time. Contributions of changing risk factors were different between preterm birth subtypes.

CONCLUSIONS

Preterm birth rate in Shenzhen, China increased overall during 2003-2012, although trends varied across three preterm birth subtypes. The rising rates were associated with changes in maternal education and age.

Gestational diabetes and the long-term risk of cataract surgery: A longitudinal cohort study

AIMS

We assessed the long-term risk of cataract following a pregnancy complicated by gestational diabetes.

METHODS

We carried out a longitudinal cohort study of 1,108,541 women who delivered infants between 1989-2013 in Quebec, Canada, with follow-up extending up to 25years later. The cohort included 71,862 women with gestational diabetes and 5247 with cataracts. We used Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of gestational diabetes with subsequent risk of cataract, adjusted for age, parity, socioeconomic status, time period, comorbidity, and type 2 diabetes.

RESULTS

Women with gestational diabetes had an elevated incidence of cataract (22.6 per 1000) compared with no gestational diabetes (15.1 per 1000), with 1.15 times the risk (95% CI 1.04-1.28). Women with gestational diabetes who subsequently developed type 2 diabetes had a higher risk of cataract compared with no gestational and type 2 diabetes (HR 3.62, 95% CI 3.01-4.35), but women with gestational diabetes who did not develop type 2 diabetes continued to be at risk (HR 1.12, 95% CI 1.00-1.25).

CONCLUSIONS

Gestational diabetes may be an independent risk factor for cataract later in life, although risks are greatest for women who subsequently develop type 2 diabetes.

Association of Maternal Preeclampsia With Infant Risk of Premature Birth and Retinopathy of Prematurity

Importance

Studies report conflicting associations between preeclampsia and retinopathy of prematurity (ROP). This study provides explanations for the discrepancies to clarify the relationship between preeclampsia and ROP.

Objective

To evaluate the association of maternal preeclampsia and risk of ROP among infants in an unrestricted birth cohort and a restricted subcohort of preterm, very low birth weight (P-VLBW) infants.

Design, Setting, and Participants

A retrospective review of 290 992 live births within the Intermountain Healthcare System in Utah from January 1, 2001, through December 31, 2010, was performed. Generalized estimating equations for logistic regressions with covariate adjustment were applied to relate ROP to preeclampsia among the full cohort and in a subcohort of P-VLBW infants born at younger than 31 weeks' gestation and weighing less than 1500 g.

Main Outcomes and Measures

The occurrence of ROP was related to maternal preeclampsia in the full cohort and in a subcohort of P-VLBW infants.

Results

In the full cohort, 51% of the infants were male and the mean (SD) gestational age was 38.38 (1.87) weeks. In the P-VLBW cohort, 55% were male and the mean (SD) gestational age was 26.87 (2.40) weeks. In the full cohort, preeclampsia was associated with an increased risk of all ROP (adjusted odds ratio [aOR], 2.46; 95% CI, 2.17-2.79; P < .001), severe ROP (aOR, 5.21; 95% CI, 3.44-7.91; P < .001), infant death (aOR, 1.66; 95% CI, 1.16-2.38; P = .006), and giving birth to a P-VLBW infant (aOR, 7.74; 95% CI, 6.92-8.67; P < .001). In the P-VLBW subcohort, preeclampsia was inversely associated with the development of all ROP (aOR, 0.79; 95% CI, 0.68-0.92; P = .003), severe ROP (aOR, 0.62; 95% CI, 0.36-1.06; P = .08), and infant death (aOR, 0.19; 95% CI, 0.11-0.32; P < .001).

Conclusions and Relevance

Preeclampsia was associated with an increased risk of developing ROP among an unrestricted cohort but with a reduced risk of ROP among a restricted subcohort of P-VLBW infants. Although the conflicting associations in the full and P-VLBW cohorts may reflect true differences, the association of a reduced risk of ROP among the P-VLBW subcohort also may reflect biases from restricting the cohort to prematurity, because prematurity is an outcome of preeclampsia.

Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Objective Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. Methods We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. Results A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Conclusion Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.

Variation in Maternal Co-morbidities and Obstetric Interventions across Area-Level Socio-economic Status: A Cross-Sectional Study

BACKGROUND

Multiple studies indicate a significant association between area-level socio-economic status (SES) and adverse maternal health outcomes; however, the impact of area-level SES on maternal co-morbidities and obstetric interventions has not been examined.

OBJECTIVE

To examine the variation in maternal co-morbidities and obstetric interventions across area-level SES.

METHODS

This study used data from the Discharge Abstract Database that comprised birth data in Alberta between 2005-2007 (n = 120 285). Co-morbidities and obstetric interventions were identified using validated case-definitions. Material deprivation index was obtained for each dissemination area through linkage of hospitalisation and census data. Multilevel logistic regression was used to analyse the data adjusting for potential confounding variables.

RESULTS

The prevalence of any co-morbidity varied across area-level SES. Drug abuse odds ratio (OR) 2.5 (95% confidence interval (CI) 1.8, 3.5), pre-existing diabetes OR 1.7 (95% CI 1.1, 2.6), and prolonged hospital stay OR 1.5 (95% CI 1.4, 1.6) were significantly more likely to occur in the most deprived areas compared to the least deprived areas. In contrast, caesarean delivery OR 0.9 (95% CI 0.8, 0.9) was less likely to occur in the most deprived areas compared to the least deprived areas. Area-level deprivation explained area-level variance of drug abuse, HIV, and other mental diseases only.

CONCLUSION

Many co-morbidities and obstetric interventions vary at the area-level, but only some are associated with area-level SES, and few of them vary due to the area-level SES. This indicates that other area-level factors, in addition to area-level SES, need to be considered when investigating maternal health and use of health interventions.

Preeclampsia and the risk of cataract extraction in life

BACKGROUND

Pregnancy-related risk factors for cataract are understudied, including the possibility that preeclampsia increases the risk of cataract later in life.

OBJECTIVE

We sought to evaluate the long-term risk of cataract extraction following a preeclamptic pregnancy.

STUDY DESIGN

We carried out a historic cohort study of 1,108,541 women who delivered at least 1 infant in any hospital in the province of Quebec, Canada, from 1989 through 2013, including 64,350 with preeclampsia and 5732 with cataract extractions. We categorized preeclampsia by onset time and severity, and followed up women for up to 25 years after delivery. We calculated the incidence of inpatient cataract extraction for women with and without preeclampsia, and used Cox proportional hazard models to estimate hazard ratios and 95% confidence intervals for later risk of cataract extraction, adjusting for age at first delivery, total parity, metabolic disease, asthma, socioeconomic deprivation, and time period.

RESULTS

Women with preeclampsia had a higher incidence of cataract extraction compared with no preeclampsia (21.0 vs 15.9/1000) and 1.20 times the risk (95% confidence interval, 1.08-1.34). Women with early-onset preeclampsia had 1.51 times the risk of cataract extraction compared with no preeclampsia (95% confidence interval, 1.14-2.00), whereas women with late-onset preeclampsia had 1.16 times the risk (95% confidence interval, 1.04-1.30). Risk was elevated by about 20% for both severe and mild preeclampsia. Preeclampsia with diabetes was associated with significantly greater risk (hazard ratio, 4.32; 95% confidence interval, 3.60-5.19).

CONCLUSION

Women with preeclampsia, particularly preeclampsia of early onset or with diabetes, may have greater risk of cataract later in life. The underlying pathways linking preeclampsia with cataract require further investigation.

Interpregnancy Interval and Adverse Perinatal Outcomes: A Record-Linkage Study Using the Manitoba Population Research Data Repository

OBJECTIVE

To examine the association between the interpregnancy interval (IPI) and preterm birth, low birth weight, and SGA birth in a developed country with universal health coverage.

METHODS

We conducted a secondary analysis of data housed at the Manitoba Centre for Health Policy. All live births in Manitoba hospitals over a 29-year period were identified and consecutive births to the same mother were grouped into sibling pairs to calculate the IPI for the younger siblings. Logistic regression models were fit to examine the association between the IPI and adverse perinatal outcomes, adjusted for potentially confounding sociodemographic and clinical factors.

RESULTS

In a cohort of more than 171 000 births and relative to IPIs of 18 to 23 months, IPIs shorter than 12 and longer than 23 months were associated with significantly increased odds of preterm birth overall and both medically indicated and spontaneous preterm births, low birth weight, and SGA birth. The strongest association observed was for intervals shorter than 6 months and spontaneous preterm birth (adjusted OR 1.83, 95% CI 1.65-2.03). When the outcome was modelled as GA categories, the strongest association observed was for intervals shorter than 6 months and early preterm birth (<34 weeks' GA; adjusted OR 2.47, 95% CI 2.07-2.94).

CONCLUSION

If the associations observed between the IPI and adverse perinatal outcomes in this large, population-based cohort are causal, birth spacing could form an important target of public health messaging in Canada.

The association between adverse pregnancy outcomes and maternal human papillomavirus infection: a systematic review protocol

BACKGROUND

Human papillomavirus (HPV) is the most prevalent genital infection, especially in young women of reproductive age. In vitro and animal model experiments provide compelling evidence of the harmful effect of HPV on pregnancy outcomes, but results from epidemiologic studies are inconclusive. We aim to determine the strength of the relationship between adverse pregnancy outcomes (APO) and HPV infection and assess its consistency across studies, by systematically reviewing the literature.

METHODS

The search strategy has been developed on the basis of the PICOS framework: Population (pregnant women); Exposure (HVP infection confirmed by HPV testing); Comparator (pregnant women without HPV infection); Outcomes (miscarriage, spontaneous preterm birth, low birth weight, preterm premature rupture of membranes, pregnancy-induced hypertensive disorders and intrauterine growth restriction) and Study design (observational studies). We will search three information sources: (1) electronic databases (MEDLINE, EMBASE, and EBM Reviews databases); (2) Grey literature (Google Scholar and Web of Science conference proceedings); and (3) citing and cited articles of included studies. Two reviewers (JN, NZ) will independently and in duplicate screen identified articles, select eligible studies, and extract data. Discrepancies will be resolved by consensus and otherwise by discussion with the other authors (MHM, HT). Quality of included studies will be assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. We will narratively synthesize extracted data whether meta-analysis is conducted or not. Meta-analysis of each outcome will be performed, and where appropriate, an average measure of association will be computed. We will use the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess and grade the strength of confidence in cumulative estimate.

DISCUSSION

Comprehensive and high-quality evidence of a negative effect of HPV on pregnancy outcomes might be an additional motivation for HPV vaccination. Absence of such relationship could dispel anxiety and reassure HPV-infected pregnant women and clinicians. Findings of a poor level of confidence will allow identification of current knowledge gaps on HPV-pregnancy outcome relationship that need further research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016033425.

Maternal Risk Factors for Preterm Birth in Murmansk County, Russia: A Registry-Based Study

BACKGROUND

Globally, about 11% of all liveborn infants are preterm. To date, data on prevalence and risk factors of preterm birth (PTB) in Russia are limited. The aims of this study were to estimate the prevalence of PTB in Murmansk County, Northwestern Russia and to investigate associations between PTB and selected maternal factors using the Murmansk County Birth Registry.

METHODS

We conducted a registry-based study of 52 806 births (2006-2011). In total, 51 156 births were included in the prevalence analysis, of which 3546 were PTBs. Odds ratios with 95% confidence intervals of moderate-to-late PTB, very PTB and extremely PTB for a range of maternal characteristics were estimated using multinomial logistic regression, adjusting for potential confounders.

RESULTS

The overall prevalence of PTB in Murmansk County was 6.9%. Unmarried status, prior PTBs, spontaneous and induced abortions were strongly associated with PTB at any gestational age. Maternal low educational level increased the risk of extremely and moderate-to-late PTB. Young (<18 years) or older (≥35 years) mothers, graduates of vocational schools, underweight, overweight/obese mothers, and smokers were at higher risk of moderate-to-late PTB. Secondary education, alcohol abuse, diabetes mellitus, or gestational diabetes were strongly associated with moderate-to-late and very PTB.

CONCLUSIONS

The observed prevalence of PTB (6.9%) in Murmansk County, Russia was comparable with data on live PTB from European countries. Adverse prior pregnancy outcomes, maternal low educational level, unmarried status, alcohol abuse, and diabetes mellitus or gestational diabetes were the most common risk factors for PTB.

Preterm preeclampsia in relation to country of birth

OBJECTIVE

To examine the association between maternal country of birth and the risk of preeclampsia+preterm birth (PTB).

STUDY DESIGN

We completed a population-based study in the entire province of Ontario, where there is universal access to obstetrical care. We included 881 700 singleton livebirths among Canadian-born mothers and 305 547 births among immigrant mothers. Adjusted risk ratios (aRRs) were adjusted for maternal age, parity and income quintile.

RESULTS

Compared with a rate of preeclampsia+PTB of 4.0 per 1000 among Canadian-born mothers, the aRR of preeclampsia+PTB at 24 to 36 weeks was significantly higher for immigrant women from Nigeria (1.79, 95% confidence interval (CI) 1.12 to 2.84), the Philippines (1.54, 95% CI 1.30 to 1.86), Colombia (1.68, 95% CI 1.04 to 2.73), Jamaica (2.06, 95% CI 1.66 to 2.57) and Ghana (2.12, 95% CI 1.40 to 3.21). The aRRs generally followed a similar pattern for secondary outcomes. Specifically, women from Ghana were at highest risk of preeclampsia+very PTB (4.55, 95% CI 2.57 to 8.06), and women from Jamaica at the highest risk of preeclampsia+indicated PTB (1.89, 95% CI 1.43 to 2.50).

CONCLUSION

The risk of preeclampsia+PTB is highest among women from a select number of countries. This information can enhance initiatives aimed at reducing the risk of PTB related to preeclampsia.

Born early and born poor: An eco-bio-developmental model for poverty and preterm birth

Poverty is associated with adverse long-term cognitive outcomes in children. Poverty is also linked with preterm delivery which, in turn, is associated with adverse cognitive outcomes. However, the extent of the effect of poverty on preterm delivery, as well as proposed mechanisms by which they occur, have not been well described. Further, the impact of poverty on preterm school readiness has not been reviewed. As the childhood poverty level continues to increase in the U.S., we examine the evidence around physiological, neurological, cognitive and learning outcomes associated with prematurity in the context of poverty. We use the evidence gathered to suggest an Eco-Bio-Developmental model, emphasizing poverty as a toxic stress which predisposes preterm birth and which, via epigenetic forces, can continue into the next generation. Continued postnatal social disadvantage for these developmentally high-risk preterm infants is strongly linked with poor neurodevelopmental outcomes, decreased school readiness, and decreased educational attainment which can perpetuate the poverty cycle. We suggest social remedies aimed at decreasing the impact of poverty on mothers, fathers, and children which may be effective in reducing the burden of preterm birth.

Maternal psychiatric disorders and risk of preterm birth

PURPOSE

To study the effect of maternal psychiatric disorders (depression, anxiety disorder, bipolar disease, schizophrenia, unspecified psychiatric disorder, and comorbid conditions) and odds of preterm birth.

METHODS

The Consortium on Safe Labor (2002-2008), an observational cohort with 12 centers from across the United States included 223,394 singleton pregnancies with clinical data obtained from electronic medical records and maternal diagnoses of psychiatric disorders from maternal discharge summaries. Length of gestation was based on the best clinical estimate and categorized as birth less than 39, less than 37, less than 34, and less than 28 weeks' gestation. The adjusted odds ratios (ORs) with 95% confidence intervals of birth were estimated by logistic regression with generalized estimating equations.

RESULTS

Any maternal psychiatric disorder was associated with odds of birth less than 39 weeks' gestation (odds ratio [OR] = 1.32, 95% confidence interval = 1.28-1.37), less than 37 weeks' gestation (OR = 1.45, 1.38-1.52), less than 34 weeks' gestation (OR = 1.47, 1.35-1.59), and less than 28 weeks' gestation (OR = 1.57, 1.36-1.82). Specifically, odds of birth less than 37 weeks' gestation were associated with maternal depression (OR = 1.31, 1.23-1.40), anxiety disorder (OR = 1.68, 1.41-2.01), depression with anxiety disorder (OR = 2.31, 1.93-2.78), bipolar disease (OR = 1.54, 1.22-1.94), bipolar disease with depression and/or anxiety disorder (OR = 1.70, 1.30-2.22), and unspecified psychiatric disorder (OR = 1.52, 1.41-1.64).

CONCLUSIONS

Maternal psychiatric disorders, especially comorbid psychiatric conditions, were associated with increased likelihood of preterm birth.

Association of maternal anemia with other risk factors in occurrence of Great obstetrical syndromes at university clinics, Kinshasa, DR Congo

BACKGROUND

Maternal anemia, a common situation in developing countries, provokes impairment of nutrients/oxygen supply to the placenta-fetus unit that leads to Great obstetrical syndromes (GOS). In our setting, however, occurrence of GOS has been found also depending on variables existing prior to pregnancy such as diabetes in family, hypertension in family, previous macrosomia, stillbirth, SGA and pre-eclampsia as well as overweight/obesity. Our study thus aimed to determine the magnitude of maternal anemia and its association with these pre-pregnancy high-risk variables in occurrence of GOS.

METHODS

This is a cross-sectional study including women delivered at the University Clinics of Kinshasa, DR Congo, 12. during 18 months. Anemia was stated at hemoglobin blood concentration < 10 g/dL. Sampled women were checked for pregnancy high-risk factors and pregnancy complications. Odds ratios (95% confidence intervals) were calculated to establish associations of anemia with various variables. Multivariate calculations aimed to isolate variables influencing these associations. The p <0.05 was considered significant.

RESULTS

The study sample included 412 women, among whom 220 (53.4%) were diagnosed anemic. Anemia was found significantly linked to malaria, urinary infection, cesarean section, prematurity, SGA and stillbirth whose risk was 1.6 - 6.1 times augmented. Anemia was also found linked to pre-pregnancy high-risk factors such as age < 18 and ≥ 35 years, previous miscarriage, grand multiparity, diabetes in family, previous prematurity, overweight/obesity, previous cesarean section and previous pre-eclampsia, all of them enhancing the link of maternal anemia with complications.

CONCLUSION

Maternal anemia is very prevalent among pregnant women of our setting. It strongly contributes to worsening of morbidities that act with pregnancy high-risk factors in raising the risk of cesarean section, prematurity, SGA and stillbirth.

Controlled direct effects of preeclampsia on neonatal health after accounting for mediation by preterm birth

BACKGROUND

Preeclampsia is characterized by alterations in angiogenic factors that may increase neonatal morbidity independent of preterm birth.

METHODS

We estimated the controlled direct effect of preeclampsia on neonatal outcomes independent of preterm birth among 200,103 normotensive and 10,507 preeclamptic singleton pregnancies in the Consortium on Safe Labor (2002-2008). Marginal structural models with stabilized inverse probability weights accounted for potential confounders in the pathway from preeclampsia to preterm birth to neonatal outcomes, including mediator-outcome confounders related to preeclampsia status, such as cesarean delivery. Controlled direct effects of preeclampsia on perinatal mortality, small for gestational age (SGA), neonatal intensive care unit (NICU) admission, respiratory distress syndrome, transient tachypnea of the newborn, anemia, apnea, asphyxia, peri- or intraventricular hemorrhage, and cardiomyopathy were estimated for the hypothesized intervention of term delivery for all infants.

RESULTS

When delivery was set at ≥37 weeks, preeclampsia increased the odds of perinatal mortality (odds ratio = 2.2 [95% confidence interval = 1.1-4.5], SGA = (1.9 [1.8-2.1]), NICU admission (1.9 [1.7-2.1]), respiratory distress syndrome (2.8 [2.0-3.7], transient tachypnea of the newborn (1.6 [1.3-1.9]), apnea (2.2 [1.6-3.1]), asphyxia (2.7 [1.5-4.9]), and peri- or intraventricular hemorrhage (3.2 [1.4-7.7]). No direct effect of preeclampsia at term was observed for anemia or cardiomyopathy. Our results appear robust in the presence of moderate confounding, and restriction to severe preeclampsia yielded similar findings.

CONCLUSION

Preeclampsia was directly associated with adverse neonatal outcomes beyond morbidity mediated by preterm birth. Although severe neonatal outcomes were less common at later gestational ages, marginal structural models suggested elevated neonatal risk due to preeclampsia even if it was possible to deliver all infants at term.

Factors associated with severe maternal morbidity and near miss in the São Francisco Valley, Brazil: a retrospective, cohort study

Background

Maternal mortality remains a major public health issue worldwide, with persistent high rates prevailing principally in underdeveloped countries. The objective of this study was to determine the risk factors for severe maternal morbidity and near miss (SMM/NM) in pregnant and postpartum women at the maternity ward of the Dom Malan Hospital, Petrolina, in northeastern Brazil.

Methods

A retrospective, cohort study was conducted to evaluate the sociodemographic and obstetric characteristics of the women. Patients who remained hospitalized at the end of the study period were excluded. Risk ratios (RR) and their respective 95% confidence intervals (95% CI) were calculated as a measure of relative risk. Hierarchical multiple logistic regression was also performed. Two-tailed p-values were used for all the tests and the significance level adopted was 5%.

Results

A total of 2,291 pregnant or postpartum women receiving care between May and August, 2011 were included. The frequencies of severe maternal morbidity and near miss were 17.5% and 1.0%, respectively. Following multivariate analysis, the factors that remained significantly associated with an increased risk of SMM/NM were a Cesarean section in the current pregnancy (OR: 2.6; 95% CI: 2.0 – 3.3), clinical comorbidities (OR: 3.4; 95% CI: 2.5 – 4.4), having attended fewer than six prenatal visits (OR: 1.1; 95% CI: 1.01 – 1.69) and the presence of the third delay (i.e. delay in receiving care at the health facility) (OR: 13.3; 95% CI: 6.7 – 26.4).

Conclusions

The risk of SMM/NM was greater in women who had been submitted to a Cesarean section in the current pregnancy, in the presence of clinical comorbidities, fewer prenatal visits and when the third delay was present. All these factors could be minimized by initiating a broad debate on healthcare policies, introducing preventive measures and improving the training of the professionals and services providing obstetric care.

Maternal haemoglobin and short-term neonatal outcome in preterm neonates

Objective

To determine whether there is a significant association between maternal haemoglobin measured before delivery and short-term neonatal outcome in very preterm neonates.

Study design

We included prospectively all live births occurring from 25 to 32+6 weeks of gestation in a tertiary care centre between January 1^st 2009 and December 31^st 2011. Outborn infants and infants presenting with lethal malformations were excluded. Three hundred and thirty-nine mothers and 409 infants met the inclusion criteria. For each mother-infant pair a prospective record of epidemiologic data was performed and maternal haemoglobin concentration recorded within 24 hours before delivery was retrospectively researched. Maternal haemoglobin was divided into quartiles with the second and the third one regarded as reference as they were composed of normal haemoglobin values. Short-term outcome was defined as poor in case of death during hospital stay and/or grades III/IV intraventricular haemorrhage and/or periventricular leukomalacia and/or necessity of ventriculoperitoneal shunt.

Results

The global rate of poor short-term neonatal outcome was 11.4% and was significantly associated with low maternal haemoglobin values. This association remained significant after adjustment for antenatal corticosteroids therapy, gestational age, parity, mechanism of preterm birth, mode of delivery and birth weight (aOR = 2.97 CI 95% [1.36–6.47]). There was no relation between short-term neonatal outcome and high maternal haemoglobin concentration values.

Conclusion

We show that low maternal haemoglobin concentration at delivery is an independent risk factor for poor short-term neonatal outcome in very preterm neonates. This study is one of the first to show such an association within the preterm population.

Healthcare expenses associated with multiple vs singleton pregnancies in the United States

OBJECTIVE

The purpose of this study was to document cost that is associated with multiple births vs singleton births in the United States.

STUDY DESIGN

This was a retrospective cohort study that used a claims database. Women 19-45 years old with live-born infants from 2005-2010 were identified. Infant deliveries were identified by International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes. The cost entailed all payment made by insurers and patients. For mothers, the cost included expenses from 27 weeks before delivery to 1 month after delivery. For infants, the cost contained all expenses until their first birthday. Adjusted cost was estimated by generalized linear models after adjustment for the potential confounding variables with a gamma distribution and a log link.

RESULTS

The analysis included 437,924 eligible deliveries. Of them, 97.02% were singletons; 2.85% were twins, and 0.13% was triplets or more. Women with multiple pregnancies had higher systemic and localized comorbidities compared with women with singleton pregnancies (P < .0001). Twins and triplets or more were more likely to have stayed in a neonatal intensive care unit than were singletons (P < .0001). On average, adjusted total all-cause health care cost was $21,458 (95% confidence interval [CI], $21,302-21,614) per delivery with singletons, $104,831 (95% CI, $103,402-106,280) with twins, and $407,199 (95% CI, $384,984-430,695) with triplets or more.

CONCLUSION

Pregnancies with the delivery of twins cost approximately 5 times as much when compared with singleton pregnancies; pregnancies with delivery of triplets or more cost nearly 20 times as much.

Effect of ambient temperature and air pollutants on the risk of preterm birth, Rome 2001-2010

INTRODUCTION

Although the prevalence of preterm births ranges from 5 to 13% and represents the leading cause of perinatal mortality and morbidity in developed countries, the etiology of preterm birth remains uncertain. We aimed to evaluate the effect of short-term exposure to high and low temperatures and air pollution on preterm delivery and to identify socio-demographic and clinical maternal risk factors enhancing individual susceptibility.

METHODS

We analyzed all singleton live births by natural delivery that occurred in Rome in 2001-2010. A time-series approach was used to estimate the effect of exposure to minimum temperature, maximum apparent temperature, heat waves, particulate matter with an aerodynamic diameter of 10μm or less (PM10), ozone, and nitrogen dioxide in the month preceding delivery; the analysis was conducted separately for cold and warm seasons. Socio-demographic and clinical risk factors were included as interaction terms.

RESULTS

Preterm births comprised nearly 6% of our cohort. An increase of 1.9% (95% confidence interval (CI) 0.86-2.87) in daily preterm births per 1°C increase in maximum apparent temperature in the 2days preceding delivery was estimated for the warm season. Older women, women with higher education levels, and women with obstetric or chronic pathologies reported during delivery had a lower effect of temperature on the risk of preterm birth, while women with a chronic disease in the two years before delivery and mothers<20years showed a higher effect. A +19% (95% CI 7.91-31.69) increase in preterm births was observed during heat waves. Temperature had no effect during the cold season. We detected a significant effect of PM10 on preterm-birth risk at a lag period of 12-22days during the warm season (+0.69%; 95% CI 0.23-1.15, for 1μg/m(3) increase of pollutant); women with obstetric pathologies and with a higher education level showed a higher risk.

CONCLUSIONS

Our results suggest a possible short-term effect of heat and a more delayed and prolonged effect of PM10 exposure on preterm-birth risk, as well as the existence of more susceptible subgroups of women. Our observations support the few reported investigations, and may help to increase awareness among public-health stakeholders and clinicians regarding the role of these environmental exposures as risk factors for premature birth and health consequences for children later in life.

Subtypes of preterm birth and the risk of postneonatal death

OBJECTIVE

To examine the differences in postneonatal death risk among 3 clinical subtypes of preterm birth: preterm premature rupture of membranes (PROM), indicated preterm birth, and spontaneous preterm labor.

STUDY DESIGN

We analyzed the 2001-2005 US linked birth/infant death (birth cohort) datasets. The preterm birth subtypes were classified using information on the birth certificate: reported PROM, induction of labor, cesarean section, and complications of pregnancy and labor. Cox proportional hazard models were used to estimate covariate-adjusted hazard ratios and 95% CIs for postneonatal death (from days 28 to 365). Estimation was given for preterm birth subtypes in a week-by-week analysis. Causes of death were analyzed by preterm birth subtype and then separately at 24-27, 28-31, and 32-36 weeks of gestation.

RESULTS

For the total of 1895350 singleton preterm births who survived the neonatal period, the postneonatal mortality rate was 1.11% for preterm PROM, 0.78% for indicated preterm birth, and 0.53% for spontaneous preterm labor. Preterm PROM was associated with significantly higher risk of postneonatal death compared with spontaneous preterm labor in infants born at 27 weeks gestation or later. Similarly, indicated preterm birth was associated with a significantly higher risk of postneonatal death than spontaneous preterm labor in infants born at 25 weeks gestation or later. Preterm PROM and indicated preterm birth were associated with greater risk of death in the postneonatal period compared with spontaneous preterm labor, irrespective of the cause of death.

CONCLUSION

Subtypes of preterm birth carry different risks of postneonatal mortality. Prevention of preterm-related postneonatal death may require more research into the root causes of preterm birth subtypes.