Risk of preterm birth among women using drugs during pregnancy with elevated α-fetoprotein

A Scoping Review of Preterm Birth Risk Factors

Preterm birth is a major cause of neonatal morbidity and mortality, but its etiology and risk factors are poorly understood. We undertook a scoping review to illustrate the breadth of risk factors for preterm birth that have been reported in the literature. We conducted a search in the PubMed database for articles published in the previous 5 years. We determined eligibility for this scoping review by screening titles and abstracts, followed by full-text review. We extracted odds ratios and other measures of association for each identified risk factor in the articles. A total of 2,509 unique articles were identified from the search, of which 314 were eligible for inclusion in our final analyses. We summarized risk factors and their relative impacts in the following categories: Activity, Psychological, Medical History, Toxicology, Genetics, and Vaginal Microbiome. Many risk factors for preterm birth have been reported. It is challenging to synthesize findings given the multitude of isolated risk factors that have been studied, inconsistent definitions of risk factors and outcomes, and use of different covariates in analyses. Novel methods of analyzing large datasets may promote a more comprehensive understanding of the etiology of preterm birth and ability to predict the outcome. KEY POINTS: · Preterm birth is difficult to predict.. · Preterm birth has many diverse risk factors.. · Holistic approaches may yield new insights..

Systematic Review: Polysubstance Prevalence Estimates Reported during Pregnancy, US, 2009-2020

INTRODUCTION

The objective of this systematic review is to describe polysubstance studies and their prevalence estimates among pregnant people in the US.

METHODS

This review was not subject to protocol preparation or registration with the International Prospective Register of Systematic Reviews (PROSPERO) because outcome data were not reported. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist was followed. Four scientific literature databases were used to identify articles published from January 1, 2009 to June 3, 2020 reporting prenatal exposure to two or more substances in the US. A standardized process of title and abstract screening followed by a two-phase full-text review was used to assess study eligibility.

RESULTS

A total of 119 studies were included: 7 case-control studies, 7 clinical trials, 76 cohort studies, and 29 cross-sectional studies. Studies varied with respect to study design, time period, region, sampling and participant selection, substances assessed, and method of exposure ascertainment. Commonly reported polysubstance prevalence estimates among studies of pregnant people included combinations with alcohol, marijuana, and/or tobacco/nicotine. The range of prevalence estimates was wide (alcohol 1-99%; marijuana 3-95%; tobacco/nicotine 2-95%).

DISCUSSION

Polysubstance use during pregnancy is common, especially with alcohol, marijuana, and/or tobacco/nicotine. Future research to assess polysubstance use during pregnancy could help better describe patterns and ultimately help mitigate its effects on maternal and infant health outcomes.

Genome-wide association study identifies a novel maternal gene × stress interaction associated with spontaneous preterm birth

BACKGROUND

Maternal stress is potentially a modifiable risk factor for spontaneous preterm birth (sPTB). However, epidemiologic findings on the maternal stress-sPTB relationship have been inconsistent.

METHODS

To investigate whether the maternal stress-sPTB associations may be modified by genetic susceptibility, we performed genome-wide gene × stress interaction analyses in 1490 African-American women from the Boston Birth cohort who delivered term (n = 1033) or preterm (n = 457) infants. Genotyping was performed using Illumina HumanOmni 2.5 array. Replication was performed using data from the NICHD genomic and Proteomic Network (GPN) for PTB research.

RESULTS

rs35331017, a T-allele insertion/deletion polymorphism in the protein-tyrosine phosphatase receptor Type D (PTPRD) gene, was the top hit that interacted significantly with maternal lifetime stress on risk of sPTB (P_G × E = 4.7 × 10^-8). We revealed a dose-responsive association between degree of stress and risk of sPTB in mothers carrying the insertion/insertion genotype, but an inverse association was observed in mothers carrying the heterozygous or deletion/deletion genotypes. This interaction was replicated in African-American (P_G × E = 0.088) and Caucasian mothers (P_G × E = 0.023) from the GPN study.

CONCLUSION

We demonstrated a significant maternal PTPRD × stress interaction on sPTB risk. This finding, if further confirmed, may provide new insight into individual susceptibility to stress-induced sPTB.

IMPACT

This was the first preterm study to demonstrate a significant genome-wide gene-stress interaction in African Americans, specifically, PTPRD gene variants can interact with maternal perceived stress to affect risk of spontaneous preterm birth. The PTPRD × maternal stress interaction was demonstrated in African Americans and replicated in both African Americans and Caucasians from the GPN study. Our findings highlight the importance of considering genetic susceptibility in assessing the role of maternal stress on spontaneous preterm birth.

Maternal anemia and pregnancy outcomes: a population-based study

OBJECTIVE

This study aims to describe adverse maternal and neonatal outcomes in women diagnosed with anemia in pregnancy.

STUDY DESIGN

This was a retrospective cohort study of California live births from 2007-2012, linked to maternal and infant hospital discharge records. Relative risks of adverse maternal and neonatal outcomes were calculated for women with and without anemia.

RESULTS

Anemic mothers were more likely to be diagnosed with hypertension, diabetes, placental abruption, or chorioamnionitis, or require a blood transfusion or admission to the intensive care unit (aRRs 1.2-6.8). Infants born to anemic mothers were more likely to be born preterm (8.9% versus 6.5%), but not more likely to suffer morbidities associated with prematurity.

CONCLUSION

In a population-based study, the diagnosis of anemia in pregnancy carries a higher risk of peri-partum, intra-partum, and post-partum complications for the mother, and a higher risk of preterm birth for the infant.