Prenatal alcohol consumption and placental outcomes: a systematic review and meta-analysis of clinical studies

Sex-specific alterations in cognitive control following moderate prenatal alcohol exposure and transient systemic hypoxia ischemia in the rat

BACKGROUND

Prenatal alcohol exposure (PAE) continues to be a worldwide problem. Affected offspring display impaired neurodevelopment, including difficulties with executive control. Although PAE has also been associated with decreased blood flow to fetuses, the relationship between PAE and altered blood flow is not well understood.

METHODS

We used preclinical models of PAE, transient systemic hypoxia ischemia (TSHI), and PAE + TSHI combined to assess the effects on neurodevelopmental outcomes using translationally relevant touchscreen operant platform testing. Twenty-eight Long-Evans (Blue Spruce, Strain HsdBlu:LE) dams were randomly assigned to one of four experimental groups: Saccharin Control (Sham), 5% Ethanol (PAE), TSHI, or 5% Ethanol and TSHI (PAE + TSHI). Dams consumed either saccharin or 5% ethanol during gestation. TSHI was induced on Embryonic Day 19 (E19) during an open laparotomy where the uterine arteries were transiently occluded for 1 h. Pups were born normally and, after weaning, were separated by sex. A total of 80 offspring, 40 males and 40 females, were tested on the 5-Choice Continuous Performance paradigm (5C-CPT).

RESULTS

Female offspring were significantly impacted by TSHI, but not PAE, with an increase in false alarms and a decrease in hit rates, omissions, accuracy, and correct choice latencies. In contrast, male offspring were mildly affected by PAE, but not TSHI, showing decreases in premature responses and increases in accuracy. No significant interactions between PAE and TSHI were detected on any measure.

CONCLUSION

Transient systemic hypoxia ischemia impaired performance on the 5C-CPT in females, leading to a bias toward stimulus responsivity regardless of stimulus type. In contrast, TSHI did not affect male offspring, and only slight effects of PAE were seen. Together, these data suggest that TSHI in females may cause alterations in cortical structures that override alterations caused by moderate PAE.

RNA-seq analysis reveals prenatal alcohol exposure is associated with placental inflammatory cells and gene expression

BACKGROUND

Fetal alcohol spectrum disorders (FASD) are the most common preventable cause of birth defects and neurodevelopmental disorders worldwide. The placenta is the crucial interface between mother and fetus. Prenatal alcohol exposure (PAE) has been shown to alter placental structure and expression of genes in bulk placental tissue samples, but prior studies have not examined effects on placental cell-type composition or taken cell-type into consideration in transcriptome analyses.

METHODS

We leveraged an existent placenta single-cell RNA-seq dataset to perform cell-type deconvolution of bulk placental RNA-seq data from 35 heavy drinking pregnant women and 33 controls in a prospective birth cohort in Cape Town, South Africa. We used bivariate analyses and multivariable adjusted linear regression models to assess the relation of PAE on inferred placental cell-type proportions. We also examined differential expression of inflammatory response genes and PAE, using multivariable adjusted linear models.

RESULTS

Deconvolution analyses showed heterogeneous placenta cell-type composition in which stromal (27 %), endothelial (26 %) and cytotrophoblasts (18 %) were the predominant cell-types. PAE around conception was associated with a higher proportion of Hofbauer cells (B = 0.51, p = 0.035) in linear models adjusted for maternal age, infant sex, and gestational age. Among the 652 inflammatory genes examined, 35 were differential expressed in alcohol exposed placentas (FDR p < 0.05).

CONCLUSIONS

Our findings suggest that heavy alcohol exposure during pregnancy can influence the proportion of fetal placental villi macrophages (Hofbauer cells) and increased expression of inflammatory genes. Future studies are needed to further characterize these effects and to assess the potential functional roles of placental inflammation in FASD.

Factors and outcomes for placental anomalies: An umbrella review of systematic reviews and meta-analyses

Background

Placental anomalies, including placenta previa (PP), placenta accreta spectrum disorders (PAS), and vase previa (VP), are associated with several adverse foetal-neonatal and maternal complications. However, there is still a lack of robust evidence on the pathogenesis and adverse outcomes of the diseases. Through this umbrella review, we aimed to systematically review existing meta-analyses exploring the factors and outcomes for pregnancy women with placental anomalies.

Methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library from inception to February 2023. We used AMSTAR 2 to assess the quality of the reviews and estimated the pooled risk and 95% confidence intervals (CIs) for each meta-analysis.

Results

We included 34 meta-analyses and extracted 55 factors (27 for PP, 22 for PAS, and 6 for VP) and 16 outcomes (12 for PP, and 4 for VP) to assess their credibility. Seven factors (maternal cocaine use (for PP), uterine leiomyoma (for PP), prior abortion (spontaneous) (PP), threatened miscarriage (PP), maternal obesity (PP), maternal smoking (PAS), male foetus (PAS)) had high epidemiological evidence. Twelve factors and six outcomes had moderate epidemiological evidence. Twenty-two factors and eight outcomes showed significant association, but with weak credibility.

Conclusions

We found varying levels of evidence for placental anomalies of different factors and outcomes in this umbrella review.

Registration

PROSPERO: CRD42022300160.

Vulnerabilities and reparative strategies during pregnancy, childbirth, and the postpartum period: moving from rhetoric to action

Maternal outcomes throughout pregnancy, childbirth, and the postnatal period are influenced by interlinked and interdependent vulnerabilities. A comprehensive understanding of how various threats and barriers affect maternal and perinatal health is critical to plan, evaluate and improve maternal health programmes. This paper builds on the introductory paper of the Series on the determinants of maternal health by assessing vulnerabilities during pregnancy, childbirth, and the postnatal period. We synthesise and present the concept of vulnerability in pregnancy and childbirth, and map vulnerability attributes and their dynamic influence on maternal outcomes in early and late pregnancy and during childbirth and the postnatal period, with a particular focus on low-income and middle-income countries (LMICs). We summarise existing literature and present the evidence on the effects of various reparative strategies to improve pregnancy and childbirth outcomes. Lastly, we discuss the implications of the identified vulnerability attributes and reparative strategies for the efforts of policymakers, healthcare professionals, and researchers working towards improving outcomes for women and birthing people in LMICs.

Alcohol exposure before and during pregnancy is associated with reduced fetal growth: the Safe Passage Study

BACKGROUND

Prenatal alcohol exposure (PAE) is a worldwide public health concern. While PAE is known to be associated with low birth weight, little is known about timing and quantity of PAE on fetal growth. This study investigated the association between periconceptional and prenatal alcohol exposure and longitudinal fetal growth, focusing on timing and quantity in a high exposure cohort.

METHODS

The Safe Passage Study was a prospective cohort study, including 1698 pregnant women. Two-dimensional transabdominal ultrasound examinations were performed to measure fetal femur length, abdominal and head circumference, and biparietal diameter, at three time points during pregnancy. Estimated fetal weight and Z-scores of all parameters were calculated. Trimester-specific alcohol exposure was assessed using the Timeline Followback method. To investigate the associations of specific timing of PAE and fetal growth, two models were built. One with alcohol exposure as accumulative parameter over the course of pregnancy and one trimester specific model, in which PAE was separately analyzed. Linear mixed models adjusted for potential confounders were applied with repeated assessments of both alcohol exposure and fetal growth outcomes.

RESULTS

This study demonstrated that periconceptional and prenatal alcohol exposure were associated with reduced fetal growth. Effect sizes are displayed as estimated differences (ED) in Z-score and corresponding 95% confidence intervals (95% CIs). When investigated as accumulative parameter, PAE was related to a smaller femur length (ED30; - 0.13 (95% CI; - 0.22; - 0.04), ED36; - 0.14 (95% CI; - 0.25; - 0.04)) and a smaller abdominal circumference (ED36; - 0.09 (95% CI; - 0.18; - 0.01)). Periconceptional alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.14 (95% CI; - 0.25; - 0.02), ED36; - 0.22 (95% CI; - 0.37; - 0.06)) and a smaller estimated fetal weight (ED36; - 0.22 (95% CI; - 0.38; - 0.05)). Second trimester alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.49 (95% CI; - 0.86; - 0.12), ED36; - 0.70 (95% CI; - 1.22; - 0.17)) and estimated fetal weight (ED30; - 0.54 (95% CI; - 0.94; - 0.14), ED36; - 0.69 (95% CI; - 1.25; - 0.14)). No additional association of binge drinking was found besides the already observed association of PAE and fetal growth.

CONCLUSIONS

This study demonstrated that PAE negatively affects fetal growth, in particular when exposed during the periconception period or in second trimester. Our results indicate that potential negative consequences of PAE are detectable already before birth. Therefore, healthcare providers should actively address and discourage alcohol use during pregnancy.

Associations between the maternal healthy lifestyle score and its individual components during early pregnancy with placental outcomes

INTRODUCTION

The influence of maternal lifestyle behaviours on placental growth have been investigated individually, but with conflicting results, and their combined effect is under-researched. Therefore, we examined associations between a composite maternal healthy lifestyle score (HLS), and its individual components, during early pregnancy with placental outcomes.

METHODS

Participants included Lifeways Cross-Generational Cohort mother-child pairs (n = 202). A composite HLS based on a less inflammatory diet (bottom 40% of the energy-adjusted Dietary Inflammatory Index (E-DII™)), moderate-to-vigorous physical activity (MVPA), healthy pre-pregnancy BMI (18.5-24.9 kg/m²), never smoking, and non-/moderate alcohol intake was calculated. Quantile regression analysed HLS (and individual components) associations with measures of placental development (untrimmed placental weight (PW)) and function (birth weight:placental weight (BW:PW) ratio) at the 10th, 25th, 50th, 75th and 90th centiles.

RESULTS

A more pro-inflammatory diet was positively, and smoking and heavy alcohol consumption were negatively, associated with PW at median centiles (B: 41.97 g, CI: 3.71, 80.22, p < 0.05; B: -58.51 g, CI: -116.24, -0.77, p < 0.05; B: -120.20 g, CI: -177.97, -62.43, p < 0.05 respectively). Low MVPA was inversely associated with BW:PW ratio at the 10th and 90th centiles (B: -0.36, CI: -0.132, -0.29, p < 0.01 and B: -0.45, CI: -0.728, -0.182, p < 0.01, respectively). Heavy alcohol intake was positively associated with BW:PW ratio at the 10th centile (B: 0.54, CI: 0.24, 0.85, p < 0.01). Results of sex-stratified analysis provide evidence of sexual dimorphism.

DISCUSSION

Associations of certain lifestyle factors, but not the composite HLS, during early pregnancy with measures of placental development (PW) and function (BW:PW ratio) varied by quantiles and by sex.

The role of maternal choline, folate and one-carbon metabolism in mediating the impact of prenatal alcohol exposure on placental and fetal development

Prenatal alcohol consumption (PAE) may be associated with a broad spectrum of impacts, ranging from no overt effects, to miscarriage, fetal growth restriction and fetal alcohol spectrum disorder. A major mechanism underlying the effects of PAE is considered to be altered DNA methylation and gene expression. Maternal nutritional status may be an important factor in determining the extent to which PAE impacts pregnancy outcomes, particularly the dietary micronutrients folate and choline because they provide methyl groups for DNA methylation via one carbon metabolism. This review summarises the roles of folate and choline in development of the blastocyst, the placenta and the fetal brain, and examines the evidence that maternal intake of these micronutrients can modify the effects of PAE on development. Studies of folate or choline deficiency have found reduced blastocyst development and implantation, reduced placental invasion, vascularisation and nutrient transport capability, impaired fetal brain development, and abnormal neurodevelopmental outcomes. PAE has been shown to reduce absorption and/or metabolism of folate and choline and to produce similar outcomes to maternal choline/folate deficiency. A few studies have demonstrated that the effects of PAE on brain development can be ameliorated by folate or choline supplementation; however, there is very limited evidence on the effects of supplementation in early pregnancy on the blastocyst and placenta. Further studies are required to support these findings and to determine optimal supplementation parameters.

Fetal alcohol spectrum disorders

Alcohol readily crosses the placenta and may disrupt fetal development. Harm from prenatal alcohol exposure (PAE) is determined by the dose, pattern, timing and duration of exposure, fetal and maternal genetics, maternal nutrition, concurrent substance use, and epigenetic responses. A safe dose of alcohol use during pregnancy has not been established. PAE can cause fetal alcohol spectrum disorders (FASD), which are characterized by neurodevelopmental impairment with or without facial dysmorphology, congenital anomalies and poor growth. FASD are a leading preventable cause of birth defects and developmental disability. The prevalence of FASD in 76 countries is >1% and is high in individuals living in out-of-home care or engaged in justice and mental health systems. The social and economic effects of FASD are profound, but the diagnosis is often missed or delayed and receives little public recognition. Future research should be informed by people living with FASD and be guided by cultural context, seek consensus on diagnostic criteria and evidence-based treatments, and describe the pathophysiology and lifelong effects of FASD. Imperatives include reducing stigma, equitable access to services, improved quality of life for people with FASD and FASD prevention in future generations.

Heavy prenatal alcohol exposure and obstetric and birth outcomes: a Danish nationwide cohort study from 1996 to 2018

BACKGROUND

Heavy alcohol use during pregnancy can harm the fetus, but the relation to most obstetric outcomes remains unclear. We therefore aimed to describe maternal characteristics and estimate the association between heavy prenatal alcohol exposure and 22 adverse obstetric and birth outcomes.

METHODS

We carried out a Danish nationwide register-based historical cohort study, including all singleton births from Jan 1, 1996, to Dec 31, 2018. Births of women who had emigrated to Denmark were excluded from the study due to missing data and women who migrated within 1 year before or during pregnancy were also excluded due to loss to follow-up. Data were extracted from the Danish Medical Birth Register, the Danish National Patient Registry, the Danish National Prescription Registry, the Danish Civil Registration System, and the Population Education Register. Logistic regression models were used to estimate crude and adjusted odds ratios (ORs) of obstetric and birth outcomes. Heavy alcohol use was defined by hospital contacts for alcohol-attributable diagnoses given to the mother, her infant, or both, or maternal redeemed prescriptions for drugs to treat alcohol dependence within 1 year before or during pregnancy.

FINDINGS

Of 1 191 295 included births, 4823 (0·40%) were defined as heavily alcohol-exposed and 1 186 472 were categorised as a reference group with no identified heavy prenatal alcohol exposure. Heavy-alcohol-exposed births more often had mothers with psychiatric diagnoses (49·8% vs 9·6%), substance use (22·0% vs 0·4%), tobacco use (64·3% vs 15·8%), and low educational level (64·1% vs 17·6%) than did the reference group. For heavy-alcohol-exposed births, significantly increased adjusted ORs were found for small for gestational age (OR 2·20 [95% CI 1·97-2·45]), preterm birth (OR 1·32 [1·19-1·46]), haemorrhage in late pregnancy (OR 1·25 [1·05-1·49]), and preterm prelabour rupture of membranes (OR 1·18 [1·00-1·39]). Decreased adjusted ORs were found for postpartum haemorrhage (500-999 mL; OR 0·80 [95% CI 0·69-0·93]), gestational diabetes (OR 0·81 [0·67-0·99]), planned caesarean section (OR 0·82 [0·72-0·94]), pre-eclampsia and eclampsia (OR 0·83 [0·71-0·96]), and abnormalities of forces of labour (OR 0·92 [0·86-0·99]).

INTERPRETATION

Heavy prenatal alcohol exposure is associated with adverse obstetric and birth outcomes and high proportions of maternal low educational level, psychiatric disease, and lifestyle risk behaviours. These findings highlight a need for holistic public health programmes and policy attention on improving pre-conceptional care and antenatal care.

FUNDING

The Obel Family Foundation, The Health Foundation, TrygFonden, Aase and Ejnar Danielsens Foundation, The North Denmark Region Health Science and Research Foundation, Holms Memorial Foundation, Dagmar Marshalls Foundation, the A.P. Møller Foundation, King Christian X Foundation, Torben and Alice Frimodts Foundation, the Axel and Eva Kastrup-Nielsens Foundation, the A.V. Lykfeldts Foundation.

Epigenetics as a Biomarker for Early-Life Environmental Exposure

PURPOSE OF REVIEW

There is interest in evaluating the developmental origins of health and disease (DOHaD) which emphasizes the role of prenatal and early-life environments on non-communicable health outcomes throughout the life course. The ability to rigorously assess and identify early-life risk factors for later health outcomes, including those with childhood onset, in large population samples is often limited due to measurement challenges such as impractical costs associated with prospective studies with a long follow-up duration, short half-lives for some environmental toxicants, and lack of biomarkers that capture inter-individual differences in biologic response to external environments.

RECENT FINDINGS

Epigenomic patterns, and DNA methylation in particular, have emerged as a potential objective biomarker to address some of these study design and exposure measurement challenges. In this article, we summarize the literature to date on epigenetic changes associated with specific prenatal and early-life exposure domains as well as exposure mixtures in human observational studies and their biomarker potential. Additionally, we highlight evidence for other types of epigenetic patterns to serve as exposure biomarkers. Evidence strongly supports epigenomic biomarkers of exposure that are detectable across the lifespan and across a range of exposure domains. Current and future areas of research in this field seek to expand these lines of evidence to other environmental exposures, to determine their specificity, and to develop predictive algorithms and methylation scores that can be used to evaluate early-life risk factors for health outcomes across the life span.

Iterative delivery of an implementation support package to increase and sustain the routine provision of antenatal care addressing alcohol consumption during pregnancy: study protocol for a stepped-wedge cluster trial

INTRODUCTION

Antenatal care addressing alcohol consumption during pregnancy is not routinely delivered in maternity services. Although a number of implementation trials have reported significant increases in such care, the majority of women still did not receive all recommended care elements, and improvements dissipated over time. This study aims to assess the effectiveness of an iteratively developed and delivered implementation support package in: (1) increasing the proportion of pregnant women who receive antenatal care addressing alcohol consumption and (2) sustaining the rate of care over time.

METHODS AND ANALYSIS

A stepped-wedge cluster trial will be conducted as a second phase of a previous trial. All public maternity services within three sectors of a local health district in Australia will receive an implementation support package that was developed based on an assessment of outcomes and learnings following the initial trial. The package will consist of evidence-based strategies to support increases in care provision (remind clinicians; facilitation; conduct educational meetings) and sustainment (develop a formal implementation blueprint; purposely re-examine the implementation; conduct ongoing training). Measurement of outcomes will occur via surveys with women who attend antenatal appointments each week. Primary outcomes will be the proportion of women who report being asked about alcohol consumption at subsequent antenatal appointments; and receiving complete care (advice and referral) relative to alcohol risk at initial and subsequent antenatal appointments. Economic and process evaluation measures will also be reported.

ETHICS AND DISSEMINATION

Ethical approval was obtained through the Hunter New England (16/11/16/4.07, 16/10/19/5.15) and University of Newcastle Human Research Ethics Committees (H-2017-0032, H-2016-0422) and the Aboriginal Health and Medical Research Council (1236/16). Trial findings will be disseminated to health service decision makers to inform the feasibility of conducting additional cycles to further improve antenatal care addressing alcohol consumption as well as at scientific conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials Registry (ACTRN12622000295741).

Current Resources for Evidence-Based Practice, March 2022

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of systemic racism and its effect on maternal health in the United States and commentaries on reviews focused on barriers and facilitators to HPV vaccination and delayed cord clamping in preterm infants.

The Pivotal Role of the Placenta in Normal and Pathological Pregnancies: A Focus on Preeclampsia, Fetal Growth Restriction, and Maternal Chronic Venous Disease

The placenta is a central structure in pregnancy and has pleiotropic functions. This organ grows incredibly rapidly during this period, acting as a mastermind behind different fetal and maternal processes. The relevance of the placenta extends far beyond the pregnancy, being crucial for fetal programming before birth. Having integrative knowledge of this maternofetal structure helps significantly in understanding the development of pregnancy either in a proper or pathophysiological context. Thus, the aim of this review is to summarize the main features of the placenta, with a special focus on its early development, cytoarchitecture, immunology, and functions in non-pathological conditions. In contraposition, the role of the placenta is examined in preeclampsia, a worrisome hypertensive disorder of pregnancy, in order to describe the pathophysiological implications of the placenta in this disease. Likewise, dysfunction of the placenta in fetal growth restriction, a major consequence of preeclampsia, is also discussed, emphasizing the potential clinical strategies derived. Finally, the emerging role of the placenta in maternal chronic venous disease either as a causative agent or as a consequence of the disease is equally treated.