Folic acid antagonist use before and during pregnancy and risk for selected birth defects

The Safety of Alcohol Pharmacotherapies in Pregnancy: A Scoping Review of Human and Animal Research

BACKGROUND AND OBJECTIVE

Alcohol pharmacotherapies pose unknown teratogenic risks in pregnancy and are therefore recommended to be avoided. This limits treatment options for pregnant individuals with alcohol use disorders (AUD). The information on the safety of these medications during pregnancy is uncertain, prompting a scoping review. The objective of this review was to investigate available information on the safety of alcohol pharmacotherapies in pregnancy.

METHODS

Studies published between January 1990 and July 2023 were identified through searches in BIOSIS, Embase, PsycINFO and MEDLINE databases, using terms related to pregnancy and alcohol pharmacotherapies. The alcohol pharmacotherapies investigated were naltrexone, acamprosate, disulfiram, nalmefene, baclofen, gabapentin and topiramate. Studies were screened by two independent reviewers. Covidence software facilitated the management, screening and extraction of studies.

RESULTS

A total of 105 studies were included in the review (naltrexone: 21, acamprosate: 4, disulfiram: 3, baclofen: 3, nalmefene: 0, topiramate: 55, gabapentin: 32) with some studies investigating multiple medications. Studies investigating naltrexone's safety in pregnancy focussed on opioid use disorders, with limited evidence regarding its safety in the context of AUD. Despite concerns about higher rates of some pregnancy complications, studies generally indicate naltrexone as a safer option compared with opioid agonists or alcohol during pregnancy. Acamprosate was not clearly associated with adverse effects of exposure in pregnancy, with two pre-clinical studies suggesting potential neuroprotective properties. Disulfiram has a high risk of congenital anomalies when used in pregnancy, believed to be due to its mechanism of action. Prenatal topiramate has also been associated with an increased risk of congenital anomalies, particularly oral clefts. There were mixed results concerning the safety of prenatal gabapentin and little to no literature investigating the safety of baclofen or nalmefene during pregnancy.

CONCLUSIONS

There is insufficient research on the safety of alcohol pharmacotherapies in pregnancy. Despite this, given alcohol's teratogenic effects, naltrexone could be considered to help maintain abstinence in pregnant individuals with AUD, particularly when psychosocial treatments have failed.

The Methodological Quality of Observational Studies Examining the Risk of Pregnancy Drug Use on Congenital Malformations Needs Substantial Improvement: A Cross-Sectional Survey

BACKGROUND AND OBJECTIVE

An increasing number of observational studies have investigated the risk of using drugs during pregnancy on congenital malformations. However, the credibility of the causal relationships drawn from these studies remains uncertain. This study aims to evaluate the potential methodological issues in existing observational studies.

METHODS

We used a stepwise approach to investigate this issue. First, we identified observational studies published in 2020 that examined the risk of congenital malformations associated with medication use during pregnancy. We assessed the methodological characteristics for establishing causality, including study design, confounding control, and sensitivity analysis, and compared them between "core clinical journals" and "general journals." For studies reporting an increased risk of congenital malformations in core clinical journals, we searched for subsequent studies addressing the same research question published between January 2021 and May 2023 to assess the consistency of the literature.

RESULTS

A total of 40 eligible studies were published in 2020, primarily focused on the safety of vitamin B12 and folic acid (n = 4), antidepressants (n = 4), and others (n = 32). Our findings suggest that only two (5.00%) studies used causal models to guide the identification of confounding, and only eight (20.00%) studies assessed the potential dose-response relationship. In all, 15 (37.50%) studies used propensity score analysis strategy to achieve "mimic-randomization." In addition, 22 studies (55.00%) performed sensitivity analyses, while 10 (45.45%) showed inconsistency with the primary outcome. Furthermore, 5 studies reported positive outcomes, whereas only 1 out of 11 studies demonstrated a positive correlation between drug usage during pregnancy and major malformations in subsequent studies.

CONCLUSION

A significant portion of the studies has failed to sufficiently consider the essential methodological characteristics required to improve the credibility of causal inferences. The increased risk of congenital malformations documented in core clinical journal was not adequately replicated in subsequent studies.

Maternal exposure to folate antagonists and susceptibility to congenital heart disease in offspring: A systematic review and meta-analysis

AIMS

The objective of this meta-analysis was to determine whether maternal exposure to folate antagonists is associated with increased rates of congenital heart disease in offspring.

METHODS

A comprehensive search for articles in the MEDLINE (PubMed) and EMBASE databases published up to 21 August 2023 was performed. The search strategy was not limited by study design but only for articles in the English language.

RESULTS

Analysis of 6 cohort studies and 5 cross-sectional studies, published between 1976 and 2020, showed significant increase in rate of congenital heart disease (odds ratio 1.55, 95% confidence interval, 1.28-1.87) when exposed to folate antagonists compared with the control. Further subgroup analysis showed the increased rate for exposure to both dihydrofolate reductase inhibitors and antiepileptic drugs separately. No differences were observed when analyses were stratified by timing of study.

CONCLUSION

Administration of folate antagonists within the 12-week period preceding conception and throughout the second and third months of gestation exhibited a statistically significant elevation in the susceptibility to congenital heart diseases. Notably, the protective effect of folic acid supplementation was reported in cases of congenital heart disease linked to dihydrofolate reductase inhibitors but not that associated with antiepileptic drugs.

Advances in Fetal Surgical Repair of Open Spina Bifida

Spina bifida remains a common congenital anomaly of the central nervous system despite national fortification of foods with folic acid, with a prevalence of 2-4 per 10,000 live births. Prenatal screening for the early detection of this condition provides patients with the opportunity to consider various management options during pregnancy. Prenatal repair of open spina bifida, traditionally performed by the open maternal-fetal surgical approach through hysterotomy, has been shown to improve outcomes for the child, including decreased need for cerebrospinal fluid diversion surgery and improved lower neuromotor function. However, the open maternal-fetal surgical approach is associated with relatively increased risk for the patient and the overall pregnancy, as well as future pregnancies. Recent advances in minimally invasive prenatal repair of open spina bifida through fetoscopy have shown similar benefits for the child but relatively improved outcomes for the pregnant patient and future childbearing.

Multifactorial Rare Diseases: Can Uncertainty Analysis Bring Added Value to the Search for Risk Factors and Etiopathogenesis?

Uncertainty analysis is the process of identifying limitations in knowledge and evaluating their implications for scientific conclusions. Uncertainty analysis is a stable component of risk assessment and is increasingly used in decision making on complex health issues. Uncertainties should be identified in a structured way and prioritized according to their likely impact on the outcome of scientific conclusions. Uncertainty is inherent to the rare diseases (RD) area, where research and healthcare have to cope with knowledge gaps due to the rarity of the conditions; yet a systematic approach toward uncertainties is not usually undertaken. The uncertainty issue is particularly relevant to multifactorial RD, whose etiopathogenesis involves environmental factors and genetic predisposition. Three case studies are presented: the newly recognized acute multisystem inflammatory syndrome in children and adolescents associated with SARS-CoV-2 infection; the assessment of risk factors for neural tube defects; and the genotype-phenotype correlation in familial Mediterranean fever. Each case study proposes the initial identification of the main epistemic and sampling uncertainties and their impacts. Uncertainty analysis in RD may present aspects similar to those encountered when conducting risk assessment in data-poor scenarios; therefore, approaches such as expert knowledge elicitation may be considered. The RD community has a main strength in managing uncertainty, as it proactively develops stakeholder involvement, data sharing and open science. The open science approaches can be profitably integrated by structured uncertainty analysis, especially when dealing with multifactorial RD involving environmental and genetic risk factors.