Bariatric surgery and the risk of congenital anomalies in subsequent pregnancies

Second-trimester abortion and risk of live birth

BACKGROUND

Second-trimester abortion may result in a live birth, but the extent to which this outcome occurs is unknown.

OBJECTIVE

This study aimed to examine rates of live birth after pregnancy termination in the second trimester and identify associated risk factors.

STUDY DESIGN

We conducted a retrospective cohort study of 13,777 second-trimester abortions occurring in hospital settings between April 1, 1989 and March 31, 2021 in Quebec, Canada. The exposure was induced abortion between 15 and 29 weeks of gestation, including the indication for (fetal anomaly, maternal emergency, other) and use of feticidal injection (intracardiac/intrathoracic or intraamniotic). The primary outcome was live birth following abortion. We measured the rate of live birth per 100 abortions and used adjusted log-binomial regression models to estimate risk ratios and 95% confidence intervals for the association of fetal and maternal characteristics with the risk of live birth. We assessed the extent to which feticidal injection reduced the risk.

RESULTS

Among 13,777 abortions between 15 and 29 weeks of gestation, 1541 (11.2%) led to live birth. Fetal anomaly was a common indication for termination (48.1%), and most abortions were by labor induction (72.2%). Compared with abortion between 15 and 19 weeks, abortion between 20 and 24 weeks was associated with 4.80 times the risk of live birth (95% confidence interval, 4.20-5.48), whereas abortion between 25 and 29 weeks was associated with 1.34 times the risk (95% confidence interval, 1.00-1.79). Feticidal injection reduced the risk of live birth by 57% compared with no injection (risk ratio, 0.43; 95% confidence interval, 0.36-0.51). Intracardiac or intrathoracic injection was particularly effective at preventing live birth (risk ratio, 0.02; 95% confidence interval, 0.01-0.07).

CONCLUSION

Second-trimester abortion carries a risk of live birth, especially at 20 to 24 weeks of gestation, although feticidal injection may protect against this outcome.

Beyond Weight Loss: A Comprehensive Review of Pregnancy Management following Bariatric Procedures

The increasing prevalence of bariatric surgery among women of childbearing age raises critical questions about the correct management of pregnancy following these procedures. This literature review delves into the multifaceted considerations surrounding pregnancy after bariatric surgery, with a particular focus on the importance of preconception counselling, appropriate nutrition assessment, and the necessity of correct folic acid supplementation. Key areas of investigation include nutrient absorption challenges, weight gain during pregnancy, and potential micronutrient deficiencies. Examining the relationship between bariatric surgery and birth defects, particularly heart and musculoskeletal issues, uncovers a twofold increase in risk for women who underwent surgery before pregnancy, with the risk emphasized before folic acid fortification. In contrast, a nationwide study suggests that infants born to mothers with bariatric surgery exhibit a reduced risk of major birth defects, potentially associated with improved glucose metabolism. In addition, this review outlines strategies for managing gestational diabetes and other pregnancy-related complications in individuals with a history of bariatric surgery. By synthesizing existing literature, this paper aims to provide healthcare providers with a comprehensive framework for the correct management of pregnancy in this unique patient population, promoting the health and well-being of both mother and child.

Medical and Psychological Aspects of Pregnancy in Women with Obesity and after Bariatric Surgery

Chronic diseases are potential risk factors for pregnancy duration and neonatal outcomes. This narrative review aimed to summarize the research results on the specifics of pregnancy in women with obesity and after bariatric surgery. PubMed and Google Scholar databases were searched. Systematic reviews, meta-analyses, clinical trials, and references to identified articles from the last ten years (2013-2023) were included. Ultimately, 107 literature items were qualified. It has been shown that women with obesity planning pregnancy should reduce their body weight because obesity is a risk factor for adverse obstetric and neonatal outcomes. Bariatric surgery effectively reduces excessive body weight and the health risks in women with obesity during pregnancy and their offspring. However, at least a year interval between surgery and conception is recommended. An interdisciplinary medical team should provide patient care during pregnancy with knowledge and skills related to people after bariatric surgery. Due to the increased risk of mental disorders, especially depression, it is necessary to constantly monitor the mental state of women and provide psychological support and education on a healthy lifestyle during pregnancy and the postpartum period.

Association between First Trimester Exposure to Ambient PM2.5 and NO2 and Congenital Heart Defects: A Population-Based Cohort Study of 1,342,198 Live Births in Canada

BACKGROUND

The extent to which ambient air pollution contributes to the pathogenesis of congenital heart defects remains uncertain.

OBJECTIVE

We investigated whether first trimester exposure to ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2) was associated with the risk of critical and noncritical heart defects in a large population-based cohort of births.

METHODS

We carried out a retrospective cohort study of children conceived between 2000 and 2016 in Quebec, Canada. Heart defects were identified via data from the Maintenance and Use of Data for the Study of Hospital Clientele registry. The main exposures were average concentration of PM2.5 and NO2 in a) the first trimester and b) the month of conception. Exposures were estimated at the residential postal code. Associations with critical and noncritical heart defects were assessed using logistic regression models, adjusted for maternal and infant characteristics. We considered single- and two-pollutant models and assessed modifying effects of maternal comorbidity, including preexisting hypertension, preeclampsia, anemia, and diabetes.

RESULTS

The cohort comprised 1,342,198 newborns, including 12,715 with heart defects. Exposure in the first trimester and month of conception yielded similar results; both were associated with a greater risk of heart defects. Adjusted odds ratios (OR) for any heart defect per interquartile range increase were 1.02 (95% CI: 1.00, 1.05) for PM2.5 and 1.10 (95% CI: 1.07, 1.13) for NO2. Associations with atrial septal defects were 1.08 (95% CI: 1.03, 1.14) for PM2.5 and 1.19 (95% CI: 1.12, 1.25) for NO2. Corresponding ORs for ventricular septal defects and individual critical heart defects were not significant. PM2.5 (OR=1.11; 95% CI: 1.06, 1.17) and NO2 (OR=1.23; 95% CI: 1.17, 1.31) exposure were associated with a greater risk of heart defects in mothers with comorbidity.

DISCUSSION

In this population-based cohort, prenatal exposure to ambient air pollution during the first trimester was associated with an increased risk of heart defects, particularly atrial septal defects. The association with heart defects was greater in mothers with comorbidity. https://doi.org/10.1289/EHP11120.

Benefits and Risks of Bariatric Surgery on Women's Reproductive Health: a Narrative Review

Bariatric surgery (BS) is escalating as the most efficient and endurable therapy for severe obesity. Women's reproductive health is essential to women's quality of life and is receiving increasing attention. However, despite the high prevalence of BS among women, the effect of BS on reproductive health remains underemphasis. The purpose of this narrative review is to provide an overview of BS on women's reproductive health, including their reproductive health before, during, and after pregnancy. Although limited attention has been given, current evidence highlights the substantial implications of bariatric surgery on reproductive health and reminds us of the importance of adopting decision-making conversations about reproductive health before bariatric surgery.

Folic Acid, Folinic Acid, 5 Methyl TetraHydroFolate Supplementation for Mutations That Affect Epigenesis through the Folate and One-Carbon Cycles

Methylation is an essential biochemical mechanism that is central to the transmission of life, and crucially responsible for regulating gametogenesis and continued embryo development. The methylation of DNA and histones drives cell division and regulation of gene expression through epigenesis and imprinting. Brain development and its maturation also depend on correct lipid methylation, and continued neuronal function depends on biogenic amines that require methylation for their synthesis. All methylation processes are carried out via a methyltransferase enzyme and its unique co-factor S-adenosylmethionine (SAM); the transfer of a methyl group to a target molecule results in the release of SAH (SA homocysteine), and then homocysteine (Hcy). Both of these molecules are toxic, inhibiting methylation in a variety of ways, and Hcy recycling to methionine is imperative; this is achieved via the one carbon cycle, supported by the folates cycle. Folate deficiency causes hyperhomocysteinaemia, with several associated diseases; during early pregnancy, deficiency interferes with closure of the neural tube at the fourth week of gestation, and nutraceutical supplementation has been routinely prescribed to prevent neural tube defects, mainly involving B vitamins, Zn and folates. The two metabolic pathways are subject to single nucleotide polymorphisms that alter their activity/capacity, often severely, impairing specific physiological functions including fertility, brain and cardiac function. The impact of three types of nutraceutical supplements, folic acid (FA), folinic acid (FLA) and 5 Methyl THF (MTHF), will be discussed here, with their positive effects alongside potentially hazardous secondary effects. The issue surrounding FA and its association with UMFA (unmetabolized folic acid) syndrome is now a matter of concern, as UMFA is currently found in the umbilical cord of the fetus, and even in infants’ blood. We will discuss its putative role in influencing the acquisition of epigenetic marks in the germline, acquired during embryogenesis, as well as the role of FA in the management of cancerous disease.

Maternal mental disorders and risk of pathological abdominal conditions in children

The etiology of pediatric abdominal disorders is poorly understood, and the relationship with maternal mental health is understudied. We sought to determine the association between maternal psychiatric disorders and abdominal conditions in childhood. We performed a retrospective cohort study of 1,080,518 newborns in Quebec, Canada, between 2006 and 2020. We identified maternal mental disorders before or during pregnancy and computed the incidence of abdominal disorders in offspring before 1 year of age. Outcomes included Hirschsprung disease; hypertrophic pyloric stenosis; and esophageal, intestinal, and biliary atresia. We calculated adjusted risk ratios (RR) with 95% confidence intervals (CI) for the association of maternal mental disorders with these pediatric abdominal disorders. Among 51,371 children exposed to maternal mental disorders, 200 children had an abdominal condition, for a rate of 38.9 cases per 10,000 children (95% CI 33.6-44.3) compared with 27.7 per 10,000 for children who were unexposed to maternal mental disorders (95% CI 26.7-28.7). Compared with no mental disorder, maternal mental disorders were associated with hypertrophic pyloric stenosis (RR 1.39, 95% CI 1.16-1.68). Associations were stronger for severe mental disorders and were more marked for depression and stress and anxiety disorders. Maternal mental disorders are associated with the risk of hypertrophic pyloric stenosis in offspring. The origin of hypertrophic pyloric stenosis may relate to maternal mental disorders that were present during pregnancy.

The effects of bariatric surgery on periconception maternal health: a systematic review and meta-analysis

BACKGROUND

Worldwide, the prevalence of obesity in women of reproductive age is increasing. Bariatric surgery is currently viewed as the most effective, long-term solution for this problem. Preconception bariatric surgery can reduce the prevalence of obesity-related subfertility and adverse maternal, pregnancy and birth outcomes. Maternal health during the periconception period is crucial for optimal gametogenesis and for embryonic and fetal development which also affects health in the later lives of both mother and offspring. Although preconception bariatric surgery improves several pregnancy outcomes, it can also increase the prevalence of pregnancy complications due to excessive and rapid weight loss. This can lead to iatrogenic malnutrition with vitamin deficiencies and derangements in metabolic and endocrine homeostasis. Thus, bariatric surgery can greatly influence periconception maternal health with consequences for reproduction, pregnancy and health in later life. However, its influence on periconception maternal health itself has never been reviewed systematically.

OBJECTIVE AND RATIONALE

The aim of this review was to investigate associations between bariatric surgery and determinants of periconception maternal health such as endocrine changes, fertility, vitamin status, irregular menstrual cycles, miscarriages and congenital malformations.

SEARCH METHODS

Medline, Embase, PubMed, Web of Science, Google Scholar and the Cochrane databases were used for the literature search until 1 November 2020. The search strategy terms included, among others, bariatric surgery, hormones, fertility, malformations, miscarriages and vitamin status. We searched for human studies that were written in English. Abstracts, reviews, meta-analyses and conference papers were excluded. The ErasmusAGE score was used to assess the quality of the included studies.

OUTCOMES

A total of 51 articles were analysed. The mean quality score was 5 (range 2-8). After bariatric surgery, hormonal axes normalized and menstrual cycle regularity was restored, resulting in increased fertility. Overall, there were no short-term risks for reproductive outcomes such as the increased risk of miscarriages or congenital malformations. However, the risk of vitamin deficiencies was generally increased after bariatric surgery. A meta-analysis of 20 studies showed a significant decrease in infertility (risk difference (RD) -0.24, 95% confidence interval (CI) -0.42, -0.05) and menstrual cycle irregularities (RD -0.24, 95% CI -0.34, -0.15) with no difference in rates of miscarriage (RD 0.00, 95% CI -0.09, 0.10) and congenital malformations (RD 0.01, 95% CI -0.02, 0.03).

WIDER IMPLICATIONS

The current systematic review and meta-analysis show associations between bariatric surgery and periconception maternal health and underlines the need for providing and personalizing preconception care for women after bariatric surgery. We recommend preconception care including the recommendation of postponing pregnancy until weight loss has stabilized, irrespective of the surgery-to-pregnancy interval, and until vitamin status is normalized. Therefore, regular monitoring of vitamin status and vitamin supplementation to restore deficiencies is recommended. Furthermore, this systematic review emphasizes the need for a long-term follow-up research of these women from the periconception period onwards as well as their pregnancies and offspring, to further improve care and outcomes of these mothers and children.

Original article: is the protective association between hyperemesis gravidarum and birth defects biased by pregnancy termination?

PURPOSE

We assessed whether the protective association between hyperemesis gravidarum and birth defects could be due to selection bias from exclusion of pregnancy terminations.

METHODS

We designed a cohort study of 2,115,581 live births in Canada, 1990-2016. The main exposure measure was hyperemesis gravidarum. The main outcome measure included any birth defect at delivery. We estimated risk ratios (RR) and 95% confidence intervals (CI) for the association of hyperemesis gravidarum with birth defects in log-binomial regression models, and assessed the extent of selection bias through correction factors.

RESULTS

Hyperemesis gravidarum was associated with 0.88 times the risk of birth defects in models not corrected for bias (95% CI 0.82-0.94). Correction for selection bias suggested that if screening for birth defects was associated with 1.33 times the chance of detecting birth defects and having a pregnancy termination, there would be no association with hyperemesis gravidarum. If ultrasound was associated with 2.00 times the chance of detecting birth defects and 1.50 times the risk of pregnancy termination, hyperemesis gravidarum would be associated with 1.27 times the risk of birth defects (95% CI 1.18-1.35).

CONCLUSIONS

The protective association between hyperemesis gravidarum and birth defects in previous studies may be due to selection bias.

Embryopathy Following Maternal Biliopancreatic Diversion: Is Bariatric Surgery Really Safe?

Pregnancy after bariatric surgery is usually considered safe. Recently, a few studies reported that bariatric surgery represents a risk factor for birth defects. A case series of six patients, born from women who had undergone biliopancreatic diversion, is reported. The clinical pattern was characterized by psychomotor development delay (100%), microphthalmia (83%), growth retardation (66%), hearing loss (66%), and variable facial dysmorphism. Based on the clinical profile and symptoms reported by women during pregnancy, a causal association between maternal chronic post-surgical malabsorption, congenital anomalies, and neonatal outcome is proposed, with vitamin A deficiency representing a major causing factor. Educational follow-up support, continuous clinical monitoring, and appropriate nutritional assessment appear to be crucial to reduce the potential risk of congenital malformations and child disability.

Inflammatory Bowel Disease and Risk of Birth Defects in Offspring

BACKGROUND AND AIMS

The relationship between inflammatory bowel disease in pregnancy and birth defects is not understood. We evaluated whether Crohn's disease and ulcerative colitis in pregnant women were associated with the risk of birth defects in the offspring.

METHODS

We undertook a retrospective cohort study of 2 184 888 pregnancies in Quebec, Canada, between 1989 and 2016. We calculated risk ratios [RR] and 95% confidence intervals [CI] for the association between inflammatory bowel disease and the risk of birth defects, using generalised estimating equations adjusted for maternal characteristics. We assessed associations in the period before 2000, when immunosuppressive biologic therapy and folic acid food fortification were not yet available, compared with the period after 2000 when these interventions were more widespread.

RESULTS

This study included 13 099 women with Crohn's disease and 7798 with ulcerative colitis. Crohn's disease was associated with 1.90 times [95% CI 1.10-3.28] the risk of abdominal wall defects [gastroschisis, omphalocoele, and diaphragmatic hernia] and ulcerative colitis was associated with 1.53 times [95% CI 1.02-2.30] the risk of central nervous system defects. The association of Crohn's disease with abdominal wall defects was stronger before 2000 [RR 3.62, 95% CI 1.71-7.67] than after 2000 [RR 1.23, 95% CI 0.55-2.75]. Ulcerative colitis was associated with central nervous system defects regardless of time period.

CONCLUSIONS

These findings suggest that inflammatory bowel disease is associated with the risk of abdominal wall and central nervous system defects, and that introduction of immunobiologic medications is unlikely to be associated with added risk.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.