The role of Vitamin B12 and genetic risk factors in the etiology of neural tube defects: A systematic review

Surgical outcomes of myelomeningocele repair: A 20-year experience from a single center in a middle-income country

BACKGROUND AND PURPOSE

Spina bifida is the second major cause of congenital disorders and the most common central nervous system congenital malformation compatible with life primarily. Herein, we describe the short-term outcome of post-natal Myelomeningocele (MMC) surgical management and predictors of its postoperative complications and mortality.

METHODS

This retrospective chart review studies the children who underwent post-natal surgical management for MMC in Namazi hospital, a tertiary referral center, in southern Iran from May 2001 to September 2020.

RESULTS

248 patients were included in this study. The mean age at the operation was 8.47 ± 8.69 days. The most common site of involvement of MMC was Lumbosacral (86%, n = 204). At the evaluation conducted prior to the operation, cerebrospinal fluid leak was observed in 7% (n=16) of the patients. Postoperatively, 5.7% of the patients expired in the 30-day follow-up after the operation (n = 14), while 24% needed readmission (n = 47). The most common complications leading to readmission were wound dehiscence (n = 10, 42%) and wound purulence (n = 6, 25%). Only the site of the lesion (p-value = 0.035) was associated with postoperative complication. After controlling for potential confounders, the site of the lesion (adjusted odds ratio = 0.146, 95% confidence interval = 0.035-0.610, p-value = 0.008) and age at surgery (adjusted odds ratio = 1.048, 95% confidence interval = 1.002-1.096, p-value = 0.041) were significantly associated with mortality CONCLUSIONS: The age of the patients at the surgery and the site of the lesion are the two factors that were associated with mortality. However, further investigations into preoperative interventions and risk factors to mitigate the risk of complications and mortality are highly encouraged.

Vitamin B12 supplementation during pregnancy for maternal and child health outcomes

BACKGROUND

Vitamin B12 deficiency is a major public health problem worldwide, with the highest burden in elderly people, pregnant women, and young children. Due to its role in DNA synthesis and methylation, folate metabolism, and erythropoiesis, vitamin B12 supplementation during pregnancy may confer longer-term benefits to maternal and child health outcomes.

OBJECTIVES

To evaluate the benefits and harms of oral vitamin B12 supplementation during pregnancy on maternal and child health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP) on 2 June 2023, and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs, or cluster-RCTs evaluating the effects of oral vitamin B12 supplementation compared to placebo or no vitamin B12 supplementation during pregnancy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Four review authors independently assessed trial eligibility. Two review authors independently extracted data from included studies and conducted checks for accuracy. Three review authors independently assessed the risk of bias of the included studies using the Cochrane RoB 1 tool. We used GRADE to evaluate the certainty of evidence for primary outcomes.

MAIN RESULTS

The review included five trials with 984 pregnant women. All trials were conducted in low- and middle-income countries, including India, Bangladesh, South Africa, and Croatia. At enrolment, 26% to 51% of pregnant women had vitamin B12 deficiency (less than 150 pmol/L), and the prevalence of anaemia (haemoglobin less than 11.0 g/dL) ranged from 30% to 46%. The dosage of vitamin B12 supplementation varied from 5 μg/day to 250 μg/day, with administration beginning at 8 to 28 weeks' gestation through to delivery or three months' postpartum, and the duration of supplementation ranged from 8 to 16 weeks to 32 to 38 weeks. Three trials, involving 609 pregnant women, contributed data for meta-analyses of the effects of vitamin B12 supplementation compared to placebo or no vitamin B12 supplementation. Maternal anaemia: there may be little to no difference for maternal anaemia by intervention group, but the evidence is very uncertain (70.9% versus 65.0%; risk ratio (RR) 1.08, 95% confidence interval (CI) 0.93 to 1.26; 2 trials, 284 women; very low-certainty evidence). Maternal vitamin B12 status: vitamin B12 supplementation during pregnancy may reduce the risk of maternal vitamin B12 deficiency compared to placebo or no vitamin B12 supplementation, but the evidence is very uncertain (25.9% versus 67.9%; RR 0.38, 95% CI 0.28 to 0.51; 2 trials, 272 women; very low-certainty evidence). Women who received vitamin B12 supplements during pregnancy may have higher total vitamin B12 concentrations compared to placebo or no vitamin B12 supplementation (mean difference (MD) 60.89 pmol/L, 95% CI 40.86 to 80.92; 3 trials, 412 women). However, there was substantial heterogeneity (I2 = 85%). Adverse pregnancy outcomes: the evidence is uncertain about the effect on adverse pregnancy outcomes, including preterm birth (RR 0.97, 95% CI 0.55 to 1.74; 2 trials, 340 women; low-certainty evidence), and low birthweight (RR 1.50, 95% CI 0.93 to 2.43; 2 trials, 344 women; low-certainty evidence). Two trials reported data on spontaneous abortion (or miscarriage); however, the trials did not report quantitative data for meta-analysis and there was no clear definition of spontaneous abortion in the study reports. No trials evaluated the effects of vitamin B12 supplementation during pregnancy on neural tube defects. Infant vitamin B12 status: children born to women who received vitamin B12 supplementation had higher total vitamin B12 concentrations compared to placebo or no vitamin B12 supplementation (MD 71.89 pmol/L, 95% CI 20.23 to 123.54; 2 trials, 144 children). Child cognitive outcomes: three ancillary analyses of one trial reported child cognitive outcomes; however, data were not reported in a format that could be included in quantitative meta-analyses. In one study, maternal vitamin B12 supplementation did not improve neurodevelopment status (e.g. cognitive, language (receptive and expressive), motor (fine and gross), social-emotional, or adaptive (conceptual, social, practical) domains) in children compared to placebo (9 months, Bayley Scales of Infant and Toddler Development Third Edition (BSID-III); 1 trial; low-certainty evidence) or neurophysiological outcomes (72 months, event-related potential measures; 1 trial; low-certainty evidence), though children born to women who received vitamin B12 supplementation had improved expressive language domain compared to placebo (30 months, BSID-III; 1 trial; low-certainty evidence).

AUTHORS' CONCLUSIONS

Oral vitamin B12 supplementation during pregnancy may reduce the risk of maternal vitamin B12 deficiency and may improve maternal vitamin B12 concentrations during pregnancy or postpartum compared to placebo or no vitamin B12 supplementation, but the evidence is very uncertain. The effects of vitamin B12 supplementation on other primary outcomes assessed in this review were not reported, or were not reported in a format for inclusion in quantitative analyses. Vitamin B12 supplementation during pregnancy may improve maternal and infant vitamin B12 status, but the potential impact on longer-term clinical and functional maternal and child health outcomes has not yet been established.

Determinants of neural tube defects among women who gave birth in hospitals in Eastern Ethiopia: evidence from a matched case control study

INTRODUCTION

Neural tube defects (NTDs) are severe birth defects caused by nutritional, genetic or environmental factors. Because NTDs continue to have a significant health and economic impact on children and community at large, it is crucial to investigate potential risk factors in order to develop novel approaches to NTDs prevention. Determinants for the development of NTDs differ by country, region as well as within the country. The objective of this study was to identify the determinants of NTDs among newborns delivered in three hospitals found in eastern Ethiopia.

METHODS

A hospital-based matched case-control study was conducted among 138 cases and 138 control women who delivered in three teaching hospitals in Eastern Ethiopia in 2021. Data were collected using a structured and pre-tested interviewer-administered questionnaire. Cases were mothers who delivered a neonate with any type of NTDs regardless of gestational age or fetal viability, whereas controls were mothers who delivered an apparently healthy newborn. Chi-square was used to assess the significant difference between the two groups. Conditional logistic regression model was used to generate adjusted odds ratio with its corresponding 95% confidence intervals and compare the two groups.

RESULTS

Anencephaly (51.4%) and spinal bifida (34.1%) were the most frequently observed NTDs. None of study participants took preconception folic acid supplementation. Being a non-formal mothers (AOR = 0.34, 95% CI: 0.12-0.92, P = 0.034), rural residence, (AOR = 3.4, 95% CI: 1.18-9.78, P = 0.023), history of spontaneous abortion (AOR = 2.95, 95% CI: 1.15-7.55, P = 0.023), having severe anemia (AOR = 3.4, 95% CI: 1.17-9.87, P = 0.024), history of fever or cold (AOR = 2.75; 95% CI: 1.05-7.15, P = 0.038), and an exposure to various agro-chemicals (AOR = 3.39, 95% CI: 1.11-10.3, P = 0.032) were independent determinants of NTDs.

CONCLUSION AND RECOMMENDATION

In this study, NTDs were associated to several determinant factors in the area, including residential area, history of spontaneous abortion, severe anemia, fever/cold, antibiotic use before or during early pregnancy, and exposure to agrochemicals. Addressing the identified determinants is critical in averting the incidence of NTDs in the study area. Moreover, more research is needed to investigate women's dietary practices as well as the practice of preconception folic acid supplementation for pregnant women in Ethiopia's current health care system.

Vitamins and minerals, education, and self-care need during preconception to 1000 days of life in Southeast Asia: An expert panel opinion

Addressing maternal malnutrition and its drivers is paramount in Southeast Asia. This article summarizes the key clinical learnings and evidence-based opinions from the experts to understand the need for vitamins and minerals supplementation, education, and self-care from preconception to the first 1000 days of life, which warranted further attention since COVID-19 pandemic. Evidence describing the importance of vitamins and minerals during preconception, pregnancy, and lactation stages was identified using literature databases. A pre-meeting survey was conducted to determine the current practices and challenges in Southeast Asia. Based on the literature review and clinical experience, experts defined the topics, and an online meeting was held on 13th July 2021. During the meeting, nine experts from Southeast Asia provided evidence-based opinion on the vitamins and minerals supplementation, education, and self-care need during preconception, pregnancy, and lactation stages. The expert opinions underpin maternal malnutrition as a prevalent issue and discuss appropriate interventions and prevention strategies for women in Southeast Asia. The recent pandemic further impacted nutrition status, pregnancy, and neonatal health outcomes. The expert panel emphasized a need to improve existing inadequacies in education, self-care, and social support, and discussed the role of policymakers in addressing the barriers to dietary changes. As inadequacies in regular vitamins and minerals supplementation, education, and self-care for women of reproductive age implicate maternal and child health outcomes, there is an urgent need for addressing malnutrition concerns in this population. Thus, a strong partnership between policymakers, healthcare professionals, and other relevant sectors is required.

Homocysteine Metabolism in Pregnancy and Developmental Impacts

Homocysteine is a metabolite generated by methionine cycle metabolism, comprising the demethylated derivative of methionine. Homocysteine can be metabolised by the transsulphuration pathway to cystathionine, which requires vitamin B6, or can undergo remethylation to methionine. Homocysteine remethylation to methionine is catalysed by methionine synthase activity which requires vitamin B12, regenerating methionine to allow synthesis of the universal methyl donor S-adenosylmethionine required for methylation and gene transcription regulation. The methyl-group donated for homocysteine remethylation comes from 5-methyltetrahydrofolate generated by the folate cycle, which allows tetrahydrofolate to be returned to the active folate pool for nucleotide biosynthesis. Therefore the integrated actions of the methionine and folate cycles, required to metabolise homocysteine, also perpetuate methylation and nucleotide synthesis, vitally important to support embryonic growth, proliferation and development. Dysregulated activities of these two interdependent metabolic cycles, arising from maternal suboptimal intake of nutrient co-factors such as folate and vitamin B12 or gene polymorphisms resulting in reduced enzymatic activity, leads to inefficient homocysteine metabolic conversion causing elevated concentrations, known as hyperhomocysteinemia. This condition is associated with multiple adverse pregnancy outcomes including neural tube defects (NTDs). Raised homocysteine is damaging to cellular function, binding to proteins thereby impairing their function, with perturbed homocysteine metabolism impacting negatively on embryonic development. This review discusses the "cross-talk" of maternal-fetal homocysteine interrelationships, describes the placental transport of homocysteine, homocysteine impacts on pregnancy outcomes, homocysteine and methylation effects linking to NTD risk and proposes a putative pathway for embryonic provision of folate and vitamin B12, homocysteine-modulating nutrients that ameliorate NTD risk.

Genetic Variants in Folate and Cobalamin Metabolism-Related Genes in Pregnant Women of a Homogeneous Spanish Population: The Need for Revisiting the Current Vitamin Supplementation Strategies

Polymorphisms of genes involved in the metabolism and transport of folate and cobalamin could play relevant roles in pregnancy outcomes. This study assessed the prevalence of genetic polymorphisms of folate and cobalamin metabolism-related genes such as MTHFR, MTR, CUBN, and SLC19A1 in pregnant women of a homogeneous Spanish population according to conception, pregnancy, delivery, and newborns complications. This study was conducted on 149 nulliparous women with singleton pregnancies. Sociodemographic and obstetrics variables were recorded, and all patients were genotyped in the MTHFR, MTR, CUBN, and SLC10A1 polymorphisms. The distribution of genotypes detected in this cohort was similar to the population distribution reported in Europe, highlighting that more than 50% of women were carriers of risk alleles of the studied genes. In women with the MTHFR risk allele, there was a statistically significant higher frequency of assisted fertilisation and a higher frequency of preeclampsia and preterm birth. Moreover, CUBN (rs1801222) polymorphism carriers showed a statistically significantly lower frequency of complications during delivery. In conclusion, the prevalence of genetic variants related to folic acid and vitamin B12 metabolic genes in pregnant women is related to mother and neonatal outcomes. Knowing the prevalence of these polymorphisms may lead to a personalised prescription of vitamin intake.