Neural Tube Defects In Relation Research Articles

Prevention of Fetal Neural Tube Defect with Folic Acid Supplementation

Prevention of Fetal Neural Tube Defect with Folic Acid Supplementation

Clomiphene citrate and neural tube defects: a meta-analysis of controlled observational studies.

At the end of the 1980s, several studies suggested a potential increased risk of neural tube defects (NTDs) with ovulation induction/fertility drugs, especially with clomiphene citrate (CC). A previous meta-analysis of observational studies evaluating the risk of NTDs associated with the use of CC performed in 1995 found a risk ratio of 1.08 (95%CI 0.76-1.51). Since then, additional studies have been published and the risk of NTDs associated with periconceptional CC exposure may have changed. To perform an updated quantitative meta-analysis of the risk of NTDs associated with periconceptional CC exposure. MEDLINE, Web of Science, and Scopus were searched (October 2018). Comparative cohort and case-control studies investigating the risk of NTDs after periconceptional CC exposure. Pooled effect sizes with corresponding 95%CIs were calculated using random effects models, comparing the risk of NTDs between pregnancies exposed and not exposed to CC. Thirteen studies met the inclusion criteria, totalling 218819 pregnancies. Periconceptional exposure to CC was not significantly associated with an increased risk of NTDs (pooled odds ratio 1.21, 95%CI 0.88-1.66). No heterogeneity between studies was observed (I2 =26%). A funnel plot and asymmetry test were not suggestive of publication bias. Our meta-analysis confirms that exposure to CC before or in early pregnancy was associated with a 21% increased risk of NTD in relation to CC exposure; however, this increased risk is not statistically significant. A new meta-analysis finds that clomiphene citrate exposure before or in early pregnancy is not associated with an increased risk of NTDs.

Low maternal vitamin B12 is a risk factor for neural tube defects: a meta-analysis

Objective. The objective of this study was to assess whether low level of maternal vitamin B12 is associated with an increased risk of fetal neural tube defects (NTDs), in order to contribute to research on further reduction of NTDs under a background of mandatory folic acid (FA) fortification.Methods. A meta-analysis was conducted. We retrieved and evaluated the studies published on the risk of low level of maternal vitamin B12 for NTDs. The homogeneity of the studies was examined using the forest graph. Meta-analysis was applied to calculate the odds ratio (OR) of fetal NTDs in relation to low maternal B12 and its 95% confidence interval (CI).Results. We identified nine published articles including 567cases and 1566 controls in the meta-analysis. All the studies selected were homogeneous according to the forest graph (χ2 = 15.05, P < 0.1). The estimated OR value of fetal NTDs in relation to low maternal B12 was 2.41 (95% CI: 1.90–3.06).Conclusion. Low maternal B12 status could be an important risk factor for the development of fetal NTDs. The addition of synthetic B12 to current recommendations for periconceptional FA tablet supplements or FA-fortified foods should be considered.

International Retrospective Cohort Study of Neural Tube Defects in Relation to Folic Acid Recommendations: Are the Recommendations Working?

This retrospective cohort study was planned to determine whether recommendations to take folic acid have in fact lessened the risk of neural tube defects. Recommendations typically include eating a healthy diet and takingfolic acid supplements when planning pregnancy or throughout the childbearing years. In a few countries, including the United States, flour is fortified so that much of the population will receive at least a small supplemental amount of folic acid. Many governments promote the use of supplements because folic acid is inexpensive, safe, and easy to use. The authors acquired information on more than 13 million births from 13 birth defects registries in Norway that monitored rates of neural tube defects from 1988 to 1998. Cases of anencephaly and spina bifida totaled 8636. Rates of defects were stable during the 10-year monitoring interval in most areas. There were no evident changes in rates of defects after local recommendations were issued. Comparable findings were obtained when analyzing anencephaly and spina bifida separately and combined. Folic acid use in Europe is, in general, low; in Norway, it is approximately 10%. In China, intensive educational efforts and a high rate of planned pregnancies probably are responsible for the effectiveness of a public health campaign to promote the use of folic acid supplements. Rates of folic acid use generally follow economic and educational trends. Fortifying flour with folic acid holds promise for delivering some folic acid to a large part of the population, crossing social and economic barriers. Blood folate levels have increased rapidly where this practice is followed. It is estimated that thousands of neural tube defects occurring since 1992 could have been prevented.

International retrospective cohort study of neural tube defects in relation to folic acid recommendations: are the recommendations working?

Objectives To evaluate the effectiveness of policies and recommendations on folic acid aimed at reducing the occurrence of neural tube defects.Design Retrospective cohort study of births monitored by birth defect...

Vitamin B12 insufficiency and the risk of fetal neural tube defects.

Although maternal folate insufficiency is a risk factor for fetal neural tube defects (NTDs), there is controversy about whether vitamin B12 (B12) insufficiency is also associated with an increased risk of NTDs. To investigate whether low maternal B12 is associated with an increased risk of fetal NTDs. Systematic review. A systematic search of Medline between 1980 and October 2002, with an examination of the citations of all retrieved studies. Studies were included that: (i) used a cohort or case-control design; (ii) included case mothers with a prior or current NTD-affected pregnancy; (iii) assessed a group of unaffected 'controls'; and (iv) measured the vitamin B12 status of all participants. Overall, 17 case-control studies were included, mean sample size 33 cases and 93 controls. In 5/6, mean amniotic fluid B12 concentration was significantly lower in case mothers than in controls. Of 11 that measured maternal serum or plasma B12, three observed a significantly lower mean concentration in case mothers vs. controls, while five others found a non-significant lower trend in the case group. One study observed a significantly higher mean concentration of maternal serum methylmalonic acid among the maternal cases, while another found a non-significant lower mean concentration of plasma holo-transcobalamin. Five studies estimated the risk of NTDs in relation to low B12 or B12-related metabolic markers: it was significantly increased in three studies, with a non-significant trend in the fourth. There seems to be a moderate association between low maternal B12 status and the risk of fetal NTDs. However, several design limitations, and the inclusion of few study participants, may have under-represented this. A large observational study, using reliable and valid indicators of B12 status in early pregnancy, could best assess the association between B12 insufficiency and the risk of fetal NTDs.

Neural tube defects in relation to use of folic acid antagonists during pregnancy.

Periconceptional folic acid supplementation reduces the risk of neural tube defects (NTDs). To determine whether periconceptional exposure to folic acid antagonists (FAAs) might therefore increase the risk of NTDs, the authors examined data from an ongoing case-control study of birth defects (1979-1998) in the United States and Canada. They compared data on 1,242 infants with NTDs (spina bifida, anencephaly, and encephalocele) with data from a control group of 6,660 infants with malformations not related to vitamin supplementation. Mothers were interviewed within 6 months of delivery about demographic, reproductive, medical, and behavioral factors and about medication use. The adjusted odds ratios of NTDs related to exposure to FAAs (including carbamazepine, phenobarbital, phenytoin, primidone, sulfasalazine, triamterene, and trimethoprim) during the first or second months after the last menstrual period, compared with no use in either month, were 2.8 (95% confidence interval: 1.7, 4.6) for FAAs as a group, 4.8 (95% confidence interval: 1.5, 16.1) for trimethoprim (based on five exposed cases), and 6.9 (95% confidence interval: 1.9, 25.7) for carbamazepine (six exposed cases). These results are adjusted for region, interview year, periconceptional folic acid supplementation, maternal age, weight, education, and infections early in pregnancy. These findings suggest that a number of FAAs may increase NTD risk, and they provide estimates of risk for selected drugs.

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Neural Tube Defects in Relation to Use of Folic Acid Antagonists During Pregnancy

Risk of neural tube defects in relation to maternal fertility and fertility drug use

In a case-control study to investigate whether women who use drugs to induce ovulation are at increased risk of conception of a child with a neural tube defect, 571 women who had a fetus or child with a neural tube defect, 546 women who had a fetus or child with other abnormalities, and 573 women who had an apparently normal fetus or child were questioned about infertility, fertility drug use, and related obstetric problems. The rate of maternal fertility drug use around the time of conception was not significantly higher for neural tube defects than for other abnormalities (odds ratio 1.28; 95% confidence interval 0.39, 4.51) or no abnormalities (odds ratio 0.80; 95% Cl 0.27, 2.27). Fertility drug use at any time was not significantly more frequent for neural tube defects than for other abnormalities (odds ratio 1.37; 95% Cl 0.70, 2.74) or no abnormalities (odds ratio 1.05; 95% Cl 0.56, 1.98).