Initiation and duration of folic acid supplementation in preventing congenital malformations.

BACKGROUND: Folic acid (FA) supplementation is associated with a lower risk of the neural tube and heart defects and is recommended for women of childbearing age. Although there are detailed recommendations, differences in the initiation time and duration of FA supplementation remain poorly studied. METHODS: A multicentre prospective study of 17,713 women was conducted. The incidence of congenital malformations in women taking a recommended dosage (e.g. 0.4 or 0.8 mg/day) of FA was compared with that in women without supplementation. The predicted probability of malformations by the initiation time and duration of FA use was estimated to determine optimal options. RESULTS: Periconceptional FA supplementation was associated with a lower and insignificant risk of congenital malformations (1.59% vs. 2.37%; odds ratio [OR] 0.69; 95% confidence interval [CI]: 0.44-1.08), heart defects (3.8 vs. 8.0 per 1000 infants; OR, 0.47; 0.21-1.02), and neural tube defects (7.0 vs. 11.5 per 10,000 infants; OR, 0.64; 0.08-5.15). FA use after pregnancy provided greater protection against total malformations. Statistically significant associations were found in women who initiated FA supplementation in the first month of gestation (OR, 0.55; 95% CI: 0.33-0.91) and in those who supplemented for 1 to 2 months (OR, 0.59; 95% CI: 0.36-0.98). Similar results were found for heart defects. The optimal initiation time was 1.5 (optimal range: 1.1 to 1.9) months before pregnancy and a duration of 4.0 (3.7 to 4.4) months was reasonable to achieve the lowest risk of congenital malformations. Heart defect prevention required an earlier initiation (2.2 vs. 1.1 months before pregnancy) and a longer duration (4.7 vs. 3.7 months) than the prevention of other malformations. CONCLUSIONS: The timely initiation of FA supplementation for gestation was associated with a decreased risk of congenital malformations, which was mainly attributed to its protection against heart defects. The initiation of FA supplementation 1.5 months before conception with a duration of 4 months is the preferred option for congenital malformation prevention. TRIAL REGISTRATION: Chictr.org.cn identifier: ChiCTR-SOC-17010976.

Maternal traditional Chinese medicine exposure and risk of congenital malformations: a multicenter prospective cohort study.

INTRODUCTION: The potential teratogenic risk of traditional Chinese medicine (TCM) is of widespread concern; however, related evidence is largely absent in humans. This study aimed to compare the prevalence of congenital malformations between pregnant women with and without TCM exposure. MATERIAL AND METHODS: This was a multicenter prospective cohort study of 17 713 women who participated in a survey on periconceptional TCM exposure. Primary outcome was congenital malformations diagnosed from a survey conducted on the day 42 after delivery. RESULTS: A total of 16 751 pregnant women with 273 congenital malformations were included in the analysis. Fetuses exposed to TCM had an increased risk of congenital malformations compared to those without exposure (odds ratio [OR] 2.10; 95% confidence interval [CI] 1.09-4.02) after controlling for potential confounders. There were significant associations with congenital malformations in women with early pregnant exposure (OR 2.04, 95% CI 1.00-4.20) and for those who received ≥2 TCM formulas (OR 5.84, 95% CI 1.44-23.65). Pre-pregnancy TCM exposure was significantly associated with an increased risk of congenital heart defects (OR 12.69; 95% CI 3.01-53.51). CONCLUSIONS: Periconceptional TCM exposure is associated with an increased risk of congenital malformation. This effect was cumulative and sensitive to periconceptional age. Therefore, TCM deserves more attention and should be used cautiously for pregnant women and those trying to become pregnant.