The association between periconceptional folic acid supplementation and the risk of preterm birth: a population-based retrospective cohort study of 200,000 women in China

Abstract

Purpose The aim of this study was to examine the association between periconceptional folic acid (FA) supplementation and risk of preterm birth. Methods We conducted a retrospective cohort study in women aged 18–49 who participated in the NFPHEP from 2010 to 2018, and had a singleton livebirth in 129 counties in southwest China. Participants were divided into four groups according to the time period starting FA use: no use, after the last menstrual period, at least 1–2 months before the last menstrual period, at least 3 months before the last menstrual period. The outcomes were preterm birth (gestation < 37 weeks) and early preterm birth (gestation < 34 weeks). Results 201,477 women were included and 191,809 (95.2%) had taken FA during periconception. Compared with women who did not take FA, women who started taking FA 1–2 months before their last menstrual period had a 15% lower risk of preterm birth (aOR = 0.85, 95% CI 0.79–0.92), and women who started taking FA at least 3 months before their last menstrual period had a 20% lower risk of preterm birth (aOR = 0.80, 95% CI 0.75–0.87), but women who started taking FA after their last menstrual period did not appear to reduce the risk of preterm birth. Conclusions In this study of 200,000 Chinese women, periconceptional supplementation with FA was associated with a lower risk of preterm birth. Women who started taking FA at least 3 months before their last menstrual period were more likely to reduce the risk of preterm birth.

Association between season of conception, month of conception with preterm birth in China: a population-based retrospective cohort study

“…First, this study was a large population-based retrospective cohort study that recruited all women who participated in the NFPHEP and had a singleton livebirth from 129 counties of Southwest China between 2010 and 2018, which may have less selection bias. Second, our study adjusted the demographic characteristics, reproductive characteristics, health status and living habits during pregnancy which were related to preterm birth in stages, especially the HBsAg positive [ 4 ] and folic acid supplementation [ 43 ] found in the previous study that may increase or reduce the risk of preterm birth, and the results of the association between conception season and preterm birth were more reliable. In addition, this was the first study to explore the association between season of conception, month of conception and preterm birth in Southwest China.…”

Nationwide-free preconception care strategy: Experience from China

“…Second, folic acid supplementation is widely recommended for couples with pregnancy intention to reduce the risk of neural tube defects in their offspring ( 55 ). In a cohort who took part in the preconception care program, preconception folic supplementation reduced the risk of spontaneous abortion and preterm birth ( 56 , 57 ). Moreover, an earlier start of taking folic acid supplements is important.…”

Periconceptional folic acid usage and its associated factors in eastern Sudan: A cross-sectional study

“…Maternal folate deficiency in the periconceptional and early pregnancy period may lead to adverse maternal and perinatal outcomes, including neural tube defects (NTDs). 1 – 3 The World Health Organization (WHO) recommended pregnant women taking 0.4 mg/day of folic acid in the periconceptional period. 1 However, higher doses (4–5 mg/day) are recommended for higher-risk groups such as those with periconceptional antiepileptic drug exposure, pre-gestational diabetes, pre-pregnancy obesity, or family history of NTDs.…”

“…1 However, higher doses (4–5 mg/day) are recommended for higher-risk groups such as those with periconceptional antiepileptic drug exposure, pre-gestational diabetes, pre-pregnancy obesity, or family history of NTDs. 4 , 5 The act of taking folic acid before conception and continuing until 12 weeks of gestation (periconceptional period) is associated with a lowered risk of NTDs, 6 congenital heart defects, 7 spontaneous abortion, stillbirth, 3 preterm birth, 2 , 8 and anemia. 8 In spite of this WHO recommendation and its documented benefits, the use of folic acid supplementation in the periconceptional period is still low in several countries, especially in countries with limited-resource settings.…”