To evaluate the protective effect of 400ug folic acid supplementsn on fetal/infantile neural tube malformation (NTDs) in women before and after pregnancy.

  • General Information of Study
    • Overview
      Name Sino-US collaborative project on folic acid in prevention of neural tube defects
      Project Number CCC2017051601
      Website None
      LIU Jianmeng
      Institutions Peking University Institute of Reproductive and Child Health
      LI Zhiwen
      Funding U.S. Centers for Disease Control, 1993, Project funding No. 404
      Objectives To evaluate the protective effect of 400ug folic acid supplementsn on fetal/infantile neural tube malformation (NTDs) in women before and after pregnancy.
      Start Date 1993/10/1
      End Date 1996/12/31
    • Study Design
      Number of Participants A total of 247,831 women were recruited from regions with high prevalence of NTDs in northern China and regions with low prevalence of NTDs in the south, including 130,142 women who took medicine at any time before or after pregnancy, and 117,689 women who did not take medicine.
      Age Range 20-35 years old
      Geographic Distribution 21 counties and cities in Jiangsu, Zhejiang and Hebei provinces
      General Information of Study Design and Sample Methods On the basis of informed consent, all premarital women or women in the early period of pregnancy in the regions were included in the population-based study.
      Inclusion Criteria Subjects consisted of women married in October 1993 to September 1995 and recruited, and women getting pregnant and delivered at any time in the period from October 1, 1993 to December 31st, 1996. Birth out of all subjects were clear.
      Exclusion Criteria None
    • Other Information
      Key Achievements The results showed that for women whose compliance rate was above 80%, the prevention rate of NTDs was 85% in the north and 40% in the south. If women take folic acid 400ug daily before and after pregnancy, neonatal NTDs morbidity can be effectively prevented in both regions with high and low prevalence of NTDs, which provides a reference for developing or revising public health policy for a nation. In addition, folic acid supplement could also effectively prevent neonates’ cleft lip and palate, anal atresia and maternal spontaneous preterm birth. Folic acid supplementation would not increase the risk of multiple births or miscarriage.
      Marker Papers 1. Berry RJ, Li Z, Erickson JD, Li S, Moore CA, et al. Prevention of neural-tube defects with folic acid in China. N Engl J Med. 1999; 341:1485-1490.
      2. Gindler J, Li Z, Berry RJ. Folic acid supplements during pregnancy and risk of miscarriage. Lancet. 2001; 358(9284): 796-800
      3. Myers MF, Li S, Correa Villasenor A, et al. Folic acid supplementation and risk for imperforate anus in China. Am-J-Epidemiol. 2001; 154(11): 1051-6.
      4. Li Z, Gindler J, Wang H, et al. Folic acid supplements during early pregnancy and likelihood of multiple births: a population-based cohort study. Lancet. 2003; 361(9355): 380-4.
      5. Li S, Chao A, Li Z, et al. Folic acid use and nonsyndromic orofacial clefts in China: a prospective cohort study. Epidemiology. 2012;23(3):423-32.
      6. Li Z, Ye R, Zhang L, et al. Folic acid supplementation during early pregnancy and the risk of gestational hypertension and preeclampsia. Hypertension. 2013; 61(4):873-879.
      7. Li Z, Ye R, Zhang L, Li H, Liu J, Ren A. Periconceptional folic acid supplementation and the risk of preterm births in China: a large prospective cohort study. Int J Epidemiol. 2014;43(4):1132-9.
      Strength The cohort is the largest cohort in studies on folic acid intervention in the world. In addition, at present, there are still 120, 000 women's blood samples stored in the research.
      Weakness At present, the cohort only underwent one physical development visit in 2000 (when the child was 3-6 years old). There was no follow-up data.