Start taking 0.4 mg of folic acid every day when you begin trying to get pregnant, and keep taking it until the end of the first 3 months of pregnancy
- High value
- Evidence A
- Buys life
- For: Pregnant or trying
- Free
- Takes minutes
- Some willpower
In plain words
Taking one folic acid tablet a day from before pregnancy through early pregnancy cuts the chance of a neural tube defect in the baby by about 70%. Neural tube defects are birth defects such as anencephaly and spina bifida. For someone who has already had one baby with such a defect, the chance of another affected baby falls to about one third of what it was.
- Cost
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A few dozen CNY a bottle. Rural women pay nothing, because the state's free folic acid supplement program (增补叶酸项目) provides it. One tablet a day; the hard part is remembering every day.
- What you get
-
A Cochrane systematic review pooled 5 trials and 6708 births, and rated the quality of the evidence as high. Taking folic acid daily around the time of pregnancy gave a risk of fetal neural tube defects of RR 0.31 (95% CI 0.17 to 0.58, the plausible range), about 70% lower. For someone who had already had a baby with a neural tube defect, the risk of another affected baby was RR 0.34 (95% CI 0.18 to 0.64), down to about one third. Grouped by population, 0.4 mg and higher doses made no difference. Folic acid alone and a multivitamin also made no difference.
- Notes
-
The key is “start before you get pregnant.” The baby's neural tube closes within 28 days of conception. By the time a test shows you are pregnant, most of that period has already passed. So if you plan to have a baby, begin 3 months ahead. In the same pooled study, folic acid had no clear effect on cleft lip and palate, congenital heart disease or miscarriage, so don't expect it to prevent anything else. A pregnant woman on a fully vegan diet also needs vitamin B12 every day; see §20.14 (take vitamin B12 daily if you eat vegan).
- Evidence grade
- A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.
- Sources
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- De-Regil LM, Peña-Rosas JP, Fernández-Gaxiola AC, Rayco-Solon P (2015). Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews, (12), CD007950. https://doi.org/10.1002/14651858.CD007950.pub3
Mentioned in
Translated from the Chinese original. Original book, section 27, tip 1. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer