In a nutshell
This study looked at whether folic acid supplements increased fertility. The authors found that women taking folic acid were more likely to become pregnant within 12 months.
Some background
Folic acid is a recommended supplement for women planning pregnancy. It is included in prenatal vitamins and most women’s multivitamins. In the first months of pregnancy, folic acid is vital for early brain development.
Studies suggest that folic acid may also increase fertility. Women who take multivitamins with folic acid are more likely to ovulate (produce eggs). Previous studies found that women trying to conceive had somewhat higher pregnancy rates when taking folic acid supplements. The impact of folic acid on fertility remains under investigation.
Methods & findings
This study followed 3895 women who were planning a pregnancy. These women had been trying to get pregnant for 6 months. During the study, participants were given an online survey twice a month for up to 1 year.
Overall, 65.7% of participants used folic acid supplements or a multivitamin with folic acid. 32.7% of participants did not use any supplements.
69% of women became pregnant within 12 cycles of completing surveys. However, some women dropped out of the study before 12 months or stopped trying to conceive. After adjusting for these factors, the estimated 12-month pregnancy rate was 83%.
Women who used folic acid were 15% more likely to become pregnant within 12 cycles. Among women with irregular periods, women using folic acid were 35% more likely to conceive. Folic acid increased the chances of pregnancy by 36% among women with short cycles (less than 27 days). Among women with long cycles (more than 30 days), folic acid increased the chances of pregnancy by 34%.
The bottom line
This study found that women taking folic acid were more likely to become pregnant within 12 months. Folic acid had a particular benefit for women with irregular cycles. This was particularly true for women with short, long, or irregular cycles.
The fine print
Data was collected from self-reported surveys online, which may bias the results. Also, these results may not apply to women with very long cycles, such as women with PCOS (polycystic ovarian syndrome).
What’s next?
Talk to your doctor about the potential benefits of folic acid.