Women who consume folic acid supplements around the time of conception are not at an increased risk of miscarriage, conclude authors of a population-based study published in this weke’s issue of THE LANCET.
Although it is well known that folic acid supplements can reduce the risk of infant neural-tube defects (NTDs), its effects on other pregnancy outcomes are unclear; a previous study suggested that folic acid could increase the risk of miscarriage by up to 16%.
Jacqueline Gindler and colleagues from the Centers for Disease Control and Prevention, Atlanta, USA, and Peking University Health Sciences Center, China, studied Chinese women who had taken part in a folic-acid campaign to prevent infant NTDs and who had registered in this campaign before they became pregnant for the first time. The investigators assessed the risk for miscarriage among women who had confirmed pregnancies and who had or had not taken pills containing only 400 µg of folic acid before and during early pregnancy.
The overall rate of miscarriage was 9.1% (2155 of 23 806 women). The rates of miscarriage among women who had and had not taken folic acid pills before and during the first three months of pregnancy were 9% and 9.3%, respectively. Demographic data of the women and the average time at miscarriage were similar between the two groups.
Robert Berry (one of the investigators) comments: "In this population-based study of a cohort of women whose use of folic acid supplements while pregnant had been previously documented and who had been pregnant for the first time, we found no evidence that daily consumption of 400 µg of folic acid before and during early pregnancy influenced their risk for miscarriage."
Contact: Dr Robert J Berry, Centers for Disease Control and Prevention, National Center for Environment Health, Division of Birth Defects and Pediatric Genetics, 4770 Buford Highway Mailstop F-45, Atlanta GA 30341, USA; T) 1-770-488-3502; F) 1-770-488-7197; E) rjb1@cdc.gov or CDC Media Relations Division; T) 1-404-639-3286.
Journal
The Lancet