Findings from a new study in China show that consumption of folic acid as a vitamin pill to reduce the risk of neural tube birth defects is safe, and does not increase a woman’s risk of having a miscarriage.

The study published in the 8 September 2001 issue of The Lancet, was conducted by the Centers for Disease Control and Prevention (CDC) and Peking University Health Sciences Center, China. It focuses on women who had taken part in a project to prevent neural tube birth defects by taking 400 micrograms of folic acid a day in pill form.

Researchers found that the risk for miscarriage was essentially the same among women who did and did not take the folic acid vitamin pill. This study was the first to evaluate the risk of miscarriage in a large population of young women who were pregnant for the first time, and who had documented records of precisely how much folic acid they took before and during early pregnancy. In addition, women in this study took only folic acid, without other added vitamins.

For this evaluation, the authors compared the rates of miscarriage among women who took the folic acid pill as part of the public health campaign and those who did not take folic acid. The rate of miscarriage was slightly lower (9.0 percent) for women who took any folic acid before and during early pregnancy than for women who did not take any folic acid (9.3 percent).

The project, conducted in China, was a collaborative effort between lead author Jacqueline Gindler, M.D., and other researchers from CDC’s National Center on Birth Defects and Developmental Disabilities and Dr. Zhu Li, M.D., M.P.H., with researchers from Peking University Health Sciences Center, China.

"By taking folic acid before becoming pregnant, a woman can improve the chances that her unborn child will be born healthy, by reducing the risk of a neural tube birth defect," said Dr. Gindler. "Women can take folic acid with confidence, knowing that it is safe, and will not increase their risk of having a miscarriage."

Folic acid is widely recommended in the United States and throughout the world to prevent the occurrence of devastating neural tube birth defects, which, in the United States, affect an estimated 4,000 pregnancies each year. Researchers know that folic acid consumption is an effective way to prevent many of these birth defects if it is consumed before pregnancy.

"This study provides the evidence that taking folic acid pills before and during early pregnancy is safe, and is not associated with an increase in the risk for adverse pregnancy outcomes such as miscarriage," said Dr. Gindler