A British study finds that women who take a prenatal supplement at the end of their pregnancy are more likely to give birth prematurely.
Researchers said there are more risks of giving birth prematurely with vitamin supplements taken during the third trimester of pregnancy.
Dr. Nigel Simpson of the University of Leeds in the U.K. is one of the authors of the study. He says, "These supplements are available over-the-counter in the United Kingdom and frequently promoted as being beneficial for mums-to-be."
However, several specialists say there are weaknesses in the study. There were 1,300 participants between 2003 and 2006. The United Kingdom no longer recommends that women take prenatal supplements throughout their pregnancy.
Study authors note in the British Journal of Obstetrics and Gynecology that "women in the study were already getting enough of most vitamins and minerals contained in prenatal supplements from their diets, with the exceptions of vitamin D, iron, folate, selenium and iodine."
Dr. Simpson says that pregnant women really don’t need to take prenatal vitamins past the first three months of pregnancy.
He adds: "Eating a healthy diet is likely to be sufficient for expectant mums."