Impact of Iron/Folic Acid Versus Folic Acid Supplements During Pregnancy on Maternal and Children's Health: A Randomized Controlled Trial in China

Iron deficiency (ID) is the world's most common single nutrient disorder, differentially affecting pregnant women and infants everywhere. The study was conducted in China, a rapidly developing country where ID often occurs among pregnant women and infants in the absence of generalized undernutrition. The study was a collaboration between Peking University First Hospital and three local hospitals (Sanhe Maternity and Child Health Care Center [MCHC], Sanhe General County Hospital, and Sanhe Hospital of Traditional Chinese Medicine). Eligible pregnant women were enrolled from June 2009 through December 2011 and randomized in a 1:1 ratio to receive iron and folic acid or folic acid only. The study protocol was approved by the institutional review board of Peking University First Hospital, Beijing, China. Women were recruited (n=2367) at their first prenatal visit at Sanhe MCHC. Those with uncomplicated singleton pregnancies and first prenatal visits ≤ 20 weeks gestation were invited to participate. Women were randomized and received 2 supplements: iron/placebo and folic acid. Project personnel instructed the participants to take two capsules per day (one of each kind of supplement) from enrollment to delivery. Participants received a 3-month supply of each supplement upon enrollment and at the second study visit (26-30 weeks). The number of doses received and consumed or missed was recorded by project personnel. The primary outcomes were maternal iron status at follow-up visits (26-30 weeks and 36-40 weeks), cord-blood iron status, and infant gestational age and birth weight. Data analysis compares pregnancy iron level between two study groups and how it relates to pregnancy outcomes, including pregnancy and delivery complications, preterm rate, perinatal death rate, and birth rate. Data analysis also includes evaluating pregnancy nutrition conditions and analyzing associations with weight changes during pregnancy, and rates of pregnancy diabetes, pregnancy high blood pressure, fetus growth restriction, low birth weight, and fetal macrosomia. Up to 75% of pregnant women worldwide are anemic, with about half due to ID. The public health implications of study findings could be profound.