Doctors recommend folic acid supplementation for expecting mothers looking to reduce their child’s risk for low birth weight, which can lead to various future health complications, including diabetes, high blood pressure, obesity, heart disease, and mental health conditions. A recent study published in An International Journal of Obstetrics and Gynaecology (BJOG) suggests the optimal time for taking folic acid during pregnancy to reduce a child’s risk for small gestational age (SGA) at birth is before becoming pregnant.

"The population study is the largest database to look at the timing of folate intake and the risk of a baby being SGA," John Thorp, BJOG deputy editor-in-chief, said in a statement. "The findings of this study are of particular importance because growth restriction is known to be associated with poor short and long term outcomes, and currently there are no established preventative treatment options for SGA."

Khaled Ismail Professor of Obstetrics and Gynaecology at the University of Birmingham and his colleagues recorded the time of commencement for folic acid supplementation with 39,416 pregnancies, 25.5 percent of which started taking the B vitamin before conception. Of the mothers included in the study, 42 percent were firsttime mothers, 81.7 percent were non-smokers, the average maternal age was 28.7 years, and the average BMI was 24.7 percent. Previous studies have shown that rates of women taking folic acid before conception are somewhere between 14.8 and 31 percent.

By the end of the study, the highest rate of babies born with SGA occurred with mothers who did not take folic acid at all during pregnancy. Taking folic acid before conception led to fewer incidences of SGA compared to starting supplementation after conception. Although both the U.S. and the UK recommend folic acid supplementation prior to becoming pregnant, the authors of the study fear not enough women are heeding their doctor’s words.

"Increased uptake of folic acid prior to pregnancy and throughout the first trimester could have significant public health benefits given the poor outcomes associated with SGA babies," Ismail said. "New strategies are therefore vital to improve the lives of both mothers and babies."

According to the Centers for Disease Control and Prevention, 400 micrograms of folic acid every day, starting at least one month before getting pregnant is the recommended dosage for expecting mothers looking to prevent major birth defects of their infant’s brain and spine. While folic acid supplements are highly recommended for women trying to get pregnant, women who are not trying to become pregnant should also consider a steady supplementation to promote healthy cell growth.

Source: VA Hodgetts, RK Morris, A Francis, J Gardosi, KM Ismail. Effectiveness of folic acid supplementation in pregnancy on reducing the risk of small-for-gestational age neonates: a population study, systematic review and meta-analysis. BJOG. 2014.