The research, published in JAMA, suggests that taking a supplement containing 15 essential micronutrients is superior to the current standard of care in many developing countries, which calls for pregnant women to take supplements containing iron and folic acid.
Led by researchers at Johns Hopkins Bloomberg School of Public Health, USA, the large randomised-controlled trial found that a multivitamin given daily to pregnant women in rural Bangladesh reduced pre-term births, increased infant birth weight and resulted in healthier babies overall, compared to a supplement containing just iron and folic acid.
"Our study shows that women in undernourished societies should be given a multiple micronutrient supplement during pregnancy," said study leader Professor Keith West Jr. "It increases birth size because the babies stay in the womb longer and when that happens they are born a little larger and better equipped to handle life outside the womb.”
Indeed, the RCT data showed that women who received the larger number of micronutrients were 15% less likely to give birth prematurely or prior to 37 weeks of gestation, while also reducing the number of babies born with a low birth-weight.
“There is clear evidence of benefit,” said West Jr.
The research team recruited around 45,000 pregnant women in rural Bangladesh beginning in December 2007, and assigned them to receive either a daily multivitamin or an iron-folic acid supplement.
The women were followed through their pregnancies and, for those who gave birth, at one, three and six months after their children were born. There were roughly 14,000 live births in each group in the trial, with other pregnancies lost to miscarriage, abortion or stillbirth, said the team.
The primary outcome was all-cause infant mortality through 6 months (180 days), while pre-specified secondary outcomes in the analysis included stillbirth, preterm birth (less than 37 weeks), and low birth weight ( less than 2500 g).
Analysis of the results from the trial showed that at 6 months, multiple micronutrients did not significantly reduce infant mortality; “there were 764 deaths (54.0 per 1000 live births) in the iron–folic acid group and 741 deaths (51.6 per 1000 live births) in the multiple micronutrient group,” stated the team.
However the team noted that babies born to mothers who had been given the multivitamin were 15% less likely to give birth prematurely, 12% less likely to be born at a low birth weight, and 11% less likely to be stillborn.
The team also found that on average, infants born to mothers in the multivitamin group were born two to three days later than those in the iron-folic acid group, giving them more time to bulk up before birth, and were born an average of 55 grams larger.
"In countries like the United States, where there is already better vitamin and mineral nutrition, women often start taking micronutrient supplements as soon as they become pregnant, if not before," says West. "But they don't in the developing world.”
“Vitamin and mineral supplements are more costly - probably several cents per tablet more - so in cultures where families make only a few dollars a day we need to be able to show that the investment is worthwhile in terms of having an impact on the health of mothers and their children.”
“This study provides the needed evidence."
Volume 312, Issue 24, Pages 2649-2658, doi: 10.1001/jama.2014.16819
“Effect of Maternal Multiple Micronutrient vs Iron–Folic Acid Supplementation on Infant Mortality and Adverse Birth Outcomes in Rural BangladeshThe JiVitA-3 Randomized Trial”
Authors: Keith P. West Jr, Abu Ahmed Shamim, et al