Multivitamins During Pregnancy Help Avoid Underweight Babies

By Margarita Nahapetyan

Future moms-to-be who take multivitamins during pregnancy, significantly lower the risk of delivering an underweight baby, researchers from Canada have reported this week.

One of the biggest risks to newborn babies is to be born too early and with too little weight. And, unfortunately, doctors do not know yet why some babies are being born pre-term. These babies are at much greater risk of mortality and later disability, and their care is often long and costly. That is why, Dr. Prakesh Shah, a lead investigator of the study, a neonatologist at Mount Sinai and associate professor at the University of Toronto and colleagues, set to find out whether it is best for future mothers to take a daily multivitamin supplements during pregnancy or to take daily supplements of folic acid in combination with iron - as recommended by the World Health Organization.

After a thorough analysis of more than a dozen well designed studies, including the most recent ones. All those studies examined the relationship between vitamin and mineral supplementation and birth outcomes, the investigators came to the conclusion that prenatal multi-micronutrient supplementation was associated with much less risk of small birth weight as well as with improved birth weight, when compared with iron-folic acid supplementation.

To be more specific, in their study, Canadian team examined the records of more than 36,000 women and their babies. They looked at this particular aspect of multivitamin use, and compared women in the two groups - one group taking multivitamins and another group taking just iron combined with folic acid. And there were another set of studies in which women, who were taking multivitamin supplements were compared to to their counterparts taking placebo alone.

According to Dr. Shah, when compared to placebos, or sugar pills, multivitamins were found to be effective in reducing low birth weight, and when compared with iron and folic acid alone, multivitamins were found to lower the risk of low birth weight by 17 per cent. "It is a very significant effect," Dr. Shah said.

It is believed that multivitamins boost immune function in women, improve their overall nutritional status and improve growth of fetus. The study revealed that overall, the birth weight of infants was 54 grams higher, on average, among babies of mothers who were taking multivitamins than among those who took iron-folic acid supplements alone.

It is estimated that of the total of 133 million babies being born worldwide every year, 15.5 per cent, or about 20 million, are babies with low birth weight. Canadian researchers estimate that if all pregnant women were given multivitamin supplements, there would be 1.5 million fewer low birth-weight babies born every year.

The World Health Organization currently recommends, based on a review it did in 2005, that all pregnant women take iron and folic acid supplements in order to improve fetal growth and to prevent spina bifida and neural tube defects. When the organization compared studies available at that time, it came to the conclusion that multivitamin supplements did not bring any extra benefit over folic acid and iron alone, the Canadian researchers say. But since that time, several randomized, controlled studies have been carried out, finding the positive effect of multivitamin use during pragnancy.

Dr. Shah says that it is time the WHO updates its recommendations for prenatal nutrition. "We do not need to do more and more studies because... it is not ethical to get the women now to take only iron-folic acid and being part of the study," Dr. Shah said. "So we are challenging the WHO that we need to create a policy change..."