CHICAGO—Women taking multivitamins during and after pregnancy may have a greater chance of seeing improved birth outcomes, according to new research published in the late-December issue of JAMA (2014;312(24):2649-2658). While the study results showed no significant improvement in its primary endpoint of all-cause mortality, there were significant improvements in secondary outcomes including birth weight and preterm birth rate.
Researchers from Johns Hopkins University, Baltimore, the JiVitA Project, Bangladesh, and the Centers for Disease Control and Prevention (CDC), Atlanta, looked at the effects of mothers taking a basic multivitamin during and after pregnancy on all-cause mortality, as well as stillbirths, preterm births and birth weight. The Bangladesh-located study included 44,567 pregnant women who gave birth to 28,516 live babies. From early pregnancy (median of 9 weeks gestation) through 12 weeks postpartum, the women took either iron-folic acid alone or a multi-nutrient formula based on Recommended Daily Allowance (RDA) levels. Researchers assessed all-cause mortality through six months postpartum as well as stillbirth, preterm birth (<37 weeks) and birth weight (<2,500 g/5.5 Lbs.).
The lack of significant effect on all-cause mortality may reflect the numerous confounding factors, as acknowledged by the study authors: “Reasons for a null effect on postnatal survival after improvement in some birth outcomes with antenatal multiple micronutrient supplement use remain unknown but may reflect a complex interplay between maternal and newborn sizes and differential responses to supplementation by causes of death."
The real strong value of the study is in the improvements to key birth outcomes, including preterm birth and birth weight, according to Duffy MacKay, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition (CRN).
“This is a positive study, a Christmas present for the multivitamin community," MacKay said.
“These are outcomes we know are associated with both short- and long-term negative implications," he noted. “In this study, we have very a meaningful 15-percent reduction preterm birth, which is incredible, and a 12-percent reduction in low birth weight."
Mackay also assured the results on stillbirths (about a 10-percent reduction) were promising, even if they were deemed non-statistically significant by the publication authors—P value was adjusted for multiple comparisons. The multivitamin group had 648 stillbirths compared to 716 stillbirths in the iron-folic acid group. The stillbirth rates (per 1,000) were 43.1 and 48.2, respectively.
MacKay called the study a validation of previous evidence showing that when you fill nutrient gaps, when you have good nutrition during pregnancy, there are positive outcomes. “Again, these positive outcomes are associated with complications and costs, such as hospital stays, respirators, etc.," he explained, stressing the importance of making sure at-risk populations, such as the rural Bangladesh population of this study, fill their nutrient gaps. He reminded the nutrient gap issue is not just in poor countries, but also in wealthy western countries, suggesting programs addressing nutrient shortfalls, such as allowing food stamp purchases of multivitamins, would produce these positive birth outcomes and benefit mothers, infants and society.
One aspect of the publication that excited MacKay was the authors’ discussion of possible mechanisms behind the positive birth outcomes. Recognizing the possibility of mechanisms beyond the iron-folate metabolic pathways, the authors considered influences on immune function, including maternal, placental and fetal inflammation, as well as potential effects on oxidative metabolism that can affect placental function and hypertension. What stood out for MacKay was the mention of a possible effect on epigenetic programming, which the authors said could “improve nutrient utilization and embryo-fetal growth and development."
“I’m glad this is showing up in JAMA; I’m glad a top-tier medical journal felt this was quality research to put out there," MacKay said. He called the study well-designed and well-executed, and applauded the vast resources committed to the research. “I am hopeful there is a lot of data accumulated and we’ll see additional publications, studies and questions answered just from this cohort," he said.
For more information on the study, visit the JAMA website.
Read Mackay’s official statement at CRNUSA.org.