Babies born in resource-poor rural and semi-rural communities have a high risk of stunting, that is, being born short for their gestational age. Rates as high as 60% have been documented in one indigenous population in Guatemala. Stunting at birth predicts increased infant and child mortality as well as ongoing growth retardation. Growth retardation in turn carries a higher risk for impaired brain function and loss of economic productivity. In female infants, growth failure presents a greater reproductive risk for themselves and their eventual children due to intrauterine growth restriction. The issue is primarily a consequence of inadequate nutrition, and is considered to be a major public health challenge in developing nations. However, nutrition interventions carried out during the infant and toddler stages have had only limited success in either treating or preventing growth failure. Those aimed at maternal nutrition during pregnancy, primarily focusing on micronutrients, have produced positive, albeit modest, effects on newborn size. Interventions prior to conception have not been well studied in humans, but animal studies have shown promise.
A new study published in The American Journal of Clinical Nutrition aimed to test the effect of an inexpensive, dairy-containing supplement on newborn length and overall birth size when given either prior to conception or during pregnancy. This study is unusual in that it looked at the effect of supplementing both macro- and micronutrient intake. The supplement is described as “a multi-micronutrient fortified lipid-based supplement composed of dried skimmed milk, soybean and peanut extract, sugar, maltodextrin stabilizers, and emulsifiers.” Each package weighs less than an ounce and provides vitamins, minerals, protein, and fats that may be missing in the women’s diets. It is blended into a peanut butter-like consistency and can be eaten alone or mixed with other foods. The paste is also water-free and shelf-stable for up to 18 months in hot, humid environments and is acceptable to vegetarian populations. The supplement is a modified form of Nutributter, a formulation created at UC Davis for use by children at risk of malnutrition. Nutributter was inspired by the success of the original therapeutic nutrient paste, Plumpy’nut, a French concoction that consists of blended peanuts, skimmed milk powder, oil, sugar, and vitamins, and that has proven highly successful at treating acute malnutrition in famine emergencies. The paste formulation is key, because previous treatments relied upon mixing with local water, which in many cases was a source of pathogens.
The study consisted of three experimental groups: one in which the intervention was given starting at least three months prior to pregnancy, one in which the intervention began in the late first trimester, and a control group that received no intervention. In both treatment groups, the supplement continued through birth. A second fat- and protein-containing supplement was also given to women in the treatment groups with a low BMI, as well as those who failed to gain enough weight during the second or third trimesters of pregnancy. The study took place across rural and semi-rural locations in four developing countries: the Democratic Republic of Congo, Guatemala, India, and Pakistan. All participants were between the ages of 16 and 35, and had given birth fewer than six times. Women with iron deficiencies were treated prior to acceptance in the study, and no one was excluded based on height, weight, or body mass index. The mothers also varied in diet, culture, socioeconomic status, and level of education. Following a live birth, newborns were measured within 48 hours for length, weight, and head circumference.
Over 2400 newborns were measured across the study. The researchers found a positive effect on both length and weight between the treatment and control groups, leading to a decrease in stunting of more than a third and a 22% lower incidence of infants that were small for their gestational age, a result that occurred despite maternal weight gain during pregnancy that was low relative to international recommendations. Surprisingly, researchers found no difference in outcome between the infants whose mothers had begun intervention prior to conception and those who had begun late in the first trimester.
“In settings with high rates of poor growth in children’s height, including stunting, we found that improving mothers’ nutrition either before they became pregnant or by the end of the first trimester of pregnancy resulted in their babies being longer and having better birth weights,” explains Dr. Nancy Krebs, a professor of pediatrics at the University of Colorado School of Medicine and one of the study’s co-authors. “Since women often do not recognize that they are pregnant until after the first trimester, these results support strategies to improve women’s nutrition before they conceive.”
A weakness of the study was the absence of gestational age data for one of the four study populations, the Democratic Republic of Congo, meaning those measurements could not be corrected for gestational age, which may have made improvements there less pronounced. It’s possible, the authors point out, that the differences in outcome between the two treatment groups won’t be seen until the next generation of children born to the female babies included in this study. In multiple studies, the effects of malnutrition take several generations to “wash out,” and a review of 14 studies on intergenerational associations in birthweight found that for each 100 g increase in maternal birthweight, there was a further 10–29 g increase in offspring birthweight. There was also evidence that these increases are largely independent of the postnatal growth of the parents, underscoring the importance of prenatal nutrition to later generations — By Erin Zimmerman, International Milk Genomics Consortium