A recent Poster session supplement to the American Journal of Obstetrics & Gynecology examined the effect of maternal diet on birth weight of infants.
It is understood that babies born to obese women are more frequently on the “extreme” ends of the birth weight scale (i.e. either
significantly overweight or significantly underweight), there hasn’t been much by way of research specifically on the effect of maternal diet on the birth weight of infants.
This study recruited 11 normal weight, 15 overweight, and 15 obese women prior to pregnancy and followed them through to full term.
Pre-pregnancy body mass index (BMI), dietary assessments (via questionnaires), and several body composition measurements were taken.
Dietary assessments were scored using the Health Eating Index-2010 (HEI-2010).
The same measurements were taken after on or 37 weeks during gestation, plus measurements on body water content and bone mineral content.
Infant and placental weight measurements were taken at time of delivery.
- Increased HEI-2010 scores were inversely associated with infant birth weight, regardless of the BMI of the mother.
- Healthier diet patterns (i.e. Mediterranean-style or plant-based diets) by the mother are associated with lower infant birth weight.
- Poor diet patterns (i.e. Western diet or diet rich in sweets and foods with poor nutritional content) by the mother are associated with higher infant birth weight.
- There was no association between caloric intake, % fat intake, % protein intake, % carbohydrate intake, maternal fat mass, and percent body fat on infant birth weight was found.
The results of this study indicate that no matter the weight or BMI of the mother, infant birth weight is associated with the particular diet that mother ate during her pregnancy.
Perhaps the mother may not have eaten the best food throughout her life prior to pregnancy, possibly resulting in being overweight or obese, however, if that mother consumed a very healthy diet during her pregnancy, her baby was more likely to be a healthier birth weight than if she had continued to eat a poor diet during her pregnancy.
These results suggest that stressing healthy eating during pregnancy, regardless of the size of the mother, is recommended in order to prevent overweight babies at term.
Marshall, N., Murphy, E., Haas, K., King, J., Purnell, J., and Thornburg, K.2015. Healthier maternal diet index score is associated with healthier birth weight. American Journal of Obstetrics and Gynecology Supplement 210: S118.