According to study results published in the Journal of Bone and Mineral Research, there is a slight association between maternal gestational weight gain and offspring bone mineralization in underweight/normal weight women, but not in overweight/obese women.
Researchers conducted this prospective cohort study to examine the relationship between gestational weight gain and bone mineralization in offspring at 7 years and to assess the modifying effects of early pregnancy body mass index. Data were analyzed from 2167 mother-child pairs who underwent whole-body dual-energy x-ray absorptiometry when the child was 7 years of age.
Of the total population of mothers, 35.8% were classified as overweight or obese. The overall mean maternal gestational weight gain was 13.2 ± 5.3 kg and was significantly greater in the underweight/normal weight group than in the overweight/obese group (14.1 vs 11.7 kg, respectively; P <.001). According to Institute of Medicine recommendations, 36.6% of all included mothers gained excessive weight during pregnancy and 23.7% gained too little weight.
In underweight/normal weight mothers, gestational weight gain was determined to be associated with slightly increased bone measures in offspring at 7 years (per 5 kg of gestational weight gain: bone mineral content, 0.07 standard deviation [SD]; areal bone mineral density, 0.10 SD; size-corrected bone mineral content, 0.11 SD; and height, 0.05 SD).
However, in mothers with excess weight in early pregnancy, the researchers discovered gestational weight gain had no significant effect on offspring bone health (per 5 kg of gestational weight gain: bone mineral content, 0.02 SD; areal bone mineral density, 0.02 SD; size-corrected bone mineral content, 0.01 SD; and height, 0.02 SD).
In addition, no group demonstrated an advantageous effect of gaining weight above the Institute of Medicine recommendations.
Several limitations were noted for this study, including an inability to generalize findings to a broader population.
“Given the well-known adverse implications of excessive [gestational weight gain] for both mother and offspring on a wide range of outcomes, our findings support that women who are encouraged to follow [Institute of Medicine] weight gain recommendations during pregnancy should not expect a deleterious effect on the child’s skeletal health,” said the researchers.
Monjardino T, Henriques A, Moreira C, et al. Gestational weight gain and offspring bone mass: Different associations in healthy weight versus overweight women [published online November 6, 2018]. J Bone Miner Res. doi:10.1002/jbmr.3587