Offspring BMI and lipid profiles following assisted reproductive technology: a comparative study of underweight and normal-weight mothers

The early developmental environment is associated with long-term metabolic health outcomes in children. A large proportion of underweight women tend to become pregnant via assisted reproductive technology (ART). However, the correlation between maternal prepregnancy underweight status and metabolic health in ART-conceived offspring remains poorly understood. The present study aimed to elucidate the associations of maternal underweight status with offspring development and lipid profiles, as well as to examine ART’s potential interaction in this process. The prospective cohort study included children conceived via ART at the Hospital for Reproductive Medicine Affiliated to Shandong University between April 2007 and August 2014. A total of 2,506 mother–offspring pairs, encompassing 3,496 visits, were analysed. Participants were divided into the following two groups based on the maternal body mass index (BMI): the normal weight group (18.5 ≤ maternal BMI < 24 kg/m2) and the underweight group (maternal BMI < 18.5 kg/m2). The BMI z-scores and serum lipid profiles of offspring aged 4–10 years were assessed. Compared with those of controls, the offspring of underweight mothers had significantly lower BMI z-scores (mean difference: -0.55; 95% confidence interval [CI]: -0.71 to -0.38). Interaction analysis revealed no significant interaction effect between ART treatment (fertilization mode, embryo transfer stage, or embryo freezing) and maternal BMI status on offspring BMI and lipid profiles. However, a significant interaction effect was observed between maternal BMI status and offspring sex on offspring lipid profiles (interaction P values: 0.026 for total cholesterol and 0.021 for low-density lipoprotein cholesterol [LDL-c]). Compared with the control offspring, the female offspring of underweight mothers had higher total cholesterol levels (mean difference: 0.16; 95% CI: 0.02 to 0.29) and LDL-c levels (mean difference: 0.13; 95% CI: 0.02 to 0.25), while no such effects were found for male offspring (total cholesterol mean difference: -0.05; 95% CI: -0.17 to 0.09; LDL-c mean difference: -0.04; 95% CI: -0.15 to 0.07). In the present study, there was an association between prepregnancy maternal underweight status and reduced BMI among ART-conceived offspring, and significant sex-specific differences in offspring lipid profiles were identified. Moreover, the analysis excluded any interaction effects between ART procedures and maternal BMI status on these outcomes. These findings emphasize the association of prepregnancy maternal underweight status with lower BMI and altered lipid profiles in ART-conceived offspring, providing crucial insights for preconception care and targeted postnatal prevention strategies.