Variants in BMI-Associated Genes and Adrenergic Genes are not Associated with Gestational Weight Trajectory

Objective: The aim of this study is to define the association between a genetic risk score (GRS) that combined the effect of multiple BMI-associated variants and gestational weight trajectory. Because pregnancy is a state of sympathetic activation, the association between gestational weight trajectory and variants in adrenergic pathways previously associated with weight was examined. Methods: In a previously defined cohort of pregnant women with (n = 1,504) and without gestational diabetes (GDM) (n = 435), weight trajectory was calculated using all weights during pregnancy. A GRS for BMI (GRS_BMI) was calculated using 31 common variants associated with BMI, and 10 variants in the adrenergic pathways were genotyped. Clinical and genetic factors were studied using generalized linear models. Results: Prepregnancy BMI was associated with the GRS_BMI(P = 9.3 × 10⁻¹¹) and parity (P = 4.54 × 10⁻¹⁷). The GRS_BMI was associated with gestational weight trajectory in women with and without GDM (P = 0.041 and P < 0.0001, respectively); however, when prepregnancy BMI was included in the models, the associations disappeared (P > 0.05). Variants in adrenergic genes were not associated with gestational weight trajectory. Conclusions: A GRS for BMI was associated with prepregnancy BMI but was not independently associated with gestational weight trajectory in women with and without GDM. Selected variants in adrenergic genes were not associated with gestational weight trajectory.