Shrestha D, et al. - Maternal genetic risk associations for obesity and fetal weight were analyzed at the end of the first (13 weeks 6 days), second (27 weeks 6 days) and third (40 weeks 0 days) trimesters of pregnancy among four race/ethnic groups in the United States. Maternal genetic risk score (GRS) was calculated as the sum of 189 BMI-increasing alleles for 603 white, 591 black, 535 Hispanic and 216 Asian women and was classified into high or low GRS. At the end of the second and third trimesters among Hispanic women, high GRS vs low GRS was linked to increased fetal weight. Among Asian women, high GRS was linked to increased weight among male fetuses but reduced weight among female fetuses. In Hispanic women with normal prepregnancy weight, adequate first trimester gestational weight gain (GWG), or inadequate second trimester GWG, the effect of GRS has been stronger. Overall, the authors concluded that maternal obesity genetic risk was linked to fetal weight with potential effect modifications by maternal prepregnancy BMI, GWG, and fetal sex.