In the group of non‐NF1 infants of NF1 mothers, the difference was significant among all births since 1987 (13.19 vs. 13.89, −0.71 [−0.95 to −0.47]), and among births since 2004 after adjustment of the analysis for gestational diabetes, maternal height, and maternal weight (12.99 vs. 13.90, −0.91 [−1.45 to −0.36]). This evidence concerns the gene NF1 and gestational diabetes.