More and more young obese women get pregnant after undergoing gastric bypass surgery (GBP) but little is known about weight development in their offspring. The first aim of this study was to investigate weight development of children whose mothers have undergone GBP before pregnancy and compare them to age specific reference values in Sweden. Second aim was to study the frequency of small for gestational age (SGA) in this population. Materials and methods: Weight of offspring (38 male and 28 female) where the mother had undergone GBP before pregnancy were studied from birth up to 18 months of age and compared to age-specific reference values in Sweden.
The boys to mothers who had undergone GBP before pregnancy weighed more than Swedish reference values at 6 months, 8.44 ± 1.18 kilogram (kg) (n = 35) vs. 7.98 ± 0.81 kg (n = 1388; p = 0.001), and less at 18 months, 11.54 ± 0.93 kg (n = 19) vs. 12.27 ± 1.19 kg (n = 862; p < 0.001). The girls to mothers who had undergone GBP before pregnancy weighed more than Swedish reference values at 6 months, 7.84 ± 1.00 kg (n = 28) vs. 7.50 ± 0.77 kg (n = 1375; p = 0.020). Frequency of SGA was 3.0%.
No clear pattern was found concerning the short-term weight development of the children. However, studies with larger material and more follow up time must be performed.