To determine the obstetric and neonatal outcomes of pregnant patients having undergone laparoscopic sleeve gastrectomy (LSG) in the previous 12 months.This retrospective and observational study included 144 pregnant women: 48 had pregnancies within 12 months after LSG (Group A), 42 became pregnant more than 1 year after surgery (Group B) and 54 obese pregnant women who had a body mass index (BMI) >30 kg/m , were categorized as the control group because they did not undergo surgery (Group C). The participants' early gestational BMI, predelivery BMI and gestational weight gain were determined and the obstetric and neonatal outcomes of the groups were compared.The time interval from surgery to conception was 7.8 ± 3.4 months and 25.8 ± 13.4 months for Groups A and B, respectively (P < 0.01). There were no significant differences in the rates of gestational hypertension, pre-eclampsia, preterm delivery and cesarean section between the groups. The number of patients with gestational diabetes mellitus was significantly higher in Group C than in Groups A and B (P = 0.004). The number of large-for-gestational-age infants was higher in Group C than in Groups A and B (P = 0.046). The number of small-for-gestational-age infants was significantly higher in Group A than in Groups B and C (P = 0.025).Pregnancy within one year after LSG is related to an increased risk of small-for-gestational-age infants. LSG decreases the risk of gestational diabetes mellitus independent of the time interval between surgery and conception.