RESUMEN
OBJECTIVES: To describe the population of women having bariatric surgery and compare the pregnancy outcomes for women having bariatric surgery with a non-bariatric surgery population having a first and second pregnancy. DESIGN: Population-based record linkage study. SETTING: New South Wales (NSW), Australia. POPULATION: All women aged 15-45 years with a hospital record in NSW (2002-2014) and all women giving birth in NSW (1994-2015; n = 1 606 737 women). METHODS: Pregnancy and birth outcomes were compared between first and second pregnancies using repeated-measures logistic regression and paired Student's t-tests. Bariatric and non-bariatric groups were also compared. MAIN OUTCOME MEASURES: Maternal diabetes, preterm birth (<37 weeks of gestation) and large for gestational age. RESULTS: There was a 13-fold increase in hospitalisations for primary bariatric surgery during 2002-2014. Compared with the general birthing population, women who had bariatric surgery experienced higher rates of hypertension, diabetes, and preterm birth. Among women who had bariatric surgery between a first and second pregnancy, there were reduced rates of hypertension (OR 0.39, 95% CI 0.29-0.53), spontaneous preterm birth (OR 0.37, 95% CI 0.16-0.86), infants that were large for gestational age (OR 0.63, 95% CI 0.44-0.88), and the admission of infants to a special care nursery or neonatal intensive care (OR 0.64, 95% CI 0.46-0.90) in the second pregnancy. Rates for small-for-gestational age and gestational diabetes following surgery were 8.3 and 11.4%, respectively CONCLUSIONS: Bariatric surgery between a first and second pregnancy was associated with reductions in obesity-related adverse pregnancy outcomes. Bariatric surgery performed for the management of obesity in accordance with current clinical criteria is associated with improved pregnancy outcomes in a subsequent pregnancy. TWEETABLE ABSTRACT: Bariatric surgery for obesity may improve pregnancy and birth outcomes in a subsequent pregnancy.