Bariatric surgery in a national cohort of women: sociodemographics and obstetric outcomes.

OBJECTIVE In a large, prospective Swedish national cohort, we investigated individual birth characteristics for women who had undergone bariatric surgery and their obstetric outcome and made comparisons with all other women during the same period. STUDY DESIGN The cohort consisted of 494,692 women born 1973-1983 of which 681 women who had undergone bariatric surgery constituted the index group. RESULTS The index women more often have parents with lower sociodemographic status and are more often born large for gestational age. The women surgically treated before their first child had a shorter gestational length, their children had lower birthweight, and were more often born small for gestational age compared with the children born to the reference mothers. Women whose child was born before their bariatric surgery more often had a cesarean section, and their children were more often large for gestational age. CONCLUSION Preconception bariatric surgery in obese women may be associated with improved obstetric outcomes.