Studies of women with a body mass index over 30/kg/m² who had received laparoscopic adjustable gastric band surgery and reported data on maternal and neonatal outcomes were eligible for inclusion. The results of case reports were excluded.
The included studies were published from 2001 up to 2011. The mean pre-pregnancy body mass index ranged from 30.3kg/m² to 41.7kg/m² (where reported). The intervals from the gastric band surgery to conception ranged from 17 months to 12 years. Balloon management included active management of the band to prevent first trimester nausea and vomiting, deflation of the band in cases of poor nutrition or frequent vomiting, or emptying only in the event of hyperemesis. The control groups in most of the studies were obese women who had not undergone laparoscopic adjustable gastric band surgery; there were also overweight women no longer classified as morbidly obese (body mass index 29.9kg/m² ±3.5) and normal weight women (body mass index 22.2kg/m² ±1.4).
The reported maternal outcomes included band-related complications or adjustments, gestational weight gain, gestational diabetes, pregnancy-induced hypertension, pre-eclampsia, and caesarean section delivery rates. Neonatal outcomes included preterm delivery (prior to 37 weeks gestation), low birth weight (less than 2,500g), high birth weight (over 4,000g), large for gestational age, small for gestational age, spontaneous abortion, congenital abnormalities, and admissions to neonatal intensive care units.
The authors did not state how many reviewers performed the study selection.