title: Maternal and neonatal outcomes in obese women who lose weight during pregnancy.
abstract: OBJECTIVE
  To evaluate neonatal and maternal outcomes in obese pregnant women whose weight gain differed from the Institute of Medicine (IOM) recommendations.
  
  
  METHODS
  Maternal and neonatal outcomes associated with weight change in pregnancy were retrospectively investigated in women with obesity (body mass index (BMI) ⩾30 kg m(-2); N=10734) who gave birth at 12 hospitals. Using a 1:1:1:1 design (n=778 matched groups), we matched women with obesity who lost, maintained, gained appropriate (IOM recommended) and gained excessive weight during pregnancy by gestational age at delivery, maternal age, race/ethnicity, prepregnancy BMI, chronic hypertension, pregestational diabetes and smoking status. Regression techniques were used to adjust for confounders and compare outcomes across weight change categories.
  
  
  RESULTS
  Compared with IOM recommendations, weight loss was associated with twofold greater odds of low birth weight infants and a mean decrease in estimated blood loss of 30 ml; excessive weight gain was associated with doubled odds of gestational hypertension or preeclampsia, fourfold greater odds of macrosomia and a mean decrease in 5-min APGAR of 0.09. From lost to excessively gained weight, the odds of cesarean delivery increased 1.4 times and mean infant birth weight increased by 197 g. In contrast, the odds of small-for-gestational age were 1.8 times greater for women who lost than gained excessive weight.
  
  
  CONCLUSIONS
  Weight loss in obese pregnant women is associated with increased risk for low birth weight neonates but significantly decreased or maintained risk for other maternal and neonatal morbidities, as compared with appropriate or excessive weight gain. This study supports re-evaluation of the current IOM guidelines for women with obesity.
authors.affiliation: Department of Obstetrics and Gynecology, Aurora Health Center, Milwaukee, WI, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Cox Bauer
authors.affiliation: Aurora Health Care, Milwaukee, WI, USA.|Center for Urban Population Health, Milwaukee, WI, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Bernhard
authors.affiliation: Aurora Health Care, Milwaukee, WI, USA.|Center for Urban Population Health, Milwaukee, WI, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Greer
authors.affiliation: Department of Obstetrics and Gynecology, Aurora Health Center, Milwaukee, WI, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Merrill
mesh_terms: D000328:Adult; D002585:Cesarean Section; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D007230:Infant, Low Birth Weight; D007236:Infant, Small for Gestational Age; D009765:Obesity / Q000503:physiopathology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D012307:Risk Factors; D015430:Weight Gain; D015431:Weight Loss