title: Maternal obesity (Class I-III), gestational weight gain and maternal leptin levels during and after pregnancy: a prospective cohort study.
abstract: BACKGROUND
  Maternal obesity is accompanied by maternal and fetal complications during and after pregnancy. The risks seem to increase with degree of obesity. Leptin has been suggested to play a role in the development of obesity related complications. Whether maternal leptin levels differ between obese and morbidly obese women, during and after pregnancy, have to our knowledge not been previously described. Neither has the association between maternal leptin levels and gestational weight gain in obese women. The aim was to evaluate if maternal plasma leptin levels were associated with different degrees of maternal obesity and gestational weight gain.
  
  
  METHODS
  Prospective cohort study including women categorized as obesity class I-III (n = 343) and divided into three gestational weight gain groups (n = 304). Maternal plasma leptin was measured at gestational week 15, 29 and 10 weeks postpartum. Maternal Body Mass Index (BMI) was calculated from early pregnancy weight. Gestational weight gain was calculated using maternal weight in delivery week minus early pregnancy weight. The mean value and confidence interval of plasma-leptin were analysed with a two-way ANOVA model. Interaction effect between BMI and gestational weight gain group was tested with a two-way ANOVA model.
  
  
  RESULTS
  The mean maternal leptin concentrations were significantly higher in women with obesity class III compared to women in obesity class I, at all times when plasma leptin were measured. The mean leptin concentrations were also significantly higher in women with obesity class II compared to women in obesity class I, except in gestational week 29. There was no difference in mean levels of plasma leptin between the gestational weight gain groups. No significant interaction between BMI and gestational weight gain group was found.
  
  
  CONCLUSIONS
  Plasma leptin levels during and after pregnancy were associated with obesity class but not with degree of gestational weight gain. These results are in concordance with epidemiological findings where the risk of obstetric complications increases with increased maternal obesity class. The effect on obstetric outcome by degree of gestational weight gain is less pronounced than the adverse effects associated with maternal obesity.
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Carlhäll
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Bladh
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Brynhildsen
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Ing-Marie
authors.initials: IM
authors.lastname: Claesson
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Josefsson
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Sydsjö
authors.affiliation: Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, 58185 Linköping, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Thorsell
authors.affiliation: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Blomberg
keywords: Gestational weight gain; Leptin; Maternal obesity; Pregnancy and body mass index