title: Maternal prepregnancy overweight and obesity and the pattern of labor progression in term nulliparous women.
abstract: OBJECTIVE
  To examine the effect of maternal overweight and obesity on labor progression.
  
  
  METHODS
  We analyzed data from 612 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. The median duration of labor by each centimeter of cervical dilation was computed for normal-weight (body mass index [BMI] 19.8-26.0 kg/m2), overweight (BMI 26.1-29.0 kg/m2), and obese (BMI > 29.0 kg/m2) women and used as a measurement of labor progression.
  
  
  RESULTS
  After adjusting for maternal height, labor induction, membrane rupture, oxytocin use, epidural analgesia, net maternal weight gain, and fetal size, the median duration of labor from 4 to 10 cm was significantly longer for both overweight and obese women, compared with normal-weight women (7.5, 7.9, and 6.2 hours, respectively). For overweight women, the prolongation was concentrated around 4-6 cm, whereas for obese women, their labor was significantly slower before 7 cm.
  
  
  CONCLUSIONS
  Labor progression in overweight and obese women was significantly slower than that of normal-weight women before 6 cm of cervical dilation. Given that nearly one half of women of childbearing age are either overweight or obese, it is critical to consider differences in labor progression by maternal prepregnancy BMI before additional interventions are performed.
authors.affiliation: Department of Maternal and Child Health, School of Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. amv@med.umich.edu
authors.forename: Anjel
authors.initials: A
authors.lastname: Vahratian
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: James F
authors.initials: JF
authors.lastname: Troendle
authors.forename: David A
authors.initials: DA
authors.lastname: Savitz
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Siega-Riz
mesh_terms: D015992:Body Mass Index; D001835:Body Weight; D002584:Cervix Uteri / Q000503:physiopathology; D002585:Cesarean Section; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000502:physiology*; D009765:Obesity / Q000503:physiopathology*; D011247:Pregnancy