title: The impact of obesity on outcomes of midwife-led pregnancy and childbirth in a primary care population: a prospective cohort study.
abstract: OBJECTIVE
  To assess the impact of obesity on the likelihood of remaining in midwife-led care throughout pregnancy and childbirth.
  
  
  METHODS
  Secondary analysis of data from a prospective cohort study.
  
  
  METHODS
  Dutch midwife-led practices.
  
  
  METHODS
  A cohort of 1369 women eligible for midwife-led care after their first antenatal visit.
  
  
  METHODS
  First-trimester body mass index (BMI) was calculated as weight measured at booking divided by height squared. Obstetric data were retrieved from medical records. Multiple logistic regressions were performed to examine the effects of BMI classification on midwife-led pregnancies and childbirths.
  
  
  METHODS
  Percentages of women remaining in midwife-led care throughout pregnancy and throughout childbirth.
  
  
  RESULTS
  Of women in obesity classes II and III, 55% remained in midwife-led care throughout pregnancy and 30% remained in midwife-led care throughout birth. Compared with women of normal weight, women in obesity classes II and III had fewer midwife-led pregnancies (OR 0.38, 95% CI 0.21-0.69), and women who were overweight or in obesity class I had fewer midwife-led childbirths (OR 0.63, 95% CI 0.44-0.90; OR 0.49, 95% CI 0.29-0.84, respectively). Compared with women of normal weight, women who were obese had higher referral rates for hypertensive disorders (4 versus 14%), prolonged labour (4.6 versus 10.4%), and intrapartum pain relief (4 versus 10.4%). The women who were eligible for midwife-led birth and who were overweight or obese, had no more urgent referrals than women of normal weight. Women who were obese and who completed a midwife-led birth had no more adverse outcomes than women of normal weight, with the exception of higher rates of large for gestational age (LGA) babies (>97.7 centile; 12.1%, versus 1.9% in normal weight and versus 3.3% in overweight women).
  
  
  CONCLUSIONS
  Although fewer women who were obese remain in midwife-led care during pregnancy and childbirth, there was no increased risk of unfavourable birth outcomes for women who were obese and eligible for a midwife-led birth when compared with women of normal weight. This indicates that when primary care midwives use a risk assessment tool throughout pregnancy and childbirth they are able to safely assign women who are obese to either midwife-led or obstetrician-led care.
authors.affiliation: Faculty of Midwifery Education and Studies Maastricht, Research Centre for Midwifery Science, Zuyd University, Maastricht, the Netherlands.
authors.forename: D O A
authors.initials: DO
authors.lastname: Daemers
authors.forename: H A A
authors.initials: HA
authors.lastname: Wijnen
authors.forename: E B M
authors.initials: EB
authors.lastname: van Limbeek
authors.forename: L M
authors.initials: LM
authors.lastname: Budé
authors.forename: M J
authors.initials: MJ
authors.lastname: Nieuwenhuijze
authors.forename: M E A
authors.initials: ME
authors.lastname: Spaanderman
authors.forename: R G
authors.initials: RG
authors.lastname: de Vries
mesh_terms: D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D005320:Fetal Macrosomia / Q000453:epidemiology* / Q000451:nursing; D006801:Humans; D007231:Infant, Newborn; D008880:Midwifery / Q000379:methods; D009035:Mothers; D009426:Netherlands / Q000453:epidemiology; D009765:Obesity / Q000150:complications* / Q000453:epidemiology / Q000451:nursing; D016017:Odds Ratio; D010298:Parity; D018743:Perinatal Care; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000209:etiology* / Q000451:nursing; D011256:Pregnancy Outcome; D011320:Primary Health Care; D011446:Prospective Studies; D012017:Referral and Consultation / Q000706:statistics & numerical data; D018570:Risk Assessment; D012307:Risk Factors; D015430:Weight Gain
keywords: Birth outcome; childbirth; midwife-led; obesity; pregnancy; primary care; risk assessment