BACKGROUND AND PURPOSE:

• There is limited research on midwifery care in hospital settings
• Souter et al., (Obstetrics and Gynecology, 2019) sought to determine if there are differences between perinatal outcomes as well as intervention rates when comparing midwife vs ObGyn care in a low-risk hospital setting

METHODS:

• Study design
  • Multi-centered retrospective cohort study (2014 to 2018)
• Participants
  • Singleton births |37w0d to 42w6d
• Data collection
  • Interventions: Induction | AROM | Epidural | Oxytocin | Episiotomy
  • Mode of delivery
  • Maternal outcomes: 3^rd and 4^th degree tears | PPH | transfusion | Severe Maternal morbidity
  • Newborn outcomes: Shoulder dystocia | 5-minute Apgar score | Resuscitation at delivery | Birth trauma | NICU admission
• Data analysis: Regression models to adjust for confounding
  • Data stratified by parity (nulliparity vs multiparity)
  • Confounders: Maternal age | BMI | Height | Race | IOL  | Epidural | Hospital Practitioner

RESULTS:

• 23,100 births
  • 3,816 midwife deliveries | 19,284 ObGyn deliveries
• Except for oxytocin induction use, where there was no difference, intervention rates were lower among midwifery cohort
• For nulliparous women, the following were less likely to be associated with midwifery care  
  • IOL
    • Midwife: 14.7%
    • ObGyn: 20.4%
    • Relative Risk (RR) 0.72 (95% CI, 0.64 to 0.81)
  • Episiotomy
    • Midwife: 3.8%
    • ObGyn: 6.7%
    • RR 0.57 (95% CI, 0.43 to 0.74)
• In nulliparous women, birth at ≥41w0d more likely in midwifery group
  • Midwife: 25.3%
  • ObGyn: 20.6%
  • RR 1.23 (95%, CI, 1.12 to 1.34)
• Mode of delivery:  Lower risk of cesarean delivery in the midwifery group
  • Nulliparous: Adjusted RR 0.68 (95% CI, 0.57 to 0.82)
  • Multiparous: Adjusted RR 0.57 (95% CI, 0.36 to 0.89)
• Operative vaginal birth: Lower risk in the midwifery group  
  • Nulliparous: Adjusted RR 0.73 (95% CI, 0.57 to 0.93)
  • Multiparous: Adjusted RR 0.30 (95% CI, 0.14 to 0.63)
• Neonatal outcomes: Shoulder dystocia was more common in midwifery group for multiparous patients
  • Midwife: 5.1%
  • ObGyn: 3.1%
  • Adjusted RR 1.42 (95% CI, 1.04 to 1.92)

CONCLUSION:

• Results from this study demonstrated increased interventions, cesarean and operative vaginal birth rates among women delivered by an obstetrician vs a midwife in a low-risk hospital setting
• There was a 40% increased risk for shoulder dystocia among multiparous women delivered by a midwife
• Limitations of this study acknowledged by the authors include
  • Retrospective observational design (association and not causation)
    • Patients selecting midwifery care may be self-selected and strongly desire vaginal delivery
  • Adverse outcomes: Aside from shoulder dystocia, the authors state that there were “No statistically significant differences were observed in any of the other maternal or newborn outcomes; however, multiple outcomes were underpowered to assess statistical differences”
  • Intrapartum management
    • The study could track midwifery patients delivered by an ObGyn but could not track (1) intrapartum consultations; (2) when the ObGyn became involved (3) indications for the involvement in care
• The authors state in their conclusion that “Larger studies would be needed to more fully evaluate midwifery care in the United States.”  

Learn More – Primary Sources:

Comparison of Midwifery and Obstetric Care in Low-Risk Hospital Births

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