BACKGROUND AND PURPOSE:

• The ARRIVE trial (published in 2018) found that elective induction at 39 weeks’ gestation led to fewer cesarean deliveries and lower incidence of adverse pregnancy outcomes
• Gilroy et al. (AJOG, 2022) assessed whether there were changes in obstetric practices and perinatal outcomes in the US after the ARRIVE trial publication

METHODS:

• Population based, retrospective cohort study
  • Data derived from National Vital Statistics System (NVSS) database
• Population
  • Low-risk nulliparous women who initiated prenatal care by 12 weeks’ gestation with singleton, non-anomalous pregnancies that delivered at ≥ 39 weeks
• Exposures
  • Pre-ARRIVE: Delivery between January 2015 and December 2017
  • Post-ARRIVE: Delivery between January 2019 and December 2019
• Study design
  • Univariate and multivariate analyses were performed
  • Trends were tested across the time period represented by the pre-ARRIVE group
  • Adjustment was performed for differences (P<0.001 between exposure groups) for age, race, BMI, marital status, infertility treatment and smoking history
• Primary outcomes
  • Practice outcomes
    • Rate of induction of labor
    • Timing of delivery
    • Cesarean rate
  • Maternal outcomes
    • Blood transfusion
    • ICU admission
  • Neonatal outcomes
    • Need for assisted-ventilation (immediate and >6 hours)
    • 5-minute APGAR score <3
    • NICU admission
    • Seizures
    • Surfactant use

RESULTS:

• Pre-ARRIVE: 1,966,870 births | Post-ARRIVE: 609,322 births

Practice outcomes

• The post-ARRIVE group was more likely to
  • Undergo induction
    • Pre: 30.2% | Post: 36.1%
    • aOR 1.39 (95% CI, 1.36 to 1.37)
  • Delivery by 39w6d weeks of pregnancy
    • Pre: 39.9% | Post: 42.8%
    • aOR 1.14 (95% CI, 1.14 to 1.15)
• The post-ARRIVE group had a significantly lower rate of cesarean delivery
  • Pre: 27.9% | Post: 27.3%
  • aOR 0.94 (95% CI, 0.93 to 0.94)

Maternal outcomes

• Patients in the post-ARRIVE group were more likely to
  • Receive a blood transfusion
    • Pre: 0.3% | Post: 0.4%
    • aOR 1.43 (95% CI 1.36 to 1.50)
  • Be admitted to the MICU
    • Pre: 0.08% | Post: 0.09%
    • aOR 1.20 (95% CI, 1.09 to 1.33)

Neonatal outcomes

• Neonates in the post-ARRIVE group were more likely to
  • Need assisted ventilation at birth
    • Pre: 2.8% | Post: 3.5%
    • aOR 1.28 (95% CI, 1.26 to 1.30)
  • Need assisted ventilation at >6 hours
    • Pre: 0.5% | Post: 0.6%
    • aOR 1.36 (95% CI, 1.31 to 1.41)
  • Have low 5-min APGAR
    • Pre: 0.3% | Post: 0.4%
    • aOR 0.91 (95% CI, 0.86 to 0.95)
• There was no difference in
  • NICU admission
    • Pre: 4.9% | Post: 4.9%
    • aOR 1.01 (95% CI, 0.99 to 1.03)
  • Neonatal seizures
    • Pre: 0.04% | Post: 0.04%
    • aOR 0.97 (95% CI, 0.84 to 1.13)

CONCLUSION:

• Following the ARRIVE trial publication, there were more inductions, more deliveries at 39 weeks, and fewer cesarean deliveries 
• Some adverse neonatal and maternal outcomes were increased following ARRIVE trial publication
• Limitations include the extent of data that is available within the NVSS and birth certificates           
• The authors state

There was a significant decrease in the rate of cesarean deliveries in 2019 after the publication of the ARRIVE trial…

There were also increased rates of MICU admissions and low 5-minute APGAR scores (albeit still within the range of the rates seen over the 3 years in the pre-ARRIVE group) in the post-ARRIVE group

Although the changes in adverse perinatal outcomes were small, their potential clinical implications warrant further inquiry

Learn More – Primary Sources:

Changes in obstetric practices and pregnancy outcomes following the ARRIVE trial

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