Although clinically indicated cesarean deliveries may improve outcomes for mothers and infants, “when not clinically indicated, cesarean delivery is a major surgical intervention that increases risk for adverse outcomes,” wrote Anna M. Frappaolo of Columbia University College of Physicians and Surgeons, New York, and colleagues.
The Healthy People 2030 campaign includes the reduction of cesarean deliveries, but trends in these procedures, especially with regard to diagnoses of labor arrest, have not been well studied, the researchers said.
In an analysis published in JAMA Network Open, the researchers reviewed delivery hospitalizations using data from the National Inpatient Sample from 2000 to 2019.
Births deemed low risk for cesarean delivery were identified by using criteria of the Society for Maternal-Fetal Medicine and additional criteria, and joinpoint regression analysis was used to estimate changes.
The researchers examined overall trends in cesarean deliveries as well as trends for three specific diagnoses: nonreassuring fetal status, labor arrest, and obstructed labor.
The final analysis included 40,517,867 deliveries; of these, 4,885,716 (12.1%) were cesarean deliveries.
Overall, cesarean deliveries in patients deemed at low risk increased from 9.7% in 2000 to 13.9% in 2009, then plateaued and decreased from 13.0% in 2012 to 11.1% in 2019. The average annual percentage change (AAPC) for cesarean delivery was 6.4% for the years from 2000 to 2005, 1.2% from 2005 to 2009, and −2.2% from 2009 to 2019.
Cesarean delivery for nonreassuring fetal status increased over the entire study period, from 3.4% in 2000 to 5.1% in 2019. By contrast, overall cesarean delivery for labor arrest increased from 3.6% in 2000 to a high of 4.8% in 2009, then decreased to 2.7% in 2019. Cesarean deliveries with a diagnosis of obstructed labor decreased from 0.9% in 2008 to 0.3% in 2019.
More specifically, cesarean deliveries for labor arrest in the active phase, latent phase, and second stage of labor increased from 1.5% to 2.1%, 1.1% to 1.5%, and 0.9% to 1.3%, respectively, from 2000 to 2009, and decreased from 2.1% to 1.7% for the active phase, from 1.5% to 1.2% for the latent phase, and from 1.2% to 0.9% for the second stage between 2010 and 2019.
Patients with increased odds of cesarean delivery were older (aged 35-39 years vs. 25-29 years, adjusted odds ratio 1.27), delivered in a hospital in the South vs. the Northeast of the United States (aOR 1.11), and were more likely to be non-Hispanic Black vs. non-Hispanic White (OR 1.23).
Notably, changes in nomenclature and interpretation of intrapartum electronic fetal heart monitoring occurred during the study period, with recommendations for the adoption of a three-tiered system for fetal heart rate patterns in 2008. “It is possible that current evidence and nomenclature related to intrapartum FHR interpretation may result in identification of a larger number of fetuses deemed at indeterminate risk for abnormal acid-base status,” the researchers wrote in their discussion.
The study findings were limited by several factors including the use of administrative discharge data rather than clinical records, the exclusion of patients with chronic conditions associated with cesarean delivery, changes in billing codes during the study period, and the inability to account for the effect of health factors, maternal age, and use of assisted reproductive technology, the researchers noted.
However, the results were strengthened by the large sample size and 20-year study period, as well as the stratification of labor arrest by stage, and suggest uptake of newer recommendations, they said. “Future reductions in cesarean deliveries among patients at low risk for cesarean delivery may be dependent on improved assessment of intrapartum fetal status,” they concluded.