Cesarean Delivery Trends Among Patients at Low Risk for Cesarean Delivery in the US, 2000-2019

Abstract

ImportanceReducing rates of unnecessary cesarean deliveries is both a national and a global health objective. However, there are limited national US data on trends in indications for low-risk cesarean delivery.ObjectiveTo determine temporal trends in and indications for cesarean delivery among patients at low risk for the procedure over a 20-year period.Design, Setting, and ParticipantsThis cross-sectional study analyzed 2000 to 2019 delivery hospitalizations using the National Inpatient Sample. Births at low risk for cesarean delivery were identified using a definition from the Society for Maternal-Fetal Medicine and additional criteria. Temporal trends in cesarean birth were analyzed using joinpoint regression to estimate the average annual percentage change (AAPC) with 95% CIs. Data analysis was performed from August 2022 to January 2023.ExposureThis analysis evaluated cesarean birth trends in a population at low risk for this procedure over a 20-year period.Main Outcomes and MeasuresIn addition to overall cesarean birth risk, cesarean deliveries for nonreassuring fetal status and labor arrest were individually analyzed.ResultsOf an estimated 76.7 million delivery hospitalizations, 21.5 million were excluded according to the Society for Maternal-Fetal Medicine definition, and 14.7 million were excluded according to additional criteria. Of the estimated 40 517 867 deliveries included, 12.1% (4 885 716 deliveries) were by cesarean delivery. Cesarean deliveries among patients at low risk for the procedure increased from 9.7% to 13.9% between 2000 and 2009, plateaued, and then decreased from 13.0% to 11.1% between 2012 and 2019. The AAPC for cesarean delivery was 6.4% (95% CI, 5.2% to 7.6%) from 2000 to 2005, 1.2% from 2005 to 2009 (95% CI, −1.2% to 3.7%), and −2.2% from 2009 to 2019 (95% CI, −2.7% to −1.8%). Cesarean delivery for nonreassuring fetal status increased from 3.4% of all deliveries in 2000 to 5.1% in 2019 (AAPC, 2.1%; 95% CI, 1.7% to 2.5%). Cesarean delivery for labor arrest increased from 3.6% in 2000 to a peak of 4.8% in 2009 before decreasing to 2.7% in 2019. Cesarean deliveries for labor arrest increased during the first half of the study (2000-2009) for the active phase (from 1.5% to 2.1%), latent phase (from 1.1% to 1.5%), and second stage (from 0.9% to 1.3%) and then decreased from 2010 to 2019, 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.Conclusions and RelevanceCesarean deliveries among patients at low risk for cesarean birth appeared to decrease over the latter years of the study period, with cesarean deliveries for labor arrest becoming less common.

Cesarean Delivery Uptake Trends Associated With Patient Features and Threshold for Labor Anomalies

“…Increased rates of abnormal intrapartum fetal monitoring can be expected owing to prolongation of labor, particularly the second stage, justifying both the finding of increased risk of cesarean delivery for nonreassuring fetal status and lower rate of labor arrest in the second phase of the study by Frappaolo and colleauges. 1 On the maternal side, the benefits of prolonged labor on the reduction of cesarean delivery rates should be cautiously weighed against long-term risks of obstetric anal sphincter injury and pelvic floor dysfunctions, as well as uterine atony and postpartum hemorrhage.…”

“…delivery rates across the study period showed a decrease, with a change in the frequency of the various indications for cesarean delivery over time, with decreasing rates of labor arrest widely exceeding the increasing rates of nonreassuring fetal status. 1 The authors note that the use of administrative data is a major limitation of their study, because it includes the risks of diagnostic discrepancy with clinical files and a lack of standardization of intrapartum diagnoses among different centers, both of which are challenging in similar studies and represent nonnegligible sources of bias and heterogeneity. However, these limitations do not hinder the extensive merit and importance of the present study.…”

“…However, these limitations do not hinder the extensive merit and importance of the present study. 1 Frappaolo et al 1 used the Society for Maternal-Fetal Medicine's criteria for low risk of cesarean delivery, which include full-term, singleton, vertex live births with no prior cesarean delivery and without specific high-risk diagnoses. 2 This definition is more comprehensive and advantageous than others but still presents a few limitations in that it cannot assess the cumulative effect of numerous risk factors (that independently may not be sufficient to define high risk) and it cannot include all clinical conditions that increase the risk of cesarean delivery.…”

“…In fact, the authors found a progressively increasing odds ratio for cesarean delivery with advancing maternal age (from 1.07 at 30-34 years to 1.30 at 35-39 years) vs the reference category (25-29 years). 1 This knowledge should be reconciled with the definition of risk by reassessing criteria for low-risk patients, including mode of conception with homologous or heterologous in vitro fertilization (IVF), assessment of uterine and pelvic anatomy, maternal chronic morbidities, fetal abnormalities, and abnormal fetal growth (both reduced and increased). In recent decades in most developed countries, the use of IVF has increased greatly, with particular interest in oocyte donations for patients of advanced age.…”

“…4 The definition of labor dystocia was recently reviewed by the Society for Maternal-Fetal Medicine after demonstration that labor progresses at a rate substantially slower than what was traditionally taught. Consequently, during the second half of the study by Frappaolo and colleauges, 1 longer standards for labor duration were allowed by individual clinicians, according to these indications. However, longer labor duration may increase maternal and fetal risks.…”