Planned cesarean deliveries rare, appear to be safe for low-risk pregnancies

Women with low-risk pregnancies in Ontario who requested a cesarean delivery had a reduced risk for short-term adverse delivery outcomes vs. those who planned a vaginal delivery, according to a recent cohort study.

The results also showed that cesarean delivery on maternal request (CDMR) rates in Ontario remained unchanged from 2012 to 2018.

“Our finding that CDMR rates have remained stable in Ontario provides reassurance to those concerned about the potential contribution of CDMR to rising cesarean delivery rates,” Darine El-Chaâr, MD, FRCSC, Msc, of the department of obstetrics, gynecology and newborn care at the Ottawa Hospital in Ontario, and colleagues wrote.

Similarly, other data presented during the virtual American College of Obstetricians and Gynecologists Annual Clinical and Scientific Meeting showed that CDMR rates in the United States have only slightly increased since 1999 and remain low.

Delivery outcomes

El-Chaâr and colleagues conducted a population-based retrospective cohort study among 422,210 women (mean maternal age, 29.7 years; white, 39.4%) in Ontario who had a low-risk pregnancy between April 2012 and March 2018.

Among the study population, 46,533 women had a cesarean delivery, of which 3.9% (n = 1,827) were planned. Compared with women who had a planned vaginal delivery, those who had a planned cesarean delivery had a lower adjusted risk for adverse outcomes (adjusted RR [aRR] = 0.42; 95% CI, 0.33-0.53) and lower Weighted Adverse Outcome Score (mean difference = –1.28; 95% CI, –2.02 to –0.55).

“This analysis shows that planned CDMR is safe for low-risk pregnancies and may be associated with a lower risk of adverse delivery outcomes compared with planned vaginal deliveries,” El-Chaâr and colleagues wrote. “Although our study addresses concerns related to the immediate implications of planned CDMR, exploration of longer-term risks is needed, including its impact on breastfeeding, and the child’s risk for infection and respiratory illness.”

CDMR rates

Among all cesarean deliveries in the study, the proportion of women who had one by request remained at 3.9% over the 6-year study period (2012-2018), according to El-Chaâr and colleagues.

In another study that focused on CDMR rates in the U.S., Marie-Julie Trahan, MD, of the department of obstetrics and gynecology at McGill University, and colleagues analyzed data from The Healthcare Cost and Utilization Project-Nationwide Inpatient Sample. The data were gathered from 1999 to 2015.

The researchers identified 228,586 patients (53.49% white) who had an elective cesarean section without fetal or maternal indications among a total of 13,698,835 deliveries (53.08% white).

Although Trahan and colleagues reported that “the rate of cesarean delivery has increased in the United States over the last several decades,” they found that the rates of CDMR “have increased only slightly since 1999.” According to the researchers, CDMR accounted for 1% to 2.04% of all live births and 4.64% to 6.09% of all cesarean deliveries during the study period.

Factors associated with CDMR

There were several commonalities between Canadian and U.S. women who requested a cesarean delivery, including income and age. In the U.S. study sample, women who had a CDMR were more likely to be aged over 35 years, be in the highest income quartile and have private insurance. Trahan and colleagues wrote that these findings “may indicate that the option of CDMR is more appealing or more frequently offered to a certain population of patients.”

In the Canadian sample, women were more likely to be older, have higher levels of education, conceive via in vitro fertilization, have anxiety, nulliparity, be white and deliver at a hospital that provided higher levels of maternal and obstetrician-based antenatal care.

“The role of care providers in facilitating or influencing a woman’s preferred mode of delivery ... warrants examination. Although care providers are supportive of a woman’s right to choose CDMR, surveys show variable willingness to comply with such requests,” El-Chaâr and colleagues wrote. “In our study, care from an obstetrician was a significant determinant of CDMR, suggesting that women who plan CDMR are more likely to seek out care from an obstetrician and that women preferring vaginal deliveries are more likely to seek antenatal care from a midwife.”

References:

• Canadian Medical Association Journal. Planned cesarean births safe for low-risk pregnancies. Available at: https://www.eurekalert.org/pub_releases/2021-05/cmaj-pcb042821.php. Accessed May 5, 2021.
• Guo Y, et al. CMAJ. 2021;doi:10.1503/cmaj.202262.
• Trahan MJ, et al. Cesarean Delivery on Maternal Request in the United States from 1999 to 2015. Presented at: Presented at: American College of Obstetricians and Gynecologists Annual Clinical and Scientific Meeting; April 30-May 4, 2021 (virtual meeting).