At the 11 hospitals in the study, as the number of obstetricians per unit increased, the rate of cesareans, or C-sections, performed after labor had begun decreased, said study leader Saad Zbiri. And as the number of midwives per unit increased, fewer cesareans were done that had been planned in advance.
C-section rates have been rising in the developed world in recent years even though the World Health Organization recommends this surgery only for the approximately 10 to 15 percent of births when the health of the mother or baby is in danger.
Decreases in maternity unit staffing have contributed to this trend, Zbiri said by email.
“We showed that the woman’s probability of having a cesarean is affected by the staffing levels of the hospital where she delivers,” Zbiri added.
Zbiri and colleagues examined data on more than 102,000 deliveries between 2008 and 2014. Overall, about 24 percent were cesarean deliveries.
On average, for every 200 deliveries, hospitals in the study had about one obstetrician, three midwives, and one anesthesiologist on staff, the researchers reported in PLOS One journal.
The number of anesthesiologists on staff didn’t appear to influence the potential for C-section deliveries, the study found.
But researchers calculated that a 10 percent increase in the number of full-time obstetricians was associated with a 2.5 percentage point drop in rates of C-sections done after women went into labor, from 13.1 percent to 10.6 percent.
And a 10 percent increase in the number of full-time midwives was associated with a 3.4 percentage point decline in elective C-sections, from 10.3 percent to 6.9 percent.
The study wasn’t designed to prove whether or how staffing levels might directly impact C-section rates, and it also wasn’t designed to determine if lower C-section rates might improve health outcomes for mothers or babies.
“One of the concerns when there are provider shortages is the ability to care for everyone should an emergency arise,” said Erin Wright, a researcher at the Johns Hopkins University School of Nursing in Baltimore who wasn’t involved in the study.
“Although the article does not infer this as causation, it is theoretically possible that providers may be more quick to decide upon a cesarean delivery for a non-urgent patient if they have other patients to care for,” Wright said by email.
While C-sections may be necessary when the lives of mothers or babies are at risk, the surgery carries a risk of infection, excessive bleeding, damage to reproductive organs, and blood clots, said Saraswathi Vedam, a researcher at the University of British Columbia in Vancouver, Canada, who wasn’t involved in the study.
“Surgical deliveries can also lead to delays in breastfeeding and mother-baby bonding as well as an increased risk of asthma and obesity for babies,” Vedam said by email.
“Cesareans can improve overall population health only when they are utilized to balance known or projected risks that exist due to real medical conditions like maternal hypertension which could be cured by early delivery, as opposed to (when they are used to) respond to time or staffing constraints,” Vedam added.