For a baby born in the U.S., the likelihood of entering the world through the birth canal or by cesarean section is not based strictly on clinical factors. Insurance coverage and the hospital where that baby is delivered also play a role.
Last year, about a fifth of all babies born at DMC Harper-Hutzel hospitals in Detroit were delivered by C-section. At two nearby hospitals, Henry Ford West Bloomfield Hospital and McLaren Macomb in Mount Clemens, Mich., a quarter and well over one-third of the babies were, respectively.
The rate of babies born by C-section varied by 15.3 percentage points across the three hospitals, according to data they submitted to the Leapfrog Group, an employer-backed quality and patient-safety group in Washington, D.C.
But the numbers don't explain why a higher proportion of babies were born by C-section at McLaren Macomb than at Harper-Hutzel.
Figuring out those drivers can lower the nation's high C-section rate and related healthcare spending. But there's a dearth of information about how delivery decisions are made at each hospital.
“One of the things we don't know a lot about in maternity care is hospital management practices,” said Katy Kozhimannil, an associate professor at the University of Minnesota School of Public Health. “Obstetrics is not the most lucrative service line for healthcare delivery systems, so it's not the place where most attention goes.”
High and wildly varying rates of C-sections across the U.S.—and the reasons for both—are well-established. Insurers pay more for C-sections than vaginal births, which take more time in hospitals that are often pressed for space.
Doctors also fear malpractice suits stemming from natural births, even though C-sections are considered riskier than vaginal births unless medically necessary. Accounting for nearly one-third of births in 2014, C-sections in the U.S. are performed at double the rate the World Health Organization considers medically necessary.
The average rate of C-sections among women considered less likely to need the procedure—first-time mothers with a single baby at term and positioned head-down—was 25.8% among hospitals that reported to Leapfrog in 2016. That C-section rate fell less than 1 percentage point from the year before, when the average rate was 26.4%. Meanwhile, rates varied wildly by state, from 17.1% in New Mexico to 32.1% in Louisiana.