Researchers at the U of M’s School of Public Health analyzed hospital discharge data from 593 hospitals that had at least 100 births in 2009. They found that the C-section rate ranged from 7.1 percent to 69.9 percent.
Hospital C-section rates could, of course, be expected to vary somewhat, as some hospitals serve populations with a greater number of women at risk for pregnancy complications.
But after analyzing the data from low-risk pregnancies alone, the U of M researchers still found that hospitals exhibited a wide — and troubling — variation in C-section rates, from 2.4 percent to 36.5 percent.
“To think that in a hospital with 100 deliveries there would be 36 percent of low-risk women having Caesareans is quite astounding,” said Katy Backes Kozhimannil, an assistant professor at the U of M’s School of Public Health and the study’s lead author, in a phone interview Monday.
But the low end in the data range was also troubling, she added, as it suggests some hospitals may not be performing C-sections when they are needed.
“There needs to be a better structure and system step up so that the decisions that are made by patients with their clinicians are in line with evidence-based practice and so they are more consistent for women across the country,” said Kozhimannil.
Most common surgical procedure
The Caesarean-delivery rate in the United States has climbed significantly in recent years, from 20.7 percent in 1996 to 32.8 percent in 2011, according to background information provided in the study. C-sections are now the nation’s most commonly performed surgical procedure.
Although C-sections can be lifesaving for mother and child alike, the procedure is still major surgery and thus poses significant health risks. For the mother, those risks include infection, blood clots and additional surgery. Women who have C-sections also tend to have more difficulty breastfeeding and may experience medical complications with future deliveries. For the infant, being born via a C-section increases the risk of respiratory and other lung problems.
C-section deliveries are also more costly than vaginal deliveries — an average of $12,739 compared to $9,048 for private health insurers, according to 2010 data. The added cost of a C-section delivery places a significant financial burden on Medicaid, which now pays for over 40 percent of all U.S. births. In 2009, state Medicaid programs spent more than $3 billion on C-section deliveries.
What’s driving the higher rates?
To explain the rise in the C-section rate, the U.S. medical community often points to increases in maternal factors associated with high-risk pregnancies (such as high blood pressure, obesity and pregnancy-related diabetes) as well as physicians’ concerns about liability and malpractice.
But those factors don’t fully explain the increase. Nor do they explain the wide variations in C-section rates that other studies have found geographically or that this new study found among hospitals.
Medical practices regarding childbirth are a likely driver behind those variations, said Kozhimmanil.
“It’s how the hospitals manage labor and delivery,” she explained. “It’s whether or not they decide to induce labor. It’s whether or not they decide to augment labor — to use Pitocin to move labor along — and whether or not they are using continuous electronic fetal monitoring, and what they decide is fetal heart spacing that is non-reassuring.”
“There is a growing consensus that there needs to be a consensus about how to manage those things,” she added, “but not so much that it burdens a clinician’s own expertise in his or her practice.”
Recommendations for change
To reduce the variations in hospital C-section rates, Kozhimannil and her colleagues recommend that hospitals do a better job of triaging maternal care. Women with high-risk pregnancies could be sent to hospitals, while those with low-risk pregnancies could be encouraged to have their babies in birthing centers where the focus would be on vaginal deliveries.
The researchers also recommended that more data about C-section rates be collected and measured as part of a hospital’s quality-of-care assessment. That information would help women make more informed decisions about childbirth-related medical decisions.
“Without good, clear, unbiased information, it’s hard for women to even ask the right questions,” said Kozhiminnal.