Doctors in scrubs walk down a hospital hallway.

The most common major surgery performed in the U.S. isn’t to remove an appendix or replace a knee. It’s to deliver babies by cesarean section, or C-section.

Roughly one out of every three babies born in this country—or about 1.3 million children each year—are delivered this way, instead of vaginally, according to data released earlier this year [pdf] by the Centers for Disease Control and Prevention (CDC). Yet the vast majority of women prefer to deliver vaginally, according to a January 2017 study in the journal Birth.

So what’s going on?

While being overweight, diabetic, or older can make it more likely for a woman to have a C-section, the biggest risk factor is “the hospital a mother walks into to deliver her baby, and how busy it is,” says Neel Shah, M.D., an assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School, who has studied C-section rates in the U.S. and around the world.

A Consumer Reports investigation of more than 1,300 hospitals across the U.S. echoes Shah’s findings. It reveals that C-section rates for low-risk deliveries in the U.S. vary dramatically from hospital to hospital, even between those located in the same communities.

When a C-Section Is Necessary

Sometimes, a C-section is absolutely necessary for a safe delivery, according to the American Congress of Obstetricians and Gynecologists (ACOG).

More on Pregnancy and Delivery

For example, an emergency C-section can be lifesaving if the placenta blocks the cervix, a condition called placenta previa. And it can sometimes make sense to schedule a C-section when, for example, the fetus isn’t properly positioned for birth. Cesareans can also be necessary if the mother has uncontrolled high blood pressure or diabetes, or when she is pregnant with twins, triplets, or other multiples.  

But for most pregnancies, which are low-risk, C-sections are not necessary: Researchers estimate that almost half of the C-sections performed in the U.S. are not required. And performing a surgical birth can pose added risks to the mother and her child and also raise costs, research shows.

While many medical institutions across the U.S. are now taking steps to prevent unnecessary C-sections, women themselves can take steps to reduce their own risk of having one, including through their choice of hospital. A study in the journal Birth, for example, found that more than half of women said they would travel 20 miles farther to have their baby at a hospital with a C-section rate that was 20 percentage points lower.

“Women understand that the quality of care differs depending on the hospital they pick, and this study shows that it is possible for women, if properly armed with data, to vote with their feet and send a signal to the medical community by choosing—if possible—a hospital with a lower C-section rate,” explains Doris Peter, Ph.D., former director of the Consumer Reports Health Ratings Center.

That said, some women may not have the option to choose a different hospital. (For more on what else you can do to reduce your risk of a C-section, see “How to Reduce Your Risk of a C-Section.”) Reducing C-section risk for women is ultimately the responsibility of hospitals and providers, Peter says. And progress is being made in the medical community.

For example, ACOG and the Society for Maternal-Fetal Medicine (SMFM)—the nation’s two leading medical organizations that focus on childbirth—issued recommendations in 2014 aimed at safely reining in unnecessary C-sections. And ACOG recommendations released last year discourage the types of medical interventions in low-risk deliveries that can increase the risk of a C-section.

“No one is saying that C-sections are never necessary, and no woman should feel bad if they end up needing one,” says Elliott Main, M.D., medical director of the California Maternal Quality Care Collaborative, a nonprofit organization that works to improve outcomes for mothers and babies. “The goal is to better support women in labor so that indications for C-sections do not develop,” he says.

The Danger of Unnecessary C-Sections

When C-sections aren’t medically indicated, they may be more likely to harm mothers and babies than to help them.

“As the cesarean rate went up from 1995 to 2007, we didn’t see a decrease in neonatal mortality in our country related to cesarean birth,” says Aaron B. Caughey, M.D., chair of the Department of Obstetrics and Gynecology at Oregon Health & Science University School of Medicine in Portland and a lead author of the 2014 ACOG/SMFM recommendations. “In fact, if anything, we started to see an increase in maternal mortality.”

Harvard’s Shah points out that C-sections are major surgery, with all of the risks of any hospital procedure. “Unnecessary C-sections may be responsible for up to 20,000 major surgical complications a year, including everything from sepsis [a life-threatening complication of certain infections] to hemorrhage to organ injury,” he says. The challenge is identifying the ones that aren’t necessary and implementing measures to stop them from occurring.

Life-threatening complications are very rare whether babies are born vaginally or by C-section. But women with low-risk pregnancies undergoing their first C-section were three times more likely to die or suffer serious complications—such as blood clots, heart attack, and major infections—compared with women delivering vaginally, according to a 14-year analysis of more than 2 million women in Canada published in 2007 and cited by the ACOG guidelines. And a research review published earlier this year found that children delivered via C-section had a higher risk of asthma and obesity, and that their mothers had an increased risk of uterine rupture, placenta previa, and stillbirth during subsequent pregnancies.

Another reason to avoid a medically unnecessary C-section: It multiplies the chance that a woman’s future births will also be delivered that way. “Right now in the U.S., if you get a C-section the first time, you have a 90 percent chance of getting another one the second time,” Shah says. (Increasing the rate of vaginal births after cesareans is something ACOG is actively working on.)

And that's why efforts to reduce C-sections focus especially on preventing primary, or first-time, C-sections, Caughey adds.

And while some people may assume that C-sections are easier on mothers than vaginal births, it usually takes women longer to recover after a cesarean. 

Vaginal delivery for low-risk pregnancies may also be better for babies. They are less likely to suffer breathing problems and more likely to be breastfed, perhaps because it’s easier to get breastfeeding going when mothers are not recovering from major surgery.

Finally, C-sections cost almost 30 percent more than vaginal births. The average cost for a C-section in the U.S. today is $16,038, compared with $12,560 for a vaginal birth. The cost for any delivery can vary by as much as $10,000 across the U.S., according to, a nonprofit organization that publishes healthcare cost data.

Why C-Section Rates Are So High

Much of the conventional wisdom for why rates have increased points to mothers—but that conventional wisdom doesn’t bear out, Shah says.

“Some people say moms are older, there’s more diabetes, there’s more hypertension, there’s more obesity, there’s more IVF [in-vitro fertilization], there’s more twins—but all of that collectively only explains a small amount of the increase over time," he says.

Neither does patient demand appear to be behind the rates. Less than 1 percent of women actually asked for a C-section without a medical reason for it, according to a survey of 1,314 new mothers conducted by Childbirth Connection, part of the nonprofit National Partnership for Women and Families. Of the 252 women in that survey who had a C-section, only one had requested it without a medical reason.

The use of continuous fetal heart monitoring—which can create anxiety about non-emergencies—and doctors’ perceptions of prolonged labor (and when it’s appropriate to intervene) are two of the biggest contributors to increased C-section rates for low-risk deliveries, Shah explains. “Those are where we see the most variation and discretion in the decision to do the C-section, where there’s the most room for interpretation from the physician,” he says.

Heart-rate monitors appeared in the early 1970s with the promise of decreasing newborn deaths by tracking the baby’s heart rate in real time, but the only thing they do in low-risk births is “reliably increase the C-section rate,” he says. That’s because monitors only accurately identify a real problem about 15 percent of time. “It’s really low, so that means most of the time, you’re overreacting."

And labor dystocia—the technical term for prolonged labor—can be in the eyes of the beholder. Some providers may intervene because they think labor is moving too slowly and that longer labors lead to complications, says Amy Romano, a certified nurse midwife (CNM) and senior vice president of clinical programs for Baby+Company, a network of midwife-led maternity clinics based in North Carolina. But those assumptions about how long labor should take are based on information gathered in the 1950s.

ACOG released guidelines last year to help clear up when healthcare providers should act and when they should be patient and let labor take its course, though Caughey doesn't expect practices to change immediately. “Changing that takes time,” he notes. “That appears to be starting to happen, but will be a slow transformation.”

Add to that the pressure that can occur when the delivery floor gets unexpectedly busy, and even well-intentioned doctors can end up rushing a birth to free up beds, especially if the staff is short-handed. “It can be really, really quiet, and then an hour later it’s like a bus pulls up and drops off 10 pregnant women,” Shah says. “The environment around them makes it harder to do the right thing—fewer staff, fewer beds, more patients.”

In the U.S., far fewer babies are born on holidays such as the Fourth of July or days around Thanksgiving or Christmas, Consumer Reports found when we examined three years' worth of data on births compiled for us by the Centers for Disease Control and Prevention. That occurs partly because hospitals tend to schedule C-sections and inductions for when they are well staffed, during the week, Shah explained.

But nature’s timeline cannot be predicted: If a woman shows up Christmas Eve in labor, the fact that so few staff are working could increase her likelihood of delivering a cesarean birth.

How Hospitals Can Improve

Lowering C-section rates can take years of hard work, according to Robert Silverman, M.D., chief of the Department of Obstetrics and Gynecology at Crouse Hospital in Syracuse, NY. His hospital had the lowest C-section rate in our ratings for low-risk pregnancies among hospitals with at least 3,500 births, at just 7 percent.

"We have spent literally decades on educating the physicians at our institution about really good prenatal care," Silverman says. "Everything we can do to prevent that first C-section from occurring, we try to do."

And there are professional organizations, like the nonprofit California Maternal Quality Care Collaborative (CMQCC), that provide hospitals with guidance on evidence-based strategies and practices that can lower C-section rates—by providing data to doctors as well as to the public, for example.

Making a hospital’s C-section rate public not only helps families choose a hospital, but can also motivate hospitals and doctors to change their practices. “There’s a lot of denial of the problem of high C-section rates, and we need to overcome it,” says Main, who notes that simply having the data is an important first step in correcting the problem. In fact, three hospitals that were part of a pilot project with CMQCC in 2016 were able to successfully reduce their C-section rates.

And Caughey notes that hospitals should track not just C-section rates, but the number of newborns who have complications or die in their facilities.   

Similar examples of improvement include Carolinas HealthCare System, in Charlotte, NC, which used a data-driven approach and safely lowered their C-section rate for low-risk deliveries from 27 percent to 21.8 percent over a two-year period. Beth Israel Deaconess Medical Center, in Boston, MA, reduced its C-section rate from 34.8 percent to 21.2 percent over eight years, using several evidence-based strategies, including sharing data with providers on their C-section rates. And this reduction occurred without increasing complications in babies or mothers.

In the meantime, while hospitals around the country are working to lower their rates of unnecessary C-sections, women can arm themselves with CR’s detailed data about C-section rates at their local hospitals so they can make an informed decision about where to give birth, says Peter.

For more on what you can do to avoid an unnecessary C-section, see our article “How to Avoid a C-Section Procedure.”