Pregnant women's likelihood of cesarean delivery in Massachusetts linked to choice of hospitals

March 18, 2013, Harvard School of Public Health

There is wide variation in the rate of cesarean sections performed at different hospitals across the U.S. and one explanation has been that hospitals with higher c-section rates serve greater numbers of women at high risk for the procedure. Now, a new study by researchers from Harvard School of Public Health (HSPH) and the Massachusetts Department of Public Health provides the strongest evidence to date that it's not just medical need that determines who has c-sections, but also something at the hospital level—in other words, the same woman would have a different chance of undergoing a c-section based on the hospital she chooses.

The findings suggest that certain hospitals' high rates of have more to do with characteristics of the hospitals themselves than with characteristics of their patients.

"Even after taking into account factors that put women at risk of having a c-section, such as age, and pre-existing , some hospitals still have higher rates of c-section delivery than others," said senior author S V Subramanian, professor of and geography at HSPH. Put simply, for two women with a similar observed risk profile, one might have a c-section delivery and one might not, depending on which hospital they go to, he said.

The study appears in the March 18, 2013 online issue of the journal PLOS ONE.

While can be a lifesaving procedure for an infant in distress, or when there are or other labor complications, c-sections that are not medically necessary can put mothers and babies at avoidable risk of infection, extend hospital stays and recoveries, and increase . In spite of these risks, c-section rates have been increasing in the U.S. over the past 17 years. Mirroring the national trend, cesarean deliveries in Massachusetts have increased steadily since 1997. In 2009, about one-third of all births in Massachusetts were by c-section—up 61% from 1998.

In 2008, the Massachusetts Department of invited local clinicians and researchers to partner with state health officials in a study to better understand why c-section rates have been rising in Massachusetts. The HSPH, Boston University, Massachusetts General Hospital, and Massachusetts Department of Public Health team, using data from the Pregnancy to Early Life Longitudinal data system, analyzed 228,864 births in Massachusetts' 49 hospitals with maternity services from 2004-2006—98% of all births during that period.

The researchers found that about 27% of first-time mothers in Massachusetts having single, vertex (head-first) presentation, full-term infants from 2004-2006 had c-sections. C-section rates in Massachusetts hospitals varied from 14% to 38% even among this low-risk group.

Previous research had been unable to offer clear answers on whether variations in hospitals' c-section rates had simply to do with hospitals' different case mix. But the new research findings, say the authors, show with more certainty that a mother's risk of c-section really is influenced by her choice of hospital. "This is the first time that anyone has shown this problem exists right here in Massachusetts, which is widely considered to be one of the world's premier health care hubs," said Mariana Arcaya, research scientist at the Harvard Center for Population and Development Studies and co-author of the study.

The findings suggest that hospital practices and culture are important determinants of a hospital's c-section rate, said lead author Isabel A. Cáceres, who was an epidemiologist at the Massachusetts Department of Public Health at the time of the study. Though this study did not pinpoint which hospital factors were at play, the authors highlighted previous studies suggesting that liability and insurance, being a teaching hospital, hospital admission practices, and the presence of midwives may influence c-section rates. Lack of clinical guidelines or standards on when a cesarean should be performed also may help explain why rates are so variable.

The researchers said that hospitals should re-examine their procedures for deciding when to perform c-sections to make sure that medical need—not other factors such as doctor preferences or fear of liability—determine how babies are delivered.

Explore further: Researchers find wide variation in cesarean delivery rates among US hospitals

More information: "Hospital differences in cesarean deliveries in Massachusetts (US) 2004-2006: the case against case-mix artifact," Isabel A Cáceres, Mariana Arcaya, Eugene Declercq, Candice M. Belanoff, Vanitha Janakiraman, Bruce Cohen, Jeffrey Ecker, Lauren A. Smith, S V Subramanian, PLOS ONE: March 18, 2013. http://dx.plos.org/10.1371/journal.pone.0057817

Related Stories

Researchers find wide variation in cesarean delivery rates among US hospitals

March 5, 2013
Cesarean delivery is the most common surgery in the United States, performed on 1.67 million American women annually. Yet hospital cesarean rates vary widely according to new research from the University of Minnesota's School ...

Too posh to push? The increasing trend for cesarean section

May 17, 2011
During the last thirty years there has been an increase in the number of babies born by Caesarean section. New research published in BioMed Central's open access journal BMC Public Health shows that there has also been a ...

Local efforts can stem the increasing unnecessary cesarean sections

July 26, 2011
Caesarean section rates are steadily increasing globally. Requiring two doctors to agree that a Caesarean section is the best way to deliver a baby, rather than just needing one opinion, providing internal feedback to doctors ...

Inducing labor is not associated with higher rates of cesarean sections

June 20, 2011
A new study published in the international Nordic journal Acta Obstetricia et Gynecologica Scandinavica (AOGS) reveals that inducing labor in the weeks around term, or from week 39 to week 41, is not connected with higher ...

Reduced baby risk from another cesarean

March 13, 2012
A major study led by the University of Adelaide has found that women who have had one prior cesarean can lower the risk of death and serious complications for their next baby - and themselves - by electing to have another ...

Recommended for you

Study shows how fetal infections may cause adult heart disease

January 23, 2018
Recent studies have shown that infants born prematurely have a higher risk of developing heart disease later in life. Now, a study led by researchers at the University of Washington School of Medicine in Seattle shows that, ...

Rise in preterm births linked to clinical intervention

January 18, 2018
Research at the University of Adelaide shows preterm births in South Australia have increased by 40 percent over 28 years and early intervention by medical professionals has resulted in the majority of the increase.

New report calls into question effectiveness of pregnancy anti-nausea drug

January 17, 2018
Previously unpublished information from the clinical trial that the U.S. Food and Drug Administration relied on to approve the most commonly prescribed medicine for nausea in pregnancy indicates the drug is not effective, ...

New study finds 'baby brain' is real, but the cause remains mysterious

January 15, 2018
So-called "baby brain" refers to increased forgetfulness, inattention, and mental "fogginess" reported by four out of five pregnant women. These changes in brain function during pregnancy have long been recognised in midwifery ...

Sleep quality improves with help of incontinence drug

January 12, 2018
A drug used to curtail episodes of urinary incontinence in women also improves quality of sleep, a researcher at the Stanford University School of Medicine reports.

Frozen embryos result in just as many live births in IVF

January 10, 2018
Freezing and subsequent transfer of embryos gives infertile couples just as much of a chance of having a child as using fresh embryos for in vitro fertilization (IVF), research from Ho Chi Minh City, Vietnam, and Adelaide, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.