July 30, 2007

CONTACT: Kate Olderman Tavella
(215) 349-8369

Penn Study Shows Lower Cesarean Rates Associated With Preventive Labor Induction
Finding Challenges Conventional Belief that Inducing Labor Leads to Increases in C-Sections

(PHILADELPHIA) – At a time when national rates of cesarean delivery have climbed above 30%, a four-year study of patients receiving an alternative method of obstetric care experienced a significantly lower rate of cesarean births, according to a study published in the current issue of the Annals of Family Medicine. The study, conducted by researchers at the University of Pennsylvania School of Medicine, reports that a cohort of women exposed to a safe, alternative method of maternity care had a 5.3 percent cesarean delivery rate compared to a 11.8 percent of women who received more traditional care.

The new approach uses a method of pregnancy dating and risk scoring to estimate an optimal time of delivery for each pregnancy. If spontaneous labor has not occurred by this time, preventive labor induction is performed, increasing the likelihood that labor occurs before the fetus has grown too large for the maternal pelvis or before the placenta has grown too old to support the fetus during labor.

The new approach is called the Active Management of Risk in Pregnancy at Term (AMOR-IPAT). AMOR-IPAT evaluates the risk profile for each pregnancy, and uses each risk profile to estimate an optimal time of delivery. Preventive labor induction is used if a woman does not develop spontaneous labor by the upper limit of her optimal time of delivery. Within the term period, the greater the number and severity of risk factors, the earlier preventive labor induction is offered.

The findings support a preventive approach to reduce cesarean deliveries, and challenge the current belief that the use of labor induction leads to higher cesarean delivery risk. The study was conducted at a rural New England hospital and involved 1,869 women. The results of this study are similar to a 400-patient study from an urban setting, published two years ago, that reported a 4 percent cesarean delivery rate in women exposed to AMOR-IPAT.

“The estimation of an optimal time of delivery, using a combination of accurate pregnancy dating and risk-factor scoring, is a concept that suggests a potentially powerful preventive approach to obstetric care,” says lead researcher, James M. Nicholson, MD, Assistant Professor of Family Medicine and Community Health at Penn. “By using preventive labor induction to ensure that every women enters labor during her optimal time for vaginal delivery, the AMOR-IPAT approach provides significant health benefits for mothers and babies.”  Dr. Nicholson also reports that the use of prostaglandin E2 gel for pre-induction cervical ripening, specifically for women scheduled for preventive labor induction who had an unripe cervix, was a key element of in the successful application of AMOR-IPAT.  

Vaginal births carry with them a lower rate of morbidity than cesarean births, including decreased chances for post-partum infection and less blood loss. In addition, lower rates of C-section also correspond to lower usage rates in neo-natal intensive care units, shorter lengths of hospital stay for mother and baby, and fewer complications in subsequent pregnancies.

The pilot study for this project was funded by Forest Pharmaceuticals, Inc., in 2000.  In addition, Forest Pharmaceuticals has provided, at no cost, its dinoprostone vaginal insert cervical ripening product for use in an ongoing randomized clinical trial of AMOR-IPAT.  This prospective study, which is supported by the NICHD/NIH and the Pennsylvania Hospital Foundation, is being performed within the University of Pennsylvania Health System.


PENN Medicine is a $3.5 billion enterprise dedicated to the related missions of medical education, biomedical research, and excellence in patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.

Penn's School of Medicine is currently ranked #3 in the nation in U.S.News & World Report's survey of top research-oriented medical schools; and, according to most recent data from the National Institutes of Health, received over $379 million in NIH research funds in the 2006 fiscal year. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

The University of Pennsylvania Health System includes three hospitals — its flagship hospital, the Hospital of the University of Pennsylvania, rated one of the nation’s “Honor Roll” hospitals by U.S.News & World Report; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center — a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home care and hospice.

This release is available online at