Most cord prolapses in term, vertex pregnancies. (Study of 52 Cases).

RANCHO MIRAGE, CALIF. -- Seven years' worth of experience at two Oregon hospitals calls into question several commonly held beliefs about risk factors for umbilical cord prolapse, since the majority of 52 cases occurred in term, vertex pregnancies.

Intriguingly, a 50% higher rate of prolapse was seen in patients induced at a community hospital than in the general population, prompting a call for further study of this possibly unrecognized risk factor for the obstetrical emergency.

Obstetricians Jodell J. Boyle from Good Samaritan Hospital in Corvallis, Ore., and Vein L. Katz from Sacred Heart Medical Center in Eugene, Ore., teamed up to explore the circumstances surrounding umbilical cord prolapse at their respective hospitals: Dr. Boyle's, a community hospital with 1,100 deliveries a year, and Dr. Katz's, a tertiary referral center with 2,500 deliveries a year.

"We chose to evaluate the incidence, risk factors, and outcomes of umbilical cord prolapse because anecdotally, in our experience, the traditional risk factors did not account for the majority of the patients we were seeing," Dr. Boyle explained during a presentation at the annual meeting of the Pacific Coast Obstetrical and Gynecological Society.

Traditionally umbilical cord prolapse has been associated with preterm labor, nonvertex presentations, and multiple gestations. Associated morbidity and mortality has been described as very high, with mortality rates of 50% cited in older studies and a 10%-30% mortality rate quoted in studies published in the last 15 years.

Modern obstetrical practices may have contributed to an improvement in those statistics, the Oregon study suggests.

The only deaths among 52 cases in 17,171 deliveries in the Oregon study were previable twins delivered at less than 24 weeks. Moreover, there ...