U.S. hospitals have long been required to be able to start emergency Cesarean sections within 30 minutes, but neither compliance with this “decision-to-incision” time nor the associated rate of complications have ever been clinically measured.

Now, a multicenter trial of thousands of women, headed by researchers at UT Southwestern Medical Center, found that in severe emergencies, doctors appropriately performed deliveries well within 30 minutes. In less-threatening cases, exceeding that time didn’t increase complications.

“Clearly, physician judgment plays a critical role in determining the speed with which an emergency Cesarean is performed,” said Dr. Steven Bloom, interim chairman of the department of obstetrics and gynecology at UT Southwestern and the trial’s lead investigator.

The study is published in the July issue of Obstetrics and Gynecology.

The researchers collected data on 2,808 women who had emergency Cesareans at hospitals belonging to the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. At the time of the data collection, 1999 and 2000, the network comprised 13 medical centers and a data-coordinating center.

The study included only women having a first-time Cesarean and giving birth to single babies weighing 5.5 pounds or more.

About two-thirds of the cases, or 1,814, had their Cesarean deliveries begin within the 30-minute time frame, with most of those starting within 20 minutes.

In the group that met the time limit, 92.6 percent of the infants had no complications, while in the one-third who went over the limit, 95.4 percent had no complications. Statistically, there was no significant difference between those groups.

There was also no significant difference in the rates of maternal complications between the over- and under-30-minute groups.

In more obviously life-threatening cases, 98 percent of Cesarean deliveries were performed within 30 minutes.

In 1989, the American College of Obstetricians and Gynecologists set the guideline that a hospital offering obstetric care should have the capability of beginning a Cesarean delivery within 30 minutes. The important word is capability, not requirement, the researchers note.

“Having this potential should not be misconstrued to mean that it is required that all Cesareans commence within 30 minutes,” said Dr. Kenneth Leveno, professor of obstetrics and gynecology at UT Southwestern and study co-investigator.

Researchers from the National Institute of Child Health and Human Development; George Washington University; The University of Alabama at Birmingham; The Ohio State University; The University of Utah; The University of Chicago; The University of Pittsburgh; Wake Forest University; Thomas Jefferson University; Wayne State University; The University of Cincinnati; The University of Miami; The University of Tennessee, Memphis; The University of Texas Health Science Center at San Antonio and Vanderbilt University Medical Center also participated.

The work was supported by the National Institute of Child Health and Human Development.

UT Southwestern Medical Center