Doctors need not go straight to Caesarean section when delivering twins, but can start with vaginal delivery of the first twin in many cases, researchers have found in a study led by UT Southwestern Medical Center.
Should the second-born twin turn out to require a Caesarean section, there is a slightly higher risk of infection for the baby and the mother, but that is easily treated and the risk of more serious complications for the second twin is not increased, the researchers found.
"It keeps the options open for women and providers who are motivated for vaginal delivery," said Dr. James Alexander, associate professor of obstetrics and gynecology at UT Southwestern and lead author of the two-year study, which appears in the October issue of the journal Obstetrics and Gynecology.
Although such "combined" delivery is relatively rare, there have been no large-scale studies to gauge how the mothers and babies fared after the procedure, Dr. Alexander said.
The UT Southwestern researchers are members of the Maternal-Fetal Medicine Units Network, a subset of the National Institutes of Health that comprises 14 university-based clinical centers and a data coordinating center.
They compared deliveries of 1,028 women at 13 network locations from 1999 to 2000, using data collected from a registry of information maintained by the group. This made the study the largest to address the question of combined-delivery safety, Dr. Alexander said.
All of the women in the study went through a period of labor. Ultimately, 849 had Caesarean sections of both twins, while 179 had a combined delivery of the first twin vaginally and the second by Caesarean section, usually because of a nonreassuring fetal heart rate or a poor position for delivery.
Four percent of women who had combined delivery developed chorioamnionitis, an infection involving the uterus, while 13 percent developed endometritis, an infection of the lining of the uterus. In contrast, 6 percent of the women who had Caesarean section of both twins developed chorioamnionitis, while 9 percent developed endometritis.
Dr. Alexander said the differences in infection rates were not statistically significant after accounting for the mothers' ages, length of pregnancy and characteristics of the labor, such as whether labor was induced or an antibiotic was used, and the time from onset of labor to delivery.
There were roughly equal rates of injury, seizures, low Apgar scores and other factors to the babies in both types of deliveries, showing that overall health was the same. The difference in rates of serious infection was not statistically significant, although the second-born twins from a combined delivery showed a slightly higher rate (9 percent versus 5 percent) than sets of twins being delivered by Caesarean section.
Dr. Kenneth Leveno, professor of obstetrics and gynecology at UT Southwestern, was also involved in the study. Researchers from the University of Alabama at Birmingham, Ohio State University, George Washington University Biostatistics Center, the National Institute of Child Health and Human Development (NICHHD), University of Utah, University of Chicago, University of Pittsburgh, Wake Forest University School of Medicine, Thomas Jefferson University, Wayne State University, University of Cincinnati, University of Miami, University of Tennessee, UT Health Science Center at San Antonio and Vanderbilt University also participated.
The study was funded by the National Institutes of Health.
Visit http://www.utsouthwestern.org/obgyn to learn more about gynecology and obstetrics clinical services at UT Southwestern.