When a woman is giving birth, having a “coach” tell her to push during contractions makes almost no difference in shortening labor, and may actually increase her risk of subsequent problems with her bladder, researchers at UT Southwestern Medical Center have found.

For the most part, it doesn’t matter whether the mother is coached or not, the researchers report in the January issue of the American Journal of Obstetrics and Gynecology. And researchers noted that further study must be done to determine if bladder problems were permanent.

“Oftentimes, it’s best for the patient to do what’s more comfortable for her,” said Dr. Steven Bloom, lead author of the paper and interim chair of obstetrics and gynecology at UT Southwestern.

In the study, UT Southwestern researchers focused on second-stage labor – the time in which the cervix is fully dilated and the baby begins to descend. This report follows an earlier one that found a rise in pelvic-floor problems among coached women.

The new study involved 320 women at Parkland Memorial Hospital who were giving birth for the first time, had uncomplicated pregnancies and did not receive epidural anesthesia. They were randomly assigned, with both groups tended by nurse-midwives. Of the two groups, 163 were coached to push for 10 seconds during a contraction, and 157 told to “do what comes naturally.”

For women who were randomly assigned to the coaching group, the second stage of labor was shortened by 13 minutes, from 59 to 46 minutes.

“There were no other findings to show that coaching or not coaching was advantageous or harmful,” Dr. Bloom said.

The earlier study, reported in the May issue of Obstetrics and Gynecology, involved the same group of women. In it, researchers investigated whether coaching causes long-term problems to the mother’s pelvic region.

Of the 320 women in the study, 128 returned for testing three months later. The coached women, researchers reported, had smaller bladder capacity and a decreased “first urge to void” – the volume at which a woman wanted to pass urine. However, over time, the bladder function can return to normal.

“Whether or not these functional changes have long-term consequences, I’m not ready to say,” said Dr. Kenneth Leveno, professor of obstetrics and gynecology and senior author of both studies. “We don’t want to alarm patients about this.”

Other UT Southwestern researchers participating in the studies were Drs. Brian Casey, Joseph Schaffer and Donald McIntire, all associate professors of obstetrics and gynecology. Dr. Schaffer was lead author of the earlier study, in which Dr. M.A. Nihira of the University of Oklahoma also contributed.

The studies were supported by the National Institute of Child Health and Human Development.