Vaginal childbirth can so damage nerves and muscles that as many as one-quarter of women suffer later from urinary incontinence. Some women even opt to have caesarean sections to reduce their risk.
But there may be a way to give birth vaginally and avoid long-term pelvic-floor problems. That's what experts in midwifery, sports medicine and biomechanics hope to reveal in an unusual study at the University of Michigan. Their research will examine whether certain exercises and labor practices can reduce the incidence of urinary incontinence in the year following childbirth. Some of the approaches are based on knowledge from sports medicine about how muscles work and are damaged.
"We're trying to understand what it is about the way we do birth that might put women at risk for urinary incontinence," says Carolyn M. Sampselle, a University of Michigan professor of nursing and women's health who is leading the investigation. "We think there are some things we could be doing better."
For example, she says, contractions are often monitored by machines during labor. Doctors, nurses and midwives usually watch the monitor in the final stage of labor and tell women when to push to expel the baby. But preliminary research suggests that women push differently when told to do so than they do when pushing spontaneously, or when they feel like it. Women who are told to push often make a long, sustained, intense effort, while women in more natural settings will push in shorter bursts with more rests in between.
This could be important in terms of the amount of damage that is sustained to the muscles and nerves in the pelvic region, says Sampselle. Sports medicine studies have shown that slower, shorter stretches better protect muscles than sudden, intense stretching.
"I truly believe that what we've done with birth in the United States is take it out of the hands of women," she says. "We don't understand and honor women's bodies and the strengths they bring to childbirth. I suspect that women's bodies do intuitively know how to most effectively push."
As part of the study, which has just begun, obstetrical teams at two Ann Arbor hospitals will be asked to refrain from telling women how and when to push. In another part of the study, women will massage their perineum, the opening of the birth canal, with a lubricant beginning six weeks before pregnancy. A few minutes per day of gently stretching the vaginal opening could better prepare the tissues for childbirth, Sampselle says. This, too, is based on sports medicine and bioengineering principles that slow stretching over time strengthens muscles.
