Cord confusion trips up delivery

“Scrubs,” NBC, Dec. 7 Episode: “My Best Friend’s Baby’s Baby and My Baby’s Baby.”

The premise: Nurse Carla Espinosa (Judy Reyes) goes into labor. When she reaches the hospital, her cervix is 3 centimeters dilated. She is told to push. Then the obstetrician discovers that the fetus has a prolapsed umbilical cord and orders an emergency cesarean section. The baby is born with the cord wrapped around her neck (a nuchal cord) and is whisked away to intensive care but is soon pronounced fine.

The medical questions: Does a 3 centimeter dilation of the cervix signal the onset of full labor and the time to push? What is a prolapsed umbilical cord, and does it always lead to a C-section? How dangerous is nuchal cord to a newborn?

The reality: Active labor (when contractions become stronger and more regular and the cervix dilates faster) generally occurs when the cervix is more than 3 centimeters dilated. Active labor may last from 15 minutes to a few hours, but her labor appears to proceed much more rapidly, even taking into account the compressed time of a TV episode. She is asked to push before she seems to have a fully dilated cervix -- 10 centimeters -- which is not recommended because the baby can’t yet make it out and pushing can swell and even damage the cervix.

An umbilical cord prolapse most often requires an emergency C-section. In the case of an “overt umbilical cord prolapse,” the cord starts moving into the vaginal canal before the baby does. This happens in fewer than 1 in 300 births. An emergency C-section is required to keep the blood supply to the fetus from being cut off due to pressure from the baby’s head or constriction of the cord’s blood vessels due to a temperature drop.

Another type of prolapse -- an occult prolapse -- occurs when the cord is alongside the fetus rather than in front of it. In this case, surgery can sometimes be avoided by repositioning the cord farther from the baby.

The nuchal cord happens in 25% of births. It is usually not harmful, but during labor 20% of fetuses experiencing nuchal cord have a slowing heartbeat, which can lead to a C-section. When a doctor sees it at birth, he or she can easily slip the cord off the baby’s head.

This TV baby’s brief visit to the neonatal ICU because of a nuchal cord is unusual, says Dr. Diane Ashton, an obstetrician and deputy medical director of the March of Dimes. And nuchal cord and a prolapsed cord almost never occur simultaneously.

“The cord is simply not long enough to be dangling out of the mother’s vagina and also be wrapped around the baby’s neck,” Ashton says.

Dr. Marc Siegel is an internist and an associate professor of medicine at New York University’s School of Medicine. In the Unreal World, he explains the medical facts behind the media fiction. He can be reached at marc@doctor siegel.com.