LOS ANGELES — Vaginal delivery is a viable option for most women who've had a previous cesarean section and experience intrauterine fetal demise in a subsequent pregnancy, Mildred M. Ramirez, M.D., and her colleagues reported at the annual meeting of the Society for Gynecologic Investigation.
In a study of 209 women who faced this difficult situation, vaginal birth after cesarean section (VBAC) had an 86.7% success rate in 158 women who chose this procedure, according to the researchers' poster presentation.
Dr. Ramirez said in an interview that VBAC's success rate in this population was higher than in live births. She attributed the procedure's efficacy to there being no need for normal fetal monitoring and other attention to the well-being of the fetus.
A total of 51 women had a repeat cesarean section without attempting vaginal delivery. The surgical procedure was elective and not medically indicated in 37% of these patients, said Dr. Ramirez of the University of Texas Health Science Center at Houston Medical School.
The study involved data from the National Institute of Child Health and Human Development's Maternal Fetal Medicine Units (MFMU) Network. It represents a new subset analysis from a published observational study of more than 33,000 women in 19 hospitals (N. Engl. J. Med.2004; 351:2581-9; N. Engl. J. Med. 2004; 351:2647-9).
Only women with antepartum singleton pregnancies that resulted in intrauterine fetal demise at or after 20 weeks or when the fetus weighed at least 500 g were included in the new analysis. More than two-thirds of the women had undergone only one prior cesarean delivery; the rest had at least two. A total of 77 women had previously given birth vaginally, 38 of them after a cesarean section.
Labor had to be augmented in 14 patients, however, and induced in 116. Induction of labor appeared to play a role in the uterine rupture rate of 2.4%, which Dr. Ramirez said was higher than the 0.9%-2% rates previously reported for VBAC patients who delivered a live baby.
The rupture rate was even higher, 3.1%, in patients for whom labor had to be induced; four of five uterine ruptures occurred during induction. None of the patients who experienced rupture required a hysterectomy.
“We can probably modify the risk a little, maybe by not inducing patients so aggressively that we have a higher rate of rupture,” Dr. Ramirez said.
The transfusion rate was higher in the women who had repeat cesareans: 11.8% in the repeat cesarean group vs. 6.3% in the VBAC group. The VBAC group transfusion rate was higher than is usual with live births, according to Dr. Ramirez, who said the need for transfusion was often associated with the underlying condition that caused the death of the fetus.
The median hospital stay was three days, regardless of whether a woman chose VBAC or had a repeat cesarean section.
Dr. Ramirez said the study reinforced her preference for VBAC in these cases, but predicted physicians would reach different conclusions when advising patients. But, she said, the success rate of VBAC outweighs the physical and emotional toll of cesarean section.
“We have not even looked at the psychological component of how devastating it can be to undergo surgery for a dead baby,” she said.