If second twin is breech, vaginal delivery still safe: study of 107 vertex-nonvertex twins

OB/GYN News, Jan 1, 2004 by Damian McNamara

SANTIAGO, CHILE -- Vaginal delivery when a first twin is vertex and a second is nonvertex is a safe alternative to cesarean section, according to a study presented at the HGO World Congress of Gynecology and Obstetrics.

"There is controversy when twin A is vertex and twin B is nonvertex," said study investigator Dr. Anjan K. Chaudhury. But in his study of 107 such twin deliveries, vaginal delivery was not associated with increased neonatal morbidity, compared with cesarean delivery.

Dr. Chaudhury, of Boston University, and his colleagues reviewed 11,849 delivery records from March 1996 to September 2002 at Boston Medical Center. To be included in the study, the twins' gestational age had to be greater than 28 weeks, and each baby had to weigh at least 1,500 g. There were 107 twin pairs who met these criteria and were assessed further.

A total of 60 twin pairs were delivered vaginally and 39 were delivered via cesarean section. In eight pairs, the first twin was delivered vaginally and the second by emergency cesarean section.

"There was no statistically significant difference in well-being of twins delivered vaginally or via cesarean section," Dr. Chaudhury said. Specifically, there were no significant differences in the frequency of low (less than 7) 1- or 5-minute Apgar scores between twins delivered vaginally or via cesarean section. Similarly, there were no significant differences in neonatal intensive care unit admissions--21.5% of twins delivered vaginally, compared with 33% delivered via cesarean section.

Likewise, there were no statistically significant differences in the same outcomes for the eight twin pairs where the second was delivered via emergency cesarean section.

One possible limitation of the study is the relatively small number of twin pairs studied. There is a larger multicenter study underway in Canada to evaluate delivery outcomes in similar twin pairs.

Based on his findings, Dr. Chaudhury said, "It is safe to deliver a second twin as a breech extraction as long as there is continuous fetal monitoring, sufficient experience of the physician, and adequate ultrasound equipment available." In addition, the mother must have no contraindications for labor.

He added that many obstetric residents do not have adequate training for breech delivery as a result of its decreasing incidence in the United States.