Three pulls, three hours of pushing the limit in operative vaginal delivery: expert opinion.(Obstetrics)

MAUI, HAWAII -- When considering the safety of an operative vaginal delivery, the magic number seems to be three.

Results of three studies in recent years show that risks increase significantly with attempted operative vaginal delivery if the mother has been pushing in labor for longer than 3 hours or if the physician pulls more than three times on the fetus with forceps or a vacuum extractor, Dr. Michael Belfort said at a conference on obstetrics, gynecology, perinatal medicine, neonatology, and the law.

The number one also plays an important role. One instrument should be used, not sequential instruments, and the one doing the pulling (the physician) should be experienced at operative vaginal deliveries, said Dr. Belfort, director of maternal fetal medicine and professor of ob.gyn. at the University of Utah, Salt Lake City.

Ignoring these rules increases the risks for neonatal intracranial bleeds or seizures, facial nerve and brachial plexus lesions, neonatal trauma, admissions to neonatal intensive care, and maternal trauma above that of a normal vaginal delivery or cesarean section.

The first study to examine how many pulls are safe during operative vaginal delivery compared outcomes after successful operative vaginal delivery, failed operative vaginal delivery followed by C-section, or labor and C-section alone in 399 term singleton pregnancies with complete dilatation after 3 hours in the second stage of labor. The risk of neonatal trauma quadrupled after failed operative vaginal delivery, compared with C-section after labor in this prospective cohort study.

Pulling more than three times with forceps or vacuum increased the risk for neonatal trauma fourfold if the pulls succeeded and sevenfold if the operative vaginal delivery ...