Use of Vacuum Extraction or Forceps Alone During Delivery Does Not Carry Excess Risk of Death or Injury to Newborns

Data Suggests Abnormal Labor Rather Than Mode of Delivery May be a Common Risk

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UC Davis School of Medicine and Medical Center

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The findings, published in the December 2 issue of the New England Journal of Medicine, are important because they provide hard data on rates of serious newborn injuries according to the method of delivery in a large population of women and shed light on the current controversy among practicing obstetricians, the Food and Drug Administration and the American College of Obstetricians and Gynecologists over the safe use of vacuum extraction devices during childbirth.

"Our study offers reassuring news to all obstetricians that intervention during labor, especially the use of vacuum extraction devices when needed, is still a safe, alternative method for delivery," says Dena Towner, an assistant professor of obstetrics and gynecology at UC Davis School of Medicine and Medical Center and lead author of the study. "Many studies have demonstrated the safety of soft vacuum extractors as compared with either metal vacuum extractors or forceps. Yet, vacuum extraction can result in major injury to the fetus, ranging from brachial plexus injury as a result of shoulder dystocia to scalp injuries, intracranial hemorrhage (bleeding into the brain), and skull fractures. Subgaleal hemorrhage, a specific condition whereby large volumes of blood collect between the scalp and skin, also has been strongly associated with vacuum extraction.

"But our study shows that vacuum extraction alone -- while it doubles the risk of intracranial hemorrhage in infants compared to those born by spontaneous vaginal delivery -- produces no statistically significant increased risk of injury to the infant than the use of forceps alone or C-section during labor. This means that once it is evident that a spontaneous vaginal delivery is not possible, either because the mother is exhausted or the baby is in distress, her physician should not be dissuaded from using vacuum extraction."

According to the study, intracranial hemorrhage in infants occurred in 1 of 2,750 pre-arranged C-section deliveries, 1 in 1,900 spontaneous deliveries, 1 in 907 C-section deliveries during labor, 1 of 860 vacuum extraction deliveries, and 1 of 664 forcep deliveries. While the chance of intracranial hemorrhage with vacuum extraction is double that found in spontaneous deliveries, injuries associated with vacuum extraction are still a rare occurrence, less than 1/2 percent. The highest incidence of injury to the infant, 1 in 256 births, occurred when both forceps and vacuum extraction were used. In the study, this combination produced an injury rate that was 7.5 times the rate associated with spontaneous delivery and 3.4 times that associated with vacuum extraction alone.

The study also showed that the incidence of death associated with spontaneous vaginal delivery was 1 per 5,000 births, with vacuum extraction was 1 per 3,333 births and with forceps delivery was 1 per 2,000 births. The incidence of death for C-sections was 8 in 10,000 births, but the exact cause of death is not known and may be attributed to confounding factors, such as the presence of a birth defect in the baby.

The UC Davis data helps put into perspective recent advisories from the Food and Drug Administration and the American College of Obstetricians and Gynecologists, a national medical organization representing over 39,000 physicians who provide health care for women. Based on voluntary reports to the FDA of 12 deaths and 9 serious injuries associated with vacuum extraction devices over the past four years (cited as a fivefold increase), the FDA issued a public health advisory in May 1998 urging the use of these devices for specific obstetrical indications. In September 1998, a special committee of the American College of Obstetricians and Gynecologists issued a statement reminding practitioners that the incidence of injury and death related to vacuum extraction devices is extremely low and that restricting their use would only increase the use of C-section and forcep deliveries.

"Our study confirms that vacuum extraction, when used appropriately, and other modes of assisted delivery, result in a low rate of serious injury to the newborn," says Towner. For the three-year study, UC Davis researchers evaluated the birth and death certificates and maternal and neonatal hospital-discharge records for 583,340 average weight infants born in California during 1992 through 1994. They grouped infants according to mode of delivery: 387,799 infants were delivered spontaneously, 59,354 by vacuum extraction, 117,425 by C-section, 15,945 by forceps, and 2,817 by the combined use of forceps and vacuum-extraction. Of the women who had C-sections, 84,417 were in labor at the time of delivery and 33,008 were not. In 2,343 of the women who were in labor when the C-section was performed, an attempt at operative vaginal delivery had been unsuccessful.

CONTACT: Carole Gan of UC Davis School of Medicine and Medical Center, 916-734-9047

Dec. 1, 1999