Neonatal Outcomes May Be Better With Vaginal Birth After Cesarean Delivery

News Author: Laurie Barclay, MD
CME Author: Charles Vega, MD, FAAFP

June 3, 2009 — Neonates born after elective subsequent cesarean delivery have significantly higher rates of respiratory morbidity and neonatal intensive care unit (NICU) admission and longer length of hospital stay vs those with vaginal birth after cesarean (VBAC), according to the results of a retrospective cohort study reported in the June issue of Obstetrics & Gynecology.

"Controversy remains on whether a trial of labor or an elective repeat cesarean delivery is preferable for a woman with a history of cesarean delivery," write Beena D. Kamath, MD, MPH, from the University of Colorado School of Medicine in Denver, and colleagues. "Historically, concerns regarding the increased risk of uterine rupture and perinatal asphyxia in trial of labor after cesarean compared with planned repeat cesarean have swayed obstetricians away from recommending a trial of labor after cesarean delivery; however, the absolute risk of perinatal asphyxia remains small."

The goals of this study were to compare the outcomes of neonates born by elective subsequent cesarean delivery vs VBAC in women with 1 previous cesarean delivery and to compare the cost differences between these procedures. The study cohort consisted of 672 women with 1 previous cesarean delivery and a singleton pregnancy at or after 37 weeks of gestation. Participants were categorized based on their intention to have an elective subsequent cesarean delivery or a VBAC, whether successful or failed. The main endpoints of the study were NICU admission and measures of respiratory morbidity.

Compared with the VBAC group, neonates born by cesarean delivery had higher NICU admission rates (9.3% vs 4.9%; P = .025). Rates of oxygen supplementation were also higher in the subsequent cesarean group for delivery room resuscitation (41.5% vs 23.2%; P < .01) and after NICU admission (5.8% vs 2.4%; P < .028). The rates of delivery room resuscitation with oxygen were lowest in neonates born by VBAC and highest in neonates delivered after failed VBAC.

Although the costs of elective subsequent cesarean delivery were significantly higher vs VBAC, the highest costs for the total birth experience were for failed VBAC, considering both delivery and NICU use.

"In comparison with vaginal birth after cesarean, neonates born after elective repeat cesarean delivery have significantly higher rates of respiratory morbidity and NICU-admission and longer length of hospital stay," the study authors write.

Limitations of this study include relatively short postpartum follow-up of the mothers to determine the additional costs of postsurgical complications and insufficient data to allow estimation of costs other than those for hospital care.

"Given the increasing rates of primary cesarean delivery and the concomitant decrease in VBACs, once a woman has had a primary cesarean delivery, we must consider the risks that this places on her subsequent deliveries and subsequent neonates," the study authors conclude. "Indeed, this argues for greater selectivity in performing a cesarean delivery in the first place, and certainly a greater need for counseling before a primary elective cesarean delivery. As investigators continue to search for ways to make cesarean delivery safer, we may be better served by exploring other means for reducing overall cesarean delivery rates and recognizing our own preoccupation with the individual that will be our patient, whether it be mother or neonate."

The study authors have disclosed no relevant financial relationships.

Obstet Gynecol. 2009;113:1231-1238.

Clinical Context

The rate of cesarean delivery has reached an all-time high in the United States, and the current study provides an overview of the epidemiology of cesarean delivery. In 2006, 31.1% of all deliveries were via cesarean, and this rate was fueled by an increase in the rate of primary cesarean delivery by 60% between 1996 and 2005.

Women with a primary cesarean delivery have a greater than 90% chance of having another cesarean delivery. Overall, more than half of cesarean deliveries are performed electively, before the onset of labor.

The current study examines neonatal outcomes in women with a history of primary cesarean delivery, with the primary variable being VBAC vs subsequent elective cesarean delivery.

Study Highlights

• The study was a retrospective review of cases at 1 Colorado hospital between 2005 and 2008.
• Researchers focused on women with a history of 1 previous cesarean delivery who were pregnant with a singleton pregnancy at 37 weeks or more of gestation. 51% of these women had planned an elective subsequent cesarean delivery, and 49% had planned for VBAC.
• The primary outcome of the study was admission to the NICU. Researchers conducted a multivariate regression analysis to account for the effects of maternal demographic and disease factors as well as birth factors on the study outcome. Other outcomes included the need for neonatal resuscitation and the cost of care.
• 672 women were included in the analysis. The mean maternal age was 29 years, and approximately half of women were of Hispanic origin.
• 35.6% of the study cohort had a planned elective cesarean delivery without labor, 15.5% had an elective cesarean delivery after the onset of labor, 36.3% of women had a successful VBAC, and 12.6% had a failed VBAC requiring cesarean delivery.
• Older women and women with higher educational achievement were more likely to have an elective subsequent cesarean delivery.
• 9.3% of neonates delivered by elective subsequent cesarean delivery required admission to the NICU vs only 4.9% of neonates delivered by intended VBAC. The adjusted odds ratios for NICU admission in neonates delivered with elective subsequent cesarean delivery without and with labor vs successful VBAC delivery were 2.93 and 2.26, respectively.
• Infants in the cesarean group were more likely to require blow-by oxygen and continuous positive airway pressure after delivery vs infants delivered by VBAC, and they also had higher rates of NICU admission for hypoglycemia.
• Conversely, infants delivered by VBAC were more likely to require bag mask ventilation and endotracheal intubation after delivery.
• Infants delivered via cesarean after a failed VBAC had rates of NICU admission similar to rates of admission in the elective subsequent cesarean delivery group. However, infants delivered after failed VBAC required the most resuscitation efforts after delivery.
• Factors associated with failed VBAC included chorioamnionitis and induction of labor.
• Neonates delivered at 37 weeks of gestation required more resuscitation efforts vs more mature neonates.
• Successful VBAC was associated with the shortest hospital stay and the lowest overall cost of care. Although failed VBAC was associated with the highest cost of care from all groups, planned VBAC still cost less than planned elective subsequent cesarean delivery overall.

Clinical Implications

• The rate of cesarean deliveries in the United States was 31.1% in 2006, and an increase in the rate of primary cesarean deliveries was primarily responsible for this high rate. In addition, women with a primary cesarean delivery have a greater than 90% chance of having another cesarean delivery, and more than half of all cesarean deliveries are performed electively, before the onset of labor.
• The current study finds that the rate of NICU admission is higher in infants delivered via elective subsequent cesarean delivery vs VBAC. Overall, elective subsequent cesarean delivery was estimated to be a more costly strategy.