Among women whose previous cesarean was in a multiple pregnancy, those who chose a trial of labor were more likely to have had a prior vaginal delivery (OR 2.62, 95% CI 1.88–3.64), more likely to have had a vaginal delivery after their one previous cesarean delivery (OR 5.90, 95% CI 3.43–10.14), and were of higher parity (OR 1.42, 95% CI 1.24–1.64) but lower body mass index (BMI) at delivery (OR 0.96, 95% CI 0.94–0.98) than were those women who chose to have an elective cesarean delivery. We also compared those cases who had a successful trial of labor (n = 476) with those whose trial of labor was unsuccessful (n = 80). Those women who had a successful trial of labor had higher parity than were those whose trial of labor was unsuccessful and were also more likely to have had both a previous vaginal delivery and a previous intervening successful trial of labor (Table 3). Although not older than those whose trial of labor was unsuccessful, those women who had a successful trial of labor also had lower BMIs at admission for delivery.
Gestational age at delivery, birth weight, perinatal death rates, and low 5-minute Apgar scores for infants of women whose one previous cesarean delivery was for a multiple pregnancy were not different from those of women whose one previous cesarean delivery was for a singleton pregnancy. However, newborns of women attempting a trial of labor whose one previous cesarean delivery was for a multiple pregnancy were less likely to require neonatal intensive care unit admission than were newborns of women attempting a trial of labor whose one previous cesarean delivery was for a singleton pregnancy (Table 4).
Although enthusiasm for trial of labor after previous cesarean delivery has diminished over the preceding decade, it remains a common procedure, and there remain patient subgroups for which insufficient data exist to provide adequate patient counseling. One such group is women with one previous cesarean delivery done for a multifetal pregnancy and who are now pregnant with a singleton pregnancy. Given the progressive increase in multifetal pregnancy1 as well as the increasing frequency with which these pregnancies are delivered by cesarean,6 one can reasonably expect the numbers of such cases to increase in coming years.
The database from which our cases were identified consisted of all pregnant women in 19 participating institutions who delivered by cesarean with at least one previous cesarean delivery and who reached at least 20 weeks of gestation or delivered an infant of 500 g or more in the current pregnancy, either abdominally or vaginally.5 This database was originally collected to determine and compare success rates of trial of labor and uterine rupture in women with single and with multiple prior cesarean deliveries. Because this was not a randomized trial, the cases and controls identified for this report may be subject to clinical biases, in particular, toward selection of candidates for a trial of labor compared with repeat cesarean delivery.
Among women whose previous cesarean delivery was in a multiple pregnancy, women who underwent a trial of labor were more likely to have had a previous vaginal delivery, either before or after their cesarean delivery, and lower BMIs at delivery than were women who were delivered by elective cesarean delivery. These same criteria also were associated with a higher likelihood of successful vaginal delivery in those women undergoing a trial of labor (Table 3). Likewise, the lower likelihood of neonatal intensive care unit admissions in infants of women attempting a trial of labor after one previous cesarean delivery for multifetal pregnancy, compared with those infants of women attempting a trial of labor after one previous cesarean delivery for a singleton pregnancy (Table 4), is likely related to the higher percentage of previous vaginal deliveries and successful vaginal births after cesarean in the former group (Table 1).
These data suggest that a trial of labor remains a reasonable consideration for women pregnant with a singleton vertex pregnancy whose one previous cesarean delivery was for a multifetal pregnancy. Outcomes of a trial of labor after a cesarean delivery for a prior multifetal gestation are comparable to trial of labor after a cesarean delivery for a singleton gestation. The increasing rates of multiple pregnancy and cesarean delivery in the United States suggest that these data will be increasingly applicable for patient counseling.
1. Hoyert DL, Mathews TJ, Menacker F, Strobino DM, Guyer B. Annual summary of vital statistics: 2004 [published erratum appears in Pediatrics 2006;117:2338]. Pediatrics 2006;117:168–83.
3. Scott JR. Avoiding labor problems during vaginal birth after cesarean delivery. Clin Obstet Gynecol 1997;40:533–41.
4. Landon MB, Leindecker S, Spong CY, Hauth JC, Bloom S, Varner MW, et al. The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean. Am J Obstet Gynecol 2005;193:1016–23.
5. Landon MB, Hauth JC, Leveno KJ, Spong CY, Leindecker S, Varner MW, et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery. N Engl J Med 2004;351:2581–9.
6. Ananth CV, Joseph KS, Smulian JC. Trends in twin neonatal mortality rates in the United States, 1989 through 1999: influence of birth registration and obstetric intervention. Am J Obstet Gynecol 2004;190:1313–21.
In addition to the authors, other members of the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network are as follows:
Ohio State University — J. Iams, F. Johnson, S. Meadows, H Walker
University of Alabama at Birmingham — J. Hauth, A. Northen, S. Tate
University of Texas Southwestern Medical Center — S. Bloom, J. McCampbell
University of Utah — M. Belfort, F. Porter, B. Oshiro, K. Anderson, A. Guzman
University of Chicago — J. Hibbard, P. Jones, M. Ramos-Brinson, M. Moran
University of Pittsburgh — K. Lain, M. Cotroneo, D. Fischer, M. Luce
Wake Forest University — P. Meis, M. Swain, C. Moorefield, K. Lanier, L. Steele
Thomas Jefferson University — A. Sciscione, M. Talucci, M. Pollock
Wayne State University — M. Dombrowski, G. Norman C. Sudz
University of Cincinnati — H. How, N. Elder
Columbia University — F. Malone, M. D'Alton, V. Carmona, H. Husami
Brown University — H. Silver, J. Tillinghast, D. Catlow, D. Allard
Northwestern University — D. Gradishar, G. Mallett
University of Miami, Miami, FL — G. Burkett, J. Gilles, J. Potter, F. Doyle
University of Tennessee — W. Mabie, R. Ramsey
University of Texas at San Antonio — D. Dudley, D. Conway
University of North Carolina — K. Moise, K. Dorman, S. Brody, J. Mitchell
University of Texas at Houston — L. Gilstrap, M. Day, M. Kerr
Case Western Reserve University — P. Catalano, C. Milluzzi, B. Slivers
The George Washington University Biostatistics Center — S. Gilbert, C. MacPherson, S. Weiner
National Institute of Child Health and Human Development — D. McNellis, S. Pagliaro