Obstetrics & Gynecology:
Trial of Labor After One Previous Cesarean Delivery for Multifetal Gestation
Varner, Michael W. MD1; Thom, Elizabeth PhD2; Spong, Catherine Y. MD3; Landon, Mark B. MD4; Leveno, Kenneth J. MD5; Rouse, Dwight J. MD6; Moawad, Atef H. MD7; Simhan, Hyagriv N. MD8; Harper, Margaret MD9; Wapner, Ronald J. MD10; Sorokin, Yoram MD11; Miodovnik, Menachem MD12,13; Carpenter, Marshall MD14; Peaceman, Alan MD15; O'Sullivan, Mary J. MD16; Sibai, Baha M. MD17; Langer, Oded MD18; Thorp, John M. MD19; Ramin, Susan M. MD20; Mercer, Brian M. MD21; for the National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU)
From the Departments of Obstetrics and Gynecology at 1University of Utah, Salt Lake City, Utah; 2George Washington University Biostatistics Center, Washington, DC; 3National Institute of Child Health and Human Development, Bethesda, Maryland; 4Ohio State University, Columbus, Ohio; 5University of Texas-Southwestern, Dallas, Texas; 6University of Alabama at Birmingham, Birmingham, Alabama; 7University of Chicago, Chicago, Illinois; 8University of Pittsburgh, Pittsburgh, Pennsylvania; 9Wake Forest University, Winston-Salem, North Carolina; 10Thomas Jefferson University, Philadelphia, Pennsylvania; 11Wayne State University, Detroit, Michigan; 12University of Cincinnati, Cincinnati, Ohio; 13Columbia University, New York, New York; 14Brown University, Providence, Rhode Island; 15Northwestern University, Chicago, Illinois; 16University of Miami, Miami, Florida; 17University of Tennessee, Memphis, Tennessee; 18University of Texas-San Antonio, San Antonio, Texas; 19University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; 20University of Texas-Houston, Houston, Texas; and 21Case Western Reserve University, Cleveland, Ohio.
* For members of the NICHD MFMU, see the Appendix.
Supported by the following grants from the National Institute of Child Health and Human Development: HD21410, HD21414, HD27860, HD27861, HD27869, HD27905, HD27915, HD27917, HD34116, HD34122, HD34136, HD34208, HD34210, HD40500, HD40485, HD40544, HD40545, HD40560, HD40512, and HD36801.
The authors thank Frances Johnson, RN, and Julia McCampbell, RN, for participating in protocol development and coordination between clinical research centers, and Sharon Gilbert, MS, for protocol and data management. Cora MacPherson, PhD, and Steven Weiner, MS, assisted with the statistical analysis.
Presented at the annual meeting of the Society for Maternal-Fetal Medicine, Miami, Florida, February 2–4, 2006.
Corresponding author: Michael W. Varner, MD, Department of Obstetrics and Gynecology, University of Utah School of Medicine, 30 North 1900 East, Room 308, Salt Lake City, UT 84132; e-mail: firstname.lastname@example.org.
Financial Disclosure The authors have no potential conflicts of interest to disclose.
OBJECTIVE: To estimate success rates and risks with a trial of labor after one previous cesarean delivery for multifetal gestation compared with one previous cesarean delivery for a singleton pregnancy.
METHODS: Patients from the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network Cesarean Registry with one previous cesarean delivery and a current term singleton pregnancy were identified. Cases had one previous cesarean delivery for a multifetal pregnancy. Controls had one previous cesarean delivery for a singleton pregnancy.
RESULTS: Of cases, 556 of 944 (58.9%) attempted a trial of labor. Of controls, 13,923 of 29,329 (47.5%) attempted a trial of labor. The trial of labor success rate was 85.6% among cases and 73.1% among controls (odds ratio 2.19, 95% confidence interval 1.72–2.78). Compared with trial of labor controls, cases had no statistically increased risk of transfusion, endometritis, intensive care unit admissions, uterine rupture, or perinatal complications. Cases in this analysis with a successful trial of labor were more likely to have previously had a successful vaginal birth after cesarean (37.1% compared with 14.1%, P<.001).
CONCLUSION: Women with one previous cesarean delivery for a multifetal gestation have high trial of labor success rates and low complication rates.
LEVEL OF EVIDENCE: II
The frequency of multifetal gestation has increased substantially in the United States, with 3.3% of all births now representing a multifetal birth.1 In addition, the cesarean delivery rate has increased every year since 1996 to a most recently reported rate of 29.1%.2 The enthusiasm for trial of labor seen 10–15 years ago has been tempered by the realization that the procedure can result in complications3 and that the likelihood of a successful trial of labor is related to the indication for the prior cesarean delivery.4 Despite these trends, there are numerous patient subgroups for which insufficient data exist to provide adequate patient counseling. We present data from a large prospectively collected cesarean delivery registry that provides success and maternal-fetal complication rates for women with one prior cesarean delivery for multifetal pregnancy attempting a trial of labor in a subsequent pregnancy.
MATERIALS AND METHODS
The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network performed a prospective 4-year (1999–2002) observational study performed at 19 academic medical centers, initially powered to study trial of labor risks with one compared with more than one prior cesarean deliveries.5 From this data set, pregnant women with a term singleton vertex pregnancy and one previous cesarean delivery were identified. The labor and delivery logbook or database at each participating center was screened daily to identify all cases with a gestational age of 20 weeks or more or delivering an infant of at least 500 g. Data were extracted by medical record review after hospital discharge. Among women whose previous cesarean delivery had been performed in a multiple pregnancy (cases), maternal and perinatal outcomes, as defined in one of the primary analyses,5 were compared between women who attempted a vaginal delivery and those who had an elective repeat cesarean delivery without medical indications (Fig. 1). Among all women attempting a trial of labor, comparisons were made between women who had one previous cesarean delivery for a multiple pregnancy (cases) with a transverse or unknown hysterotomy incision and women who had one previous cesarean delivery for a singleton pregnancy (controls). The original research protocol was approved by institutional review boards at all of the participating centers, and the protocol for this analysis was approved by the Review Board at the University of Utah. Hospital records were reviewed by trained research nurses. Continuous variables were compared using the Wilcoxon rank sum test, and categorical variables were compared using χ2 or Fisher exact test, as appropriate. Logistic regression analyses were performed for vaginal birth after cesarean success rates and peripartum complications, adjusting for age, race or ethnicity, a history of vaginal delivery, and recurring indication for cesarean delivery. Unless otherwise noted, there was less than 5% missing data for all variables. Nominal two-tailed P values are reported with statistical significance defined as P<.05. No adjustments were made for multiple comparisons.
We identified 30,273 well-characterized multiparous women carrying a single fetus, delivering at 37 weeks or later, and with a history of one previous cesarean delivery. Of these, 944 women (3.1%) were identified whose one previous cesarean delivery was for a twin (906), triplet (37), or quadruplet (1) pregnancy. Four hundred twenty were delivered by cesarean for multifetal pregnancy. Among the women whose previous cesarean delivery was for a multiple pregnancy, 556 (58.9%) underwent a trial of labor with a transverse or unknown incision and served as the cases. Three hundred eighty-three did not labor and were delivered by repeat cesarean delivery, defined as either elective (without medical indications, n=205) or indicated (n=178). Among the 29,329 women whose previous cesarean delivery was for a singleton pregnancy, 13,923 (47.5%) underwent a trial of labor with a transverse or unknown incision and served as the control group. Demographic comparisons between the case and control groups are presented in Table 1.
Representative clinical outcomes for the case and control groups are presented in Table 2. Those women whose one prior cesarean delivery was for a multiple pregnancy had higher vaginal delivery rates than did the control women (odds ratio [OR] 2.19, 95% confidence interval [CI] 1.72–2.78) and were at no increased risk of other peripartum complications. Using a refined cohort of those attempting a trial of labor with no history of vaginal delivery (Fig. 2), the rates of success are 74.8% (157 of 210) for the cases and 60.6% (4,341 of 7,168) for the controls (OR 1.93, 95% CI 1.41–2.64) (complete pregnancy histories were unavailable for 58 cases and 972 controls).
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
© 2007 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.
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