Poster Session I Thursday, February 1 • 10:30 AM - 12:00 PM • Trinity Exhibit Hall| Volume 218, ISSUE 1, SUPPLEMENT , S148, January 2018

226: TOLAC success in twin pregnancies in the United States (2013-2015)


      Robust data about the likelihood of successful trial of labor after cesarean delivery (TOLAC) exists for women with singleton pregnancies. We aimed to determine the success of TOLAC in twin pregnancies in the United States between 2013 and 2015.

      Study Design

      This is a population-based analysis of the TOLAC success rate in twin pregnancies in the United States. We used “Natality” files from the National Center for Health Statistics for 2013-2015. All women with twin gestations who attempted a TOLAC were included in this study. The primary outcome was the mode of delivery and was calculated based on birth certificate data. Multivariable regression analysis was performed to test the effect of age, body mass index, African American race, Hispanic ethnicity, and number of previous cesarean deliveries on likelihood of successful TOLAC. History of prior TOLAC and prior vaginal delivery were not available. Statistical analysis was performed using R-3.4.1.


      Out of 380,095 total twin births, 60,845 (16.0%) had history of previous cesarean delivery (CD); 42,332 (11.1%) and 13,898 (3.7%) were to mothers with history of one (CD1) and two (CD2) previous CDs, respectively. TOLAC was attempted in 7,570 (12.4%) women [4138 (9.7%) of CD1 versus 713 (5.1%) of CD2]. and was successful in 2437 (47%) of cases [2112 (51%) of CD1 versus 239 (33.5%) of CD2, (P < 0.001)]. Multivariable regression analysis revealed no association between age, African American race, Hispanic ethnicity and number of previous cesarean deliveries with a successful TOLAC (Table).


      Compared to TOLAC success rates in the medical literature for singleton gestations, the overall likelihood of successful TOLAC appears to be lower in twin pregnancies, specifically in women with 2 prior cesarean deliveries. Since primary CD rates of up to 50% are quoted to exist for twins, factors beyond those proposed to affect the likelihood of successful TOLAC in singleton gestations may play a role in twin gestations. A significant number of women who attempt TOLAC with twins will deliver vaginally, however appropriate counseling is warranted.
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