Characteristics Associated With Trial Of Labor Among Women With Twin Pregnancies

This study aims to identify patient and health care system factors associated with undergoing trial of labor (TOL) among patients with twin gestations. This is a retrospective cohort study of patients with twin gestations who received care at a large tertiary care center from 2000-2016. Patients with a prior uterine scar or contraindication to vaginal delivery (e.g. monoamniotic gestation or non-cephalic presenting twin) were excluded from analysis. Maternal and clinical characteristics were compared among patients who underwent TOL versus those who did not undergo TOL. Multivariable logistic regression models included characteristics chosen a priori based on clinical experience and those with bivariable associations with p <0.1. An a priori plan was also made to investigate interactions between parity and other factors identified to be significant in the primary models. Of 1,888 eligible patients, 80.7% (N=1524) underwent TOL. Those undergoing TOL were more likely to be younger, multiparous, and have an MFM as the delivering provider (p<0.001). Hypertensive disorders of pregnancy were less prevalent among patients undergoing TOL (20.2% vs. 27.8%, p=0.002). There were no differences in self-identified race/ethnicity or insurance status between comparison groups. In multivariable analysis (Table), advanced maternal age (AMA; aOR 0.55, 95% CI 0.40-0.74) and nulliparity (aOR 0.36, 95% CI 0.25-0.52) conferred a lower odds of TOL, while having an MFM provider (aOR 2.74, 95% CI 1.55-4.83) was associated with higher odds. Interaction analyses demonstrated no significance in interaction effects between parity and other characteristics of TOL. In this cohort with a high rate of TOL for women with twin gestations, patient and provider characteristics are associated with undergoing TOL. These findings suggest that provider comfort with twin vaginal delivery may influence route of delivery decision making in patients with twins. Further investigation is needed to understand how provider experience and counseling impacts patient decision making in this context.