Mode of Obstetric Delivery in Kidney and Liver Transplant Recipients and Associated Maternal, Neonatal, and Graft Morbidity During 5 Decades of Clinical Practice.

Importance: Rates of cesarean delivery (CD) are increased among transplant recipients. There is a need to define the indications for CD and associated outcomes among transplant recipients to determine the safest mode of obstetric delivery. Objective: To evaluate the association of mode of obstetrical delivery with maternal and neonatal morbidity among pregnant women who have received a kidney or liver transplant. Design, Setting, and Participants: This registry-based retrospective cohort study used data from the Transplant Pregnancy Registry International, which has recruited participants since 1991 from 289 diverse academic and community settings, mainly in North America. Eligible participants were recipients of a kidney or liver transplant who were aged 18 years or older at the time of a live birth at or later than 20 weeks' gestational age and who delivered between 1968 and 2019. The data were analyzed from April 30, 2020, to April 16, 2021. Exposures: Scheduled CD, a trial of labor resulting in CD (TOL-CD), or a TOL resulting in vaginal delivery (TOL-VD). Main Outcomes and Measures: The primary outcomes were severe maternal morbidity and neonatal composite morbidity. Multivariate regression was conducted to calculate odds ratios (ORs) or β values and 95% CIs with adjustment for differences in maternal comorbidities and gestational age at delivery. Nonmedical indications for CD are those not associated with decreased morbidity or mortality in the obstetric literature. Results: This study included 1865 women, of whom 1435 were kidney transplant recipients and 430 were liver transplant recipients. The age range of the participants was 18 to 48 years; the median body mass index among the participants was in the normal range, and the median transplant-to-conception interval was more than 2 years. Compared with a scheduled CD, a TOL was not associated with increased severe maternal morbidity among kidney transplant recipients (TOL-CD: adjusted odds ratio [aOR], 1.80 [95% CI, 0.77-4.22]; TOL-VD: aOR, 1.22 [95% CI, 0.57-2.62]) (for liver transplant recipients, the numbers were too small for multivariate modeling). In the adjusted model, a TOL was associated with a decrease in neonatal composite morbidity among kidney transplant recipients who underwent TOL-CD (aOR, 0.52; 95% CI, 0.32-0.82) and TOL-VD (aOR, 0.36; 95% CI, 0.24-0.53) and liver transplant recipients who underwent TOL-VD (aOR, 0.41; 95% CI, 0.19-0.87) but not for TOL-CD (aOR, 0.58; 95% CI, 0.21-1.61). The main factors associated with CD after labor were placental abruption (aOR, 12.96; 95% CI, 2.85-59.07) and pregestational diabetes (aOR 5.44; 95% CI, 2.54-11.68). The rate of CD was 51.6% (741 of 1435) among kidney transplant recipients and 41.4% (178 of 430) among liver transplant recipients. In total, 229 of 459 kidney transplant recipients (49.9%) and 50 of 105 liver transplant recipients (47.6%) had scheduled CDs performed for either a nonmedical indication or a repeated indication, although women with these indications are candidates for a TOL. Conclusions and Relevance: In this cohort study, TOL vs a scheduled CD was associated with improved neonatal outcomes among kidney and transplant recipients and not with increased severe maternal morbidity among kidney transplant recipients. These findings may be used to facilitate multidisciplinary decisions regarding the mode of obstetrical delivery.