Predictors of in-hospital mortality in newborn conjoined twins

Background: Conjoined twins are rare developmental anomalies. There is a paucity of literature other than case reports and small case series. The aim of this study was to examine national outcomes and identify predictors of mortality in newborn conjoined twins. Methods: We reviewed data on newborn conjoined twins from the Kids' Inpatient Database (1997–2012). Results: A total of 240 patients were identified for a nationally weighted incidence of 1 per 100,000 live births. The majority of conjoined twins were female (n = 190 [81%]). The most commonly associated anomalies were cardiac (n = 87 [36%]), gastrointestinal (n = 41 [17%]), and abdominal wall (n = 32 [13%]) defects. Fifty-six (23%) patients underwent operative procedures, including 28 (12%) neonatal separation surgeries. The overall mortality rate was 61%; most deaths occurred within 24 hours (99 of 146 [68%]) to 48 hours (129 of 146 [88%]) after birth. Mortality was higher in female compared with male children (66% vs 38%, P = .025), premature compared with full-term children (72% vs 44%, P = .007), and in children with extremely low birth weight (95% vs 59%, P = .002). Congenital diaphragmatic hernias were seen in 15 (6%) patients and were uniformly fatal (100% vs 58%, P = .029). Mortality was highest in hospitals not designated as children's hospitals (72%) compared with children's hospitals (44%) (P = .007). Conclusion: Conjoined twins are rare anomalies who are susceptible to extremely high perinatal mortality, especially in female children, those who are premature, or those who have low birth weight. These data support caring for these complex patients at hospitals equipped to care for this fragile population.