Objective: Eisenmenger syndrome (ES) is regarded as a contraindication to pregnancy, with therapeutic abortion recommended in the event of unintended pregnancy. However, women with ES continue to desire and attempt pregnancy despite grave risks to their own health. This study compares the costs and outcomes of pregnancy in women with ES to the use of gestational surrogates in their pregnancies. Study design: A decision-analytic model was built using TreeAge software that compared use of gestational surrogates and pregnancy in women with ES. Maternal death and neonatal outcomes including intrauterine fetal demise, preterm birth, cerebral palsy, and death were assessed. All probabilities and costs were derived from the literature. Utilities were discounted at a rate of 3% across the expected lifespan to generate quality-adjusted life years (QALYs). Univariate and multivariate sensitivity analyses were performed to evaluate the robustness of the model given changes in baseline assumptions. Results: In a theoretical cohort of 1000 women with ES, pregnancy would result in 360 maternal deaths, 100 stillbirths, 477 preterm births, and 157 neonatal deaths. In these highly desired pregnancies, use of gestational surrogates would prevent 99 and 98% of maternal and neonatal death, respectively. Cases and costs of preterm birth and associated cerebral palsy are also significantly reduced. Use of a gestational surrogate would save $518,255 per woman with a gain of 6.77 QALYs, a dominant strategy. The approach is cost-effective up to a cost of surrogacy of $1.2 million and even if the surrogate achieves pregnancy only 30% of the time. Conclusions: The use of surrogate mothers for those with ES is cost-effective and results in significantly improved maternal and neonatal outcomes. These benefits are robust in the face of high surrogacy costs largely due to the marked reduction in maternal mortality and preterm birth. These findings should be used to underscore the importance of broadening health care financing for medically-indicated assisted reproduction.