Delivery trends and obstetric outcomes in patients with Fontan circulation

With improved therapies, an increasing number of patients with Fontan circulation reach reproductive age. Pregnant patients with Fontan circulation are at high risk of obstetrical complications. Most data for pregnancies complicated by Fontan circulation and associated complications stem from single-center studies, with limited national epidemiologic data available.

This study aimed to evaluate temporal trends in deliveries to pregnant individuals with Fontan palliation using nationwide data and to estimate associated obstetrical complications among these deliveries.

Delivery hospitalizations were abstracted from the 2000 to 2018 Nationwide Inpatient Sample. Deliveries complicated by Fontan circulation were identified using diagnosis codes, and trends in the rates of these deliveries were assessed using joinpoint regression. Baseline demographics and obstetrical outcomes (including severe maternal morbidity, a composite of serious obstetrical and cardiac complications) were assessed. Univariable log-linear regression models were fit comparing risks of outcomes among deliveries of patients with and without Fontan circulation.

A total of 509 pregnancies complicated by Fontan circulation were identified at a rate of 7 per 1 million delivery hospitalizations, with a temporal increase from 2.4 to 30.3 cases per 1 million from 2000 to 2018 (P<.01). Deliveries complicated by Fontan circulation were at higher risk of hypertensive disorders (relative risk, 1.79; 95% confidence interval, 1.42-2.27), preterm delivery (relative risk, 2.37; 95% confidence interval, 1.90-2.96), postpartum hemorrhage (relative risk, 4.28; 95% confidence interval, 3.35-5.45), and severe maternal morbidity (relative risk, 6.09; 95% confidence interval, 4.54-8.17) than deliveries not complicated by Fontan circulation.

The rates of deliveries of patients with Fontan palliation are increasing on a national level. These deliveries have higher risks of obstetrical complications and severe maternal morbidity. Additional national clinical data are necessary to better understand the complications in pregnancies complicated by Fontan circulation, to improve patient counseling, and to reduce maternal morbidity.