Objective There is growing evidence that maternal mortality in pregnant women with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is lower than that in available data. In order to evaluate this hypothesis, we collected data of pregnancies in women with PAH-CHD.

Methods Women with PAH-CHD followed in seven French referral centres were retrospectively included from 1997 to 2015. All pregnancies were recorded. We collected data on maternal, obstetrical and neonatal outcomes.

Results 28 pregnancies in 20 women (26±6 years old) with PAH-CHD were managed during this period. There were 18 complete pregnancies (≥20 weeks’ gestation (WG)), 8 abortions and 2 miscarriages. Six (33%, 95% CI (11.9 to 54.3)) patients experienced severe cardiac events. The concerned women had lower resting oxygen saturation (79.6±4.1% vs 89.3±3.8%, p<0.01). The most common cardiac complications during the complete pregnancies were heart failure (n=4) and severe hypoxaemia (n=5). Heart failure was overall severe, requiring inotropic treatment in three patients, mechanical circulatory support in one and led to one maternal death (mortality=5.0% 95% CI (0.1 to 24.9)). Obstetrical complications occurred in 25% of pregnancies. Small for gestational age was diagnosed in 39% (7/18) of fetuses. 12/18 (67%) pregnancies were delivered by caesarean section, of which 10 in emergency for obstetrical reason. Prematurity was frequent (78%), but no neonatal death occurred.

Conclusions Outcome of pregnancy in women with PAH-CHD is better than previously reported, with only 5% maternal mortality in our cohort. However, because of the severity of heart failure and the high rate of neonatal complications, patients should still be advised against pregnancy.