Heart Transplant and Pregnancy: Evaluating the Role of Preeclampsia in Maternal, Neonatal, and Graft Morbidity.

Background: Heart transplant recipients (HTRs) during pregnancy are at greater risk for maternal and obstetrical complications and hypertensive disease of pregnancy exacerbates these risks. The impact of preeclampsia on HTRs is unknown.

Objectives: The authors describe characteristics of HTRs who developed preeclampsia and the effect of preeclampsia on graft and pregnancy outcomes.

Methods: This is a retrospective group study of adult HTRs with subsequent pregnancy outcomes of ≥20 weeks' gestation enrolled in the Transplant Pregnancy Registry International between 1986 and 2022. The primary outcome was graft loss within 2 years from delivery. Secondary outcomes included maternal and neonatal outcomes.

Results: A total of 146 pregnancies and 149 neonates met inclusion criteria. All were livebirths. Forty-two pregnancies (28.8%) were complicated by preeclampsia. HTRs in the preeclampsia group were more likely to be nulliparous (81.0% vs 54.8%; P < 0.01), and have chronic hypertension (73.8% vs 34.6%; P < 0.01). There was no difference in incidence of graft loss at 2 years with (4.8%) or without (2.9%) preeclampsia (P = 0.72). There was no clinically important difference in graft survival in pregnancies with preeclampsia compared with pregnancies without preeclampsia (adjusted HR: 0.79 [95% CI: 0.37-1.69]; P = 0.54). However, rates of severe maternal morbidity were high in both groups: 16.7% in the preeclampsia group and 10.6% in those without preeclampsia. Furthermore, preeclampsia was associated with earlier gestational age at birth (35.0 vs 37.0 weeks; P < 0.01) and lower birth weight (2,310 vs 2,801 grams; P < 0.01).

Conclusions: There was no difference in graft loss from delivery in HTRs who developed preeclampsia during pregnancy. Regardless of preeclampsia, pregnant HTRs are more likely than the general population to experience severe maternal morbidity. These findings provide pertinent information for counseling heart transplant recipients who pursue pregnancy.