Brief communication

Successful pregnancy following modified Fontan procedure in a patient with tricuspid atresia and recurrent atrial flutter

Women with single ventricle cardiac physiologic condition who have undergone Fontan procedures are surviving well into reproductive age and historically have been discouraged from pregnancy, despite the paucity of data regarding maternal and neonatal outcomes.

Our primary objective was to investigate, in a large cohort, the maternal and neonatal outcomes of pregnant women who have undergone the Fontan procedure and to understand maternal and neonatal sequelae of their pregnancies.

This single-center retrospective cohort study involves pregnant women with a Fontan palliation who delivered at UCLA Medical Center over a 10-year period (2007–2017). All pregnancies were evaluated for differences in maternal and neonatal characteristics.

We identified 37 distinct pregnancies in 24 women with a Fontan procedure. The physiologic pregnancy-related increase in cardiac output is blunted substantially in Fontan circulation. Third-trimester cardiac index positively correlated to birthweight z-score (R²=0.48; P=.038) but not to small for gestational age (R²=0.13; P=.339). The most common cardiac complications in pregnancies of >24 weeks gestation were sustained arrhythmia (37.5%) and decompensated heart failure (21%). The 37 pregnancies comprised 25 live births (67.6%), 1 fetal death (2.7%), 9 spontaneous abortions (24%), and 2 pregnancy terminations (5.4%). Of the live births, 60% were preterm at an average gestational age of 34.9±3.7 weeks. Newborn infants were delivered via cesarean in 53%, operative vaginal delivery in 28%, and spontaneous vaginal delivery in 20%. Forty percent of neonates were born small (<10th percentile) for gestational age; 44.0% of all neonates were admitted to the neonatal intensive care unit.

Women with a single ventricle and Fontan circulation can have a successful pregnancy, although they are at increased risk for arrhythmias and heart failure. The decreased cardiac reserve in these pregnancies blunts the normal increase in maternal cardiac output, which is associated with preterm delivery and small-for-gestational-age neonates. Further studies are needed to determine to what extent the impaired rise in maternal cardiac output reduces uteroplacental perfusion, placental exchange, fetal growth, and onset of parturition.

Women with cyanotic congenital heart disease with reduced cardiac reserve have decreased ability to tolerate the cardiovascular demands of pregnancy, labor and delivery and to accommodate pregnancy complications, such as preeclampsia and hemorrhage. The most commonly encountered congenital cyanotic heart disorder is tetralogy of Fallot. Unoperated women with this disorder have a mortality rate of 3–12% and a high rate of perinatal loss, but pregnancy outcomes in women who have had complete repairs are nearly the same as for the normal population. The 30% maternal mortality rate in Eisenmenger syndrome is largely due to the inability of the relatively fixed pulmonary vascular resistance to adjust to the cardiovascular demands of pregnancy, delivery and the puerperium. Inhaled local vasodilators, such as nitric oxide or aerosolized prostacyclin, show promise in the treatment of pulmonary hypertension and right heart failure in this disorder. The atrial switch repair for dextro-transposition of the great arteries, which can be associated with functional deterioration in the systemic morphologic right ventricle, generally results in good outcome for the mother and fetus. The Fontan repair for complex cyanotic congenital heart disease with single-ventricle physiology has also been associated with good pregnancy outcome, although the spontaneous abortion rate may increase. Cervical ripening techniques, carefully titrated neuraxial anesthesia, and pulse oximetry have made labor and delivery safer for women with unrepaired or palliated cyanotic heart disease or repaired disorders with residual cyanosis. Pregnancy outcomes in women with high-risk but low-prevalence cardiac conditions would likely be improved further if a national registry to assess standardized management was established.

The univentricular heart is a rare form of congenital cardiac disease. We report the successful management of a parturient with a single ventricle, transposition of the great arteries, pulmonary hypertension and thrombosis of the superior vena cava. The univentricular heart is discussed in detail and the outcome in other mothers with similar cardiac anomalies is reviewed.

Objectives. This study sought to determine risks and outcome of pregnancy and delivery after the modified Fontan operation.

Background. Increasingly, female Fontan patients reaching child-bearing years are interested in having children. To date, the number of reported pregnancies is small, and pregnancy has therefore been discouraged.

Methods. One hundred ten of 126 female patients from the Fontan registries of the Mayo Clinic and University of California Los Angeles Medical Center responded to a mailed questionnaire. An additional six patients with a reported pregnancy from other centers were identified and reviewed to assess pregnancy outcomes.

Results. Among the participating centers, a total of 33 pregnancies after Fontan operation for various types of univentricular heart disease were reported. There were 15 (45%) live births from 14 mothers, with 13 spontaneous abortions and 5 elective terminations. In the 14 women with live births, the median number of years between operation and pregnancy was 4 (range 2 to 14). Reported prepregnancy problems in these gravidas included atrial flutter in one patient and ventricular dysfunction, aortic regurgitation and atrioventricular valve regurgitation in another. One patient developed supraventricular tachycardia during pregnancy and had conversion to sinus rhythm. No maternal cardiac complications were reported during labor, delivery or the immediate puerperium. There were six female and nine male infants (mean gestational age 36.5 weeks; median weight 2,344 g). One infant had an atrial septal defect. At follow-up, mothers and infants were alive and well.

Conclusions. Pregnancy after the Fontan operation appears to have been well tolerated in 13 of 14 gravidas. There does appear to be an increased risk of miscarriage. The tendency to routinely discourage pregnancy may need to be reconsidered.