Tetralogy of Fallot (TOF) is a type of congenital heart disease (CHD) in which possesses the hemodynamic alterations characteristic of morphologic pulmonary arterial abnormality, ventricular dysfunction, right ventricular systolic dysfunction, right ventricular dilation, outflow tract obstruction, pulmonary hypertension. After corrective surgery, the majority of young women with TOF survive into their reproductive age. But it is generally known that heart disease constitutes a leading nonobstetric cause of maternal mortality，especially in patients with those cyanotic and complex shunt lesions. Previous studies on pregnant women with TOF showed that pregnancy carries a considerable risk to the women’s status, and the adverse cardiovascular events may be associated with right ventricular dysfunction, severe pulmonary hypertension, and severe pulmonic regurgitation with RV dysfunction[10,11]. Right ventricular function parameters with abnormal uteroplacental Doppler flow (UDF) suggests that cardiac dysfunction contributes to defective placentation or placental perfusion mismatch and may explain the increased incidence of obstetric and neonatal complications.
In the past decades, CHD patients are increasingly reaching adulthood owing to remarkable diagnostic and therapeutic approaches. But TOF as serious complex and cyanotic congenital heart disease, women with uncorrected defects rarely survive into childbearing age and pregnancy. Some women with uncorrect TOF indeed successfully got pregnancy. However, because of the small number of these cases, the outcomes in these patients are not well studied, though it commonly thought that pregnancy adds extra load on the heart, and can damage cardiac function in a manner that leads both to increased maternal and perinatal morbidity[1–3,7]. In the current study, right ventricle dilation were found in all the patients without uncorrected TOF but present in less than half patients with corrected TOF. No incidence of thromboembolism and endocarditis were found in studied subjects, which may explain the overall good clinical outcomes in spite of different degrees of arrhythmias. Women with NYHA class > III have a relatively poor prognosis during pregnancy. Of note, one uncorrected patient with NYHA class IV was the only patient with limited left ventricular systolic function and pulmonary arterial hypertension. This patient had to terminate pregnancy at 27+6 weeks due to ventricular failure. She survived with careful care, but the baby died at the post-partum period (the 7th day after birth). These results suggest that the degree of right ventricle dilation and NYHA classification are the most relevant factors for negative outcomes.
In the literature, it has been demonstrated that patients with corrected TOF still have a higher risk a poor pregnancy outcome because of the haemodynamic burden of pregnancy combined with residual cardiovascular lesions after repair[13,14]. Further problems after repair include residual or recurrent right ventricular outflow obstruction, right ventricular dilatation and residual VSD; and pulmonary regurgitation may lead to right ventricular dilatation and failure, atrial and ventricular arrhythmia, reduced exercise capacity. In our study, there was residual shunt at VSD patches in 2 patients whose NYHA class all were grade III in the corrected group. And 6 patients (31.58%) had pulmonary regurgitation and about two-thirds of patients have different degrees of arrhythmia. Fortunately, none of our patients with corrected TOF showed pulmonary arterial hypertension and limited left ventricular systolic function. Following the surgical repair, electrocardiogram returned to normal in 5 patients (26.32%), and the right ventricle diameter and NYHA class were in normal range in more than half of them. Overall, women of childbearing age with repaired TOF may have lower pregnancy-related risks than those who did not undergoing pregnancy; the changes in ventricle dimensions and NYHA class are consistent with normal pregnancy adaptation.
Maternal condition and mortality has significant effects on fetal outcome in CHD patients. Pregnant women with TOF were at high risk for maternal and neonatal complications as other types of heart disease, involving miscarriage, prematurity, premature rupture of membranes (PROM), preeclampsia, breech presentation, postpartum hemorrhage for the mothers; and small for gestational age, low birth weights, and cardiac anomalies for the newborns[4,18].Recently，Ramage et al. reported 2114 births to women with ACHD ( adult congenital heart disease) and suggested an association between several adverse neonatal and maternal outcomes and ACHD.They results showed that preterm births (<37 weeks gestation) were associated with 1.4 times higher odds among women with ACHD compared with those without ACHD.Women with ACHD also had higher odds of having a preterm birth at less than 32 weeks’gestation. Almost 12.8% of women with ACHD delivered an SGA infant compared with 8.7% of women without ACHD. Similar to the results of this study, all the patients in our study have survived although most all of them suffered varying degrees of cardiac and obstetric complications, and the complications were more frequent in the uncorrected group. In addition, the rate of prematurity, miscarriage and SGA was significantly higher in the uncorrected group. There is a 50% incidence of prematurity in the uncorrected patients. Due to low maternal cardiac output, intrauterine growth restriction may unavoidably occur. The mean birth weight centile was significantly lower, and the small for gestational age was a common occurrence (41.67%) in pregnancy women with unrepaired TOF. In consideration of high complication risks, woman with cardiac disease may be safer with a cesarean section delivery to avoid prolonged labor or any pushing.In this study, one patient with intrauterine fetal death undergone transvaginal complete curettage of uterine cavity, other uncorrected patients delivered by cesarean section under combined spinal epidural anesthesia, epidural anesthesia or general anesthesia. We assumed that the successful outcomes resulted from the absence of thromboembolism, severe hypertension, and cardiac failure. Although one case suffered with hypertension and cardiac failure, she was survived with professional care. Women at highest risk can benefit from preconception counseling and close clinical monitoring during pregnancy. Careful interdisciplinary management among the cardiologist, obstetrician, anesthetist, and neonatologist, and detailed plans for delivery may have improved the prognosis.