ABC | Volume 113, Nº6, December 2019

Original Article Avila et al. Pregnancy and complex congenital heart disease Arq Bras Cardiol. 2019; 113(6):1062-1069 Postpartum hemorrhage, the reason for the second death in our study, is considered an important obstetric cause of maternal death in women with heart disease, especially in hypoxemic patients. This fact was documented in a study of 366 primiparous women with congenital heart diseases, which recorded 21% of postpartum hemorrhage. That study identified early Caesarean section, general anesthesia and use of low‑molecular-weight heparin at both prophylactic and therapeutic doses, as variables of higher correlation with postpartum bleeding. Furthermore, women with Fontan circulation had the highest blood loss and the difference remained significant after correcting for the other variables. 11 In our study, the association of hypoxemia and postpartum hemorrhage associated with Caesarian delivery resulted in the second maternal death. Actually, the highest maternal and fetal morbidities associated with premature Caesarean delivery is due to maternal clinical instability and intrauterine growth restriction, common in complex heart situations. A brief emphasis should be placed on the most common heart disease in this cohort, such as the transposition of the great arteries and the Fontan circulation. The promising evolution after the correction of the transposition of the great arteries through atrial inversion (Senning’s procedure or Mustard’s technique) or arterial inversion (Jatene’s technique) has allowed the development of pregnancy. 12,13 However, there are expected events in the late postoperative period that may be unfavorable to the success of pregnancy. Supraventricular arrhythmias and ventricular dysfunction in adulthood may occur in about 40% of patients after surgical correction using Mustard’s technique or Senning’s procedure. On the other hand, neo-aortic valve regurgitation, present in 1-2% and coronary complications observed in 3-11% of cases, may both occur in the long term after Jatene’s technique. Regarding Rastelli's surgery, the late evolution depends on the type of tissue used, which can determine different degrees of calcification and progressive occlusion of the graft. 14 Based on these considerations, during pregnancy, one must be prepared for the treatment of heart failure and arrhythmias when there is right ventricular dysfunction and tricuspid regurgitation after Mustard’s and Senning’s techniques; heart failure and low output due to calcified conduits after the Rastelli procedure, of valve dysfunctions and/or coronary complications, when Jatene’s technique had been used. 14 This study showed that, with the exception of one patient who was not operated whose pregnancy ended in miscarriage (case 12), the other pregnant women with transposition of the great vessels of the base showed favorable maternal and fetal evolutions, regardless of the type of surgical correction. It is worth emphasizing that the expected complications were controlled with hospitalization and constant monitoring of the mother and fetus. Fontan circulation has allowed the survival of 70% of the patients with univentricular heart disease up to childbearing age. 15 However, in the late postoperative period, complications such as atrial tachycardia, thromboembolism (related to hepatic and venous system stasis), heart failure, liver failure and, protein-losing enteropathy. The abnormal connection - vena cava and pulmonary circulation – despite the improvement in cyanosis, ventricular overload reserve and pulmonary circulation capacity, may be threatened by the variations in the central venous pressure and by the negative intrathoracic pressure induced by hyperventilation and changes in cardiac output during pregnancy. The inability of patients with Fontan circulation to adapt to physiology of the pregnancy and postpartum period was documented in our study that showed worsening of the functional class in all the patients. Heart failure occurs because the abnormal anatomical and functional ventricle is unable to adjust to the increased cardiac output. However, there was no maternal death due to a good responses were obtained to the clinical treatment with the use of diuretic and beta-blocker in patients who developed heart failure (cases 15 and 41), and to electric cardioversion in case of atrial flutter (case 21). On the other hand, the evolution unfavorable to the fetus was documented in six Fontan cases, resulting in a miscarriage and five premature deliveries. Review of the literature that included six studies with 255 pregnancies and 133 women showed 137 (69%) fetal loss, and 68 (59%) of the 115 live newborns were premature and six (5,2%) evolved to neonatal death. The causes of prematurity were not detailed, particularly in those induced by the anticipation of the delivery due to maternal reasons. However, the premature rupture of the amniotic membranes and placental premature detachment occurred in 6.2% and 10.9%, respectively. 16 The poor fetal prognosis was confirmed by the multicenter study of the United Kingdom that included 50 women, 124 pregnancies, showed an incidence of 68 (54.8%) miscarriages and, among the 56 (45.2%) live newborns, four died due to extreme prematurity (delivery with gestational age below 32 weeks). On the other hand, the maternal complications (heart failure in 13.5%, arrhythmias in 11.3% and pulmonary thromboembolism in 1.19% of the cases) do not result in maternal death. 17 The full anticoagulation routine in patients with Fontan circulation should be considered by reasons of the high risk of thromboembolismpeculiar to this setting and the hypercoagulable state of the pregnancy and postpartum. This present study showed three cases of maternal thromboembolism, two of which were in a non-anticoagulated patient. Patients with Fontan circulation should advise against pregnancy specially in patients with depressed ventricular function, cyanosis, important mitral valve insufficiency or protein-losing enteropathy. 15-17 This study showed that hypoxemia was the presumable variables of the worst maternal-fetal prognosis, as previous report. 18 The unusual result of the previous surgical correction did not show any difference in the evolution of the pregnancy, possibly was related to a small number of the cases and some cases had cardiac lesion with an anatomy favorable to survival during childbearing age. Therefore, another study that analyzed 102 necropsies of congenital heart failure patients verified that the average age of cases not operated was higher than those operated and presented also less serious anatomical defects. 9 Another highlight of our study is the record of two newborns (5%) with of congenital heart disease which equivalent to six times more than the 0.8% estimated for the general 1067