Prenatal diagnosis of congenital heart defects: experience of the first Fetal Cardiology Unit in Mexico.

OBJECTIVE: The purpose of this article was to describe our experience with the prenatal diagnosis of CHD in patients referred to our Fetal Cardiology Unit. METHODS: Prospective cohort study of consecutive fetuses referred for advanced fetal echocardiography to our Fetal Cardiology Unit during a 3-year period (September 2015-September 2018). RESULTS: Totally 809 fetuses were evaluated, with 1263 fetal advanced echocardiographies performed. Suspected cardiac abnormality was the most common indication for referral (62.2%). Only 7.3% of patients had known morbidities or risk factors for CHD. Mean gestational age at first examination was 25.6 ± 6.4 weeks. A total of 528 (65.3%) fetuses were found to have a cardiac defect: 40.7% had isolated CHD while 24.6% had associated anomalies. The most common defects found were ventricular septal defects (20.3%), followed by conotruncal defects (9.7%), hypoplastic left heart syndrome (9.3%), fetal arrhythmias (8.9%), and venous anomalies (8.7%). 31.6% presented abnormal genetic studies, the most frequent being Down syndrome (23/212, 10.8%), followed by DiGeorge syndrome (11/212, 5.2%). CONCLUSIONS: Prenatal screening and diagnosis of CHD in Mexico are feasible, with suspected cardiac abnormality being the main reason for referral to a specialized Fetal Cardiology Unit. Efforts must be made to make screening available to the general population in the first and second trimesters of pregnancy by fetal medicine or trained specialists, in order to identify fetal CHD and offer advanced echocardiography, genetic studies, timely fetal cardiac intervention in selected cases, and delivery in tertiary centers, to improve overall survival.

Outcomes of hypoplastic left heart syndrome and fetal aortic valvuloplasty in a country with suboptimal postnatal management.

BACKGROUND: Fetal aortic stenosis (AoS) may progress to hypoplastic left heart syndrome (HLHS) in utero. There are currently no data, prenatal or postnatal, describing survival of fetuses or neonates with AoS or HLHS in a country with suboptimal postnatal management. STUDY DESIGN: Prospective cohort study performed in Mexico, including cases diagnosed with AoS and HLHS within a 6-year period. AoS patients fulfilling previously published criteria for evolving HLHS (eHLHS) were offered fetal aortic valvuloplasty. Outcome variables were perinatal mortality, postnatal management, type of postnatal circulation, and overall survival. RESULTS: Fifty-four patients were included: 16 AoS and 38 HLHS. Eighteen patients had associated anomalies and/or an abnormal karyotype. Seventy-four percent of HLHS received comfort measures, with only three cases reporting an attempt at surgical palliation, and one survivor of the first stage. Fetal aortic valvuloplasty was performed successfully in nine cases of eHLHS. Overall postnatal survival was 44% in AoS with fetal aortic valvuloplasty, and one case (ongoing) in the HLHS group. CONCLUSIONS: HLHS in Mexico carries more than a 95% risk of postnatal death, with little or no experience at surgical palliation in most centers. Fetal aortic valvuloplasty in AoS may prevent progression to HLHS and in this small cohort was associated with ≈50% survival.

A multicentre study to predict neonatal survival according to lung-to-head ratio and liver herniation in fetuses with left congenital diaphragmatic hernia (CDH): Hidden mortality from the Latin American CDH Study Group Registry.

OBJECTIVE: To evaluate natural history of fetuses congenital diaphragmatic hernia (CDH) prenatally diagnosed in countries where termination of pregnancy is not legally allowed and to predict neonatal survival according to lung area and liver herniation. METHODS: Prospective study including antenatally diagnosed CDH cases managed expectantly during pregnancy in six tertiary Latin American centres. The contribution of the observed/expected lung-to-head ratio (O/E-LHR) and liver herniation in predicting neonatal survival was assessed. RESULTS: From the total population of 380 CDH cases, 144 isolated fetuses were selected showing an overall survival rate of 31.9% (46/144). Survivors showed significantly higher O/E-LHR (56.5% vs 34.9%; P < .001), lower proportion of liver herniation (34.8% vs 80.6%, P < .001), and higher gestational age at birth (37.8 vs 36.2 weeks, P < 0.01) than nonsurvivors. Fetuses with an O/E-LHR less than 35% showed a 3.4% of survival; those with an O/E-LHR between 35% and 45% showed 28% of survival with liver up and 50% with liver down; those with an O/E-LHR greater than 45% showed 50% of survival rate with liver up and 76.9% with liver down. CONCLUSIONS: Neonatal mortality in CDH is higher in Latin American countries. The category of lung hypoplasia should be classified according to the survival rates in our Latin American CDH registry.

Longitudinal changes in lung size and intrapulmonary-artery Doppler during the second half of pregnancy in fetuses with congenital diaphragmatic hernia.

OBJECTIVES: The objectives of the study are to evaluate longitudinal changes in lung size and intrapulmonary-artery (IPa) Doppler in fetuses with congenital diaphragmatic hernia (CDH) and assess their contribution in predicting neonatal survival. METHODS: The observed/expected lung-to-head ratio (O/E-LHR) and IPa-pulsatility index (PI) and peak early diastolic reversed flow (PEDRF) were evaluated in a cohort of left-sided CDH fetuses managed expectantly during pregnancy. Longitudinal changes were analyzed by multilevel analysis, and their value to predict survival using the multiple logistic regression and decision-tree analysis was assessed. RESULTS: A total of 232 scans were performed on 69 CDH fetuses. The O/E-LHR values remained unchanged during fetal monitoring, whereas IPa-PI and PEDRF showed a progressive increase throughout follow-up, becoming abnormal on average at 30 weeks of gestation. Absent/reversed end-diastolic velocity (EDV) in the IPa was observed in 20.3%. O/E-LHR and IPa Doppler indices were significantly associated with probability of survival (O/E-LHR ≥ 26%, odds ratio [OR] 19.0; IPa-PI <+2.0 z score, OR 3.0; and positive EDV, OR 7.4). All cases with IPa-reversed EDV died after birth. CONCLUSION: While lung size remains stable during pregnancy, CDH fetuses show progressive deterioration in intrapulmonary blood flow. IPa Doppler evaluation may aid in predicting survival of CDH fetuses managed expectantly during pregnancy.

Thoracic Changes after Full Laser Ablation of the Feeding Artery in Fetuses with Bronchopulmonary Sequestration.

OBJECTIVE: To assess longitudinal intrathoracic changes after fetal laser surgery in fetuses with bronchopulmonary sequestration (BPS) with hydrops and/or hydrothorax. STUDY DESIGN: The presence of intrafetal fluid effusions, the lung mass volume ratio (congenital pulmonary airway malformation volume ratio [CVR]), and the observed/expected lung-to-head circumference ratio (O/E-LHR) of both lungs were evaluated in a cohort of BPS fetuses with hydrops and/or hydrothorax treated with full laser ablation of the feeding artery (FLAFA). The longitudinal changes in intrafetal fluid effusions, lung mass volume, and pulmonary growth were analyzed by survival and multilevel analysis against days after FLAFA. RESULTS: FLAFA was successfully performed in 15 cases at a median gestational age of 26.9 weeks. A complete disappearance of the hydrops and hydrothorax was observed a median interval of 7.5 and 21 days after the fetal intervention, respectively. A progressive decrease in the CVR and an increment in the size of both lungs were observed after FLAFA. The O/E-LHR of the lung contralateral and ipsilateral to the side of the BPS became normal on average 8 and 10 weeks after FLAFA, respectively. CONCLUSION: Fetal laser surgery with FLAFA promotes disappearance of all fetal fluid effusions, a lung mass regression sequence, and a normalization of pulmonary growth.