Analysis on echocardiographic data of fetal heart defects at high altitude in Yunnan province and surrounding high altitude areas

Abstract

Objective: To explore the current situation of fetal heart defects in Yunnan Province and surrounding high altitude areas and the social factors affecting pregnancy outcome. Methods: This is a retrospective study. Pregnant woman who underwent fetal echocardiography and diagnosed as fetal cardiac defects in Yunnan Fuwai Cardiovascular Hospital from June 2017 to January 2021 were included. According to the clinical prognostic risk scoring system and grading criteria of fetal cardiac birth defects, the cases were divided into grade Ⅰ to Ⅳ. The disease distribution and proportion of each prognostic grade, pregnancy outcomes were analyzed and compared. The cases were divided into continued pregnancy group and terminated pregnancy group according to pregnancy outcome. The social factors that may affect the selection of pregnancy outcomes were analyzed by multivariate logistic regression analysis. Results: A total of 4 929 fetal echocardiography examination data were collected, and 4 464 cases (90.57%) were from Yunnan Province and surrounding high altitude areas. 2 166 cases of heart defects were finally analyzed, including 998 cases of congenital heart disease (CHD), 93 cases of cardiac tumors, cardiomyopathy and arrhythmia, 1 075 cases of foramen ovale, ductus arteriosus abnormalities and normal variations. The pregnant women were (29.2±5.0) years old with (25.6±3.8) gestational weeks. The number of cases with prognostic grade from Ⅰ to Ⅳ was 1 037 (47.88%), 620 (28.62%), 314 (14.50%), and 44 (2.03%), respectively. And 151 cases (6.97%) were not classified. The cases of normal variation and thin aortic arch development accounted for 42.66% (924/2 166), 5.22% (113/2 166), respectively. The top 3 diseases of grade Ⅱ were ventricular septal defect, coarctation of aorta and mild-moderate pulmonary stenosis, respectively, and their distribution was 11.63% (252/2 166), 3.92% (85/2 166) and 2.35% (51/2 166) respectively in all cases of heart defects, and 25.25% (252/998), 8.52% (85/998) and 5.11% (51/998) respectively in cases of CHD. Among the cases rated as grade Ⅲ and Ⅳ, most of them were complicated congenital heart disease, and the disease types are scattered. The more common cases in grade Ⅲ were complete transposition of great arteries (accounting for 2.40% (52/2 166) of all cases with heart defects, 5.21% (52/998) of all cases with CHD) and pulmonary artery occlusion (type Ⅰ to Ⅲ) with ventricular septal defect (accounting for 2.17% (47/2 166) of all cases with heart defects, and 4.71% (47/998) of all cases with CHD). In grade Ⅳ, single ventricle (0.74% (16/2 166) of all cases with heart defects, 1.60% (16/998) of all cases with CHD) and left ventricular dysplasia syndrome (0.65% (14/2 166) of all cases with heart defects, 1.40% (14/998) of all cases with CHD) are more common. A total of 1 084 cases were successfully followed up, and 675 cases were born, 392 cases were terminated, spontaneous abortion occurred in 17 cases. The proportion of terminated pregnancy cases was significantly increased from grade Ⅰ to Ⅳ, accounting for 5.24% (21/401), 27.78% (70/252), 89.54% (214/239) and 95.56% (43/45), respectively. Among the terminated pregnancy cases, those with grade Ⅲ accounted for the highest proportion (54.59% (214/392)). The distribution of terminated pregnancy cases was mainly complex congenital malformations or diseases with very poor prognosis (pregnancy outcome grade Ⅲ and Ⅳ), and proportion of terminated pregnancy with pregnancy outcome grade Ⅰ and Ⅱ cases (normal variation or good prognosis) accounted for 5.36% (21/392) and 17.86% (70/392), respectively. The results of multivariate logistic regression analysis showed that pregnant women with low education (high school and below: OR=2.73, 95%CI 1.26-5.93, P<0.001; illiteracy: OR=3.27, 95%CI 1.29-7.10, P<0.001) and low family income (Annual income<100 000 yuan: OR=2.47, 95%CI 1.69-5.12, P<0.001) were more likely to choose termination of pregnancy in case of fetal heart defect. Conclusion: In Yunnan province and the surrounding high altitude areas, the disease distribution of fetal heart defect is mainly simple or low-risk disease, but the complex malformation, especially the disease with poor pregnancy outcome, accounts for a relative high proportion. Pregnancy termination also occurs in some cases with good pregnancy outcome. The education level and family income of pregnant women may affect their choice of pregnancy outcome in case of fetal heart defect.