Applicability of standardized early fetal heart examination in the obese population

Abstract

Objective—This study aimed to evaluate the impact of obesity on early evaluation of fetal cardiac landmarks using a standardized examination method at the time of nuchal translucency scan. Methods—This was a cross-sectional study of an ongoing prospective cohort at high risk for congenital heart defects. We used a standardized examination protocol using 2-dimensional sonography with power Doppler in the evaluation of fetal cardiac landmarks consisting of 4-chamber view, outflow tract relationship, and transverse arches view. The study population was stratified based on maternal body mass index into nonobese (<30 kg/m2) and obese (≥30 kg/m2). Groups were compared in terms of satisfactory evaluation of fetal cardiac landmarks, transvaginal sonography use, and scan times required for the evaluations. Subanalysis was performed by further categorizing obesity into nonmorbid obesity (30.0–39.9 kg/m2) and morbid obesity (≥40 kg/m2). Results—A total of 190 patients were evaluated. Of these, 48.4% (n = 92) were obese. The most common indication for fetal cardiac assessment was maternal pregestational diabetes mellitus (42.6%). Transvaginal sonography was utilized in one nonobese woman (1.4%) and 11 obese women (12%) (P = .002). The satisfactory evaluation of 4-chamber view, outflow tract relationship, transverse arches view, and all views were not significantly different between groups (P > .05). The scan time was about 5 minutes longer in the obese group compared with nonobese group (P = .020). Conclusions—Obesity does not hamper early evaluation of fetal cardiac landmarks around the time of nuchal translucency scan. However, obese patients are more likely to require transvaginal examinations.