Feasibility of fetal cardiac biometry measurement at 11-14 weeks scan - a cross-sectional study.

Abstract

Objective: To study the feasibility of fetal cardiac biometry measurement between 11 and 14 weeks in low-risk singleton pregnancies.

Methods: A cross-sectional study was conducted at a single tertiary care center between June 2022 and March 2024 in 129 singleton low-risk mothers in the South Indian population. All subjects included in the study underwent early fetal echocardiography at 11-14 weeks of gestation. The parameters interrogated were the heart length, heart width, heart circumference and area, chest circumference, ventricular chamber length and width, the transverse diameter of aortic and pulmonary annulus, and the transverse diameter of aortic isthmus.

Results: In our study, the success rate of measuring the fetal heart biometry was 33% at 11 weeks, 72% at 12 weeks, and 77% at 13 weeks, respectively. Measurements of outflow tracts and aortic isthmus were difficult. The exclusion of aortic isthmus diameter from the biometric parameters increased the success rate to 50% at 11; weeks, and 80% at 12 and 13 weeks, respectively. Maternal body mass index, any abdominal scar from previous surgeries, and position of placenta had no statistically significant correlation with feasibility of cardiac biometry.

Conclusions: Our study showed early fetal cardiac biometry is feasible. These measurements can be a helpful tool in the generation of nomograms for the population which can aid early identification of congenital cardiac defects, their follow-up and prognostication.