Fetal congenital heart disease and fetal position – are they related?

Ultrasound (US) is the principal imaging modality used to diagnose and evaluate congenital heart disease (CHD), which is the most common birth defect worldwide, affecting 9.410 per 1000 newborns. Mother’s BMI, amniotic fluid index, and fetal mobility and position are factors that influence the precision and difficulty of prenatal US examination. In our study we considered whether fetuses with CHD have a predilection to any position. It has never been reported before. We analysed results of 1620 (control – 835, isolated CHD – 321, non-isolated CHD – 464) fetal cardiac US performed between June 2016 and September 2019 at the Department of Prenatal Cardiology. The following parameters: gestational age, fetal position, CHD, and non-cardiac anomalies/defects were taken into consideration for further statistical analysis. We observed a statistically higher frequency of right cephalic position (CII) among fetuses with CHD, as well as isolated and non-isolated CHD in comparison to healthy controls (p < 0.0001, p < 0.0001, and p = 0.0015, respectively; n = 1620). These findings may be an effect of more advanced gestational age of CHD patients. Hence, we performed further analysis in the age group ≥ 33 weeks of gestation, which also revealed statistically significant differences in the CII position in the group of CHD fetuses, especially isolated ones when compared to healthy controls (p = 0.0292 and p = 0.0049, respectively; n = 674). Fetuses with CHD had a predilection to right cephalic position more often than healthy fetuses. Because this factor determines the high-quality of US examination, it should be mentioned in medical reports of prenatal ultrasound.