Fetal cardiac ultrasonography: An optimum gestational age of assessment

Abstract

OBJECTIVES: To identify the ability of acquiring fetal cardiacimages at different gestational age windows using ultrasound scan. DESIGN, SETTING AND METHOD: This was a prospective descriptive study using ultrasound machine “Alpinion EC-15 V4.0” and “Toshiba Aplio 300”. Fetal cardiac views at gestational age from 11 to 30 weeks were obtained by an expert in obstetric fetal echo. Low risk women with singleton pregnancy were recruited. The sample was stratified into 5 gestational age windows between 11 and 28 weeks. Ability to view four chambers, right and left out flow tracts, three vessels, aortic arch, ductal arch and superior and inferior vena cavae at each gestational window was assessed. RESULTS: A total of 313 pregnant women were analyzed. All seven fetal cardiac images were obtained at the gestational age of 18 weeks to 25+6. There was a sub-optimal acquisition of the three vessels and SVC/IVC (96.3%) at 26-30 weeks. Six out of seven cardiac images were possible in more than 80% of cases from 14 to 17+6 weeks. At the gestational age between 11 weeks to 13+6, the ability to view four chambers was 92.98% and the ability to view the rest of the images was as follows: right out flow tract – 38.6%, left outflow tract – 42.11%, three vessels - 38.6%, aortic arch- 36.84%, ductal arch- 35.09%, superior and inferior vena cavae-5.26%. CONCLUSION: Ability of acquiring fetal cardiac views was best at 18 to 25+6. Cardiac image acquisition is sub optimum in early gestations and beyond 26 weeks.