The role of ventricular disproportion, aortic, and ductal isthmus ultrasound measurements for the diagnosis of fetal aortic coarctation, in the third trimester of pregnancy

To analyze the role of ventricular disproportion, aortic, and ductal isthmus ultrasound measurements for the diagnosis of fetal aortic coarctation (AoCo) and to evaluate the prediction of a needed neonatal surgical intervention in the presence of a diagnosis of AoCo.We performed a prospective study on 41 fetuses (pregnancy age- 32 to 39 weeks, median 36 weeks) evaluated for left ventricle (LV) < right ventricle (RV) disproportion. Four fetuses were lost from evidence and five fetuses with complex cardiac malformations were excluded. The remaining group of 32 fetuses and newborns were evaluated.AoCo was confirmed in 9 neonates (28.12%), all requiring surgical treatment in the neonatal period. Significant statistical differences were found in Z-score (p=0.0023) and dimensions (p=0.0029) of the aortic isthmus between the neonates with normal aorta and those with AoCo. If the values of RV/LV>1.5, Ductus/Ao isthmus >1.4, and Ao isthmus <4.2 mm are concomitantly accomplished, 83.3% of the fetuses (20 of 23) did not necessitate neonatal surgical intervention. Five of the 9 operated newborns had all three parameters with values over the threshold. The probability for required surgery is 13.87 times higher when the Ao isthmus is <4.2 mm (OR = 13.87 [95% CI = 1.88 - 102.20]).The use of the combination between the three studied parameters with their cut-off score prediction decreases the false positive diagnosis of AoCo. The fetuses with ventricular disproportion developed only in the last trimester, had reduced chances for AoCo.