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

Aim: 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. Material and methods: 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. Results: 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]). Conclusions: 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.