Background Ventricular and arterial disproportion with right sided dominance in the fetus are associated with coarctation of aorta. We present the postnatal outcomes of fetuses diagnosed with arterial and/or ventricular disproportion with emphasis on management strategy.

Methods Retrospective review of fetal echocardiography reports and postnatal outcome of fetuses with arterial and/or ventricular disproportion evaluated between January 2012 and December 2014 at Birmingham Women’s Hospital. Parameters assessed were arterial disproportion, ventricular disproportion, posterior shelf and abnormal flow across the isthmus. The fetuses were categorised into the following three groups - Group A (High risk) – Delivery at unit with a tertiary neonatal centre and postnatal prostaglandin prior to echocardiogram; Group B (moderate risk) – No prostaglandin but echocardiogram prior to discharge, and Group C (low risk) – postnatal clinical assessment.

Results Of the 68 fetuses with disproportion, there were 3 terminations of pregnancy, 1 intrauterine death and 2 lost to follow up. Of the remaining 62 fetuses, 38 were in Group A, 11 in Group B and 13 in group C. In Group A, 21/38(55%) had coarctation of aorta confirmed postnatally. In Group B, 1 neonate had coarctation which was identified and operated on prior to discharge. No cases of coarctation were identified in group C. Comparing the fetuses with postnatal coarctation in Group A to those that did not, fetuses with coarctation had more antenatal scans (median 3 vs. 2; p < 0.05) and the decision to start prostaglandin was made earlier in pregnancy (median 29 weeks gestation versus 33 weeks; p < 0.05).

Conclusions Risk stratification was a safe and effective way of managing fetuses with antenatal disproportion. However, 45% (n = 17) of neonates started on prostaglandin did not have coarctation. Further study is required to improve the predictive accuracy of antenatal diagnosis in this difficult subset of patients.