OC173: Fetal distal pulmonary artery blood flow as a predictor of pulmonary hypoplasia in congenital diaphragmatic hernia

Abstract

Objective: To determine if the fetal peripheral pulmonary artery Doppler evaluation can predict the presence of lethal pulmonary hypoplasia in cases of congenital diaphragmatic hernia. Methods: Distal pulmonary artery Pulsatility Index (PI) was calculated in 13 pregnancies with congenital diaphragmatic hernia between 32 and 36 gestational weeks. Associated malformations were discarded by a normal second trimester ultrasound and a normal echocardiography in all cases except one presenting a coarctation of the aorta, this one was eliminated for the posterior data analysis. Associated chromosomal defects were also discarded by fetal kariotype in all cases. Other variables as the presence of polyhydramnios, the side of the hernia, the presence of stomach or liver herniation, the gestational weeks at diagnosis, the weight at birth and the newborn evolution were also recorded. All these variables were compared between the cases that died postnatally and the one’s that survive. Results: All deaths were attributable to pulmonary hypoplasia. The distal pulmonary artery PI was higher in the group that died than in the survivors (P < 0.01); with a mean of PI value of 2.64 (95% CI 2.51–2.76) in those dying and a mean of 2.05 (95% CI 1.71–2.39) in the survivors. All the other analysed values did not present differences between the two groups. Conclusions: Distal pulmonary artery Doppler PI may be useful in the prediction of lethal pulmonary hypoplasia in fetuses affected with congenital diaphragmatic hernia. These results agree with other author’s works which suggest lower pulmonary artery PI values in fetuses without risk of developing pulmonary hypoplasia, showing a low resistance vascular pulmonary bed.