Follow-up of fetuses with congenital diaphragmatic hernia: The quantitative lung index.

Objective: To assess the longitudinal behavior of Quantitative Lung Index (QLI) for the follow-up of fetuses with congenital diaphragmatic hernia.

Study Design: Retrospective study of fetuses with isolated left congenital diaphragmatic hernia. The fetuses were assessed by ultrasound at different gestational ages and QLI was retrospectively calculated by means of previous lung-to-head ratio measurements. We used a random effects model (mixed model with repeated measurements) to compare the performance of the QLI in operated and non-operated fetuses throughout pregnancy.

Results: Fifty-eight cases of isolated left diaphragmatic hernia with complete follow-up were assessed in Hospital Universitari Vall d'Hebron in Barcelona (2003-2015). Thirty-eight of them were managed expectantly (non-TO) and the other 20 underwent tracheal occlusion (TO). All fetuses undergoing tracheal occlusion had lung-to-head ratio (LHR) <1, observed-to-expected LHR (o/eLHR) ≤45%, QLI <0.6 and liver up inside the thorax. The survival rate was 87% for the non-TO group and 60% for the TO group (p = 0.02). The QLI remained constant throughout pregnancy in both groups. The QLI in the TO group had lower values than the non-TO group (p < 0.03).

Conclusion: The quantitative lung index was constant during pregnancy. This index was lower in fetuses undergoing tracheal occlusion but no significant changes were seen in its performance during pregnancy.