The Value of Fetal MRI in the Prediction of Lethal Pulmonary Hypoplasia after Preterm Premature Rupture of Membranes

Purpose: To evaluate the predictive value of MRI volumetry in terms of lethal pulmonary hypoplasia after preterm premature rupture of membranes (pPROM). We hypothesized that with the information obtained by fetal MRI, it would be possible to predict lethal pulmonary hypoplasia. Patients and Methods: This study was a retrospective cohort study in a single large tertiary perinatal referral center including forty-nine fetuses after pPROM, between gestational weeks 16 and 27, who were investigated by MRI lung volumetry. Measured fetal lung volume was expressed as a percentage of the expected lung volume derived from our own standard curves. Fetal outcome was classified in lethal pulmonary hypoplasia and survival without pulmonary hypoplasia until discharge. Results: The percentage of expected lung volume differed significantly between 73% in lethal pulmonary hypoplasia and 102% in survivors without pulmonary hypoplasia (p<0,05). A measured lung volume lower than 60% of the expected lung volume correlated 100% with neonatal death. By logistic regression the occurrence of lethal pulmonary hypoplasia could be predicted with a sensitivity of 69% and a specificity of 91%. The positive predictive value of lung volume for lethal pulmonary hypoplasia was 79%. Conclusion: Fetal MR lung volumetry is a useful tool for predicting lethal pulmonary hypoplasia in patients with pPROM remote from term.