Branch pulmonary artery Doppler parameters predict early survival-non-survival in premature rupture of membranes

Background Preterm premature rupture of membrane (pPROM) leads to high neonatal mortality due in part to severe lung hypoplasia (LH). In other causes of severe LH, fetal echo-based parameters of smaller branch pulmonary arteries (PA), shorter acceleration to ejection time ratio (AT/ET), increased peak early diastolic reverse flow (PEDRF), and higher pulsatility index (PI) are predictive of worse neonatal outcome. We sought to determine whether these parameters correlated with worse clinical outcome in pPROM. Methods Twenty-five pregnancies complicated by pPROM were prospectively recruited. Fetal echocardiography was used to evaluate branch PA diameters and Doppler parameters. Clinical records were reviewed. Fetal echo findings were compared between early survivors and non-survivors. Results Of 25 pPROM cases, 5 had early neonatal demise (<= 3 days) due to respiratory insufficiency. While gestational age at pPROM, fetal echo, and at birth did not differ, amniotic fluid index (AFI) was significantly lower in early non-survivors compared to survivors (p = 0.05). No difference was observed in PA diameter, PEDRF, or PI; however, branch PA AT/ET was significantly shorter in non-survivors (right PA median 0.12 (0.11-0.16) vs. survivors 0.17 (0.14-0.21),p = 0.046 and left PA 0.12 (0.09-0.13) vs. survivors 0.16 (0.11-0.21),p = 0.042). Conclusions We found a significantly lower AFI and shorter fetal bilateral branch PA AT/ET to be associated with early neonatal demise following pPROM.