Prenatal prediction of pulmonary hypoplasia using the maternal hyperoxygenation test and neonatal outcome

HYPEROXYGENATION TEST AND NEONATAL OUTCOME RIMA BADER, JAMES HUHTA, University of South Florida, Pediatrics and Obstetrics, St. Petersburg, Florida OBJECTIVE: To evaluate maternal hyperoxygenation test (MHT) in predicting the outcome of fetuses at risk for neonatal pulmonary hypoplasia. STUDY DESIGN: MHT test was performed on 9 pregnant women (median maternal age 28.5 years) with fetuses with congenital anomalies(median gestation 31.5 weeks) that may cause pulmonary hypoplasia.(hypoplastic left heart syndrome(n = 2), congenital diaphragmatic hernia (left) (n = 2), Epstein anomaly with pulmonary artesia (n = 1), tetralogy of Fallot with absent pulmonary valve (n = 1), prune belly syndrome (n = 1), lung hypoplasia of unknown etiology (n = 2).During MHT the Doppler blood velocity pattern and PI in the first branch of either pulmonary arteries were obtained before and 1015 minutes after maternal breathing of 100% oxygen was obtained for each fetus at R30weeks GA. An increase in fetal blood flow with oxygen (a decrease of R20% in PI) was considered positive for pulmonary reactivity. The primary outcome for this study was neonatal death from possible pulmonary hypoplasia. RESULTS: Of the 9 fetuses tested, 5 (55%) had a reactive MHT and all were delivered and alive and well (100%). Of the 4 fetuses (45%) who had a non reactive MHT 2 died in the early neonatal period (50%) and 1 (25%) was born alive but no data was available for followup, 1 (25%) is alive and well. CONCLUSION: Preliminary data suggest that testing fetal pulmonary vascular reactivity with MHT could be useful in assessing fetal pulmonary vascular resistance prenatally and in predicting the neonatal outcome. More data is needed to assess the limitations of this test.