A new non invasive method for the prediction of fetal lung maturity

We have observed by ultrasound (US) technology recurrent patterns in respiratory behaviour during the study of fetal breathing movements (FBMs) related with pulmonary maturity/immaturity. We aimed to correlate these findings with fetal lung maturity (FLM) tests currently performed in our institution in order to validate the hypothesis thai some FBMs patterns may correspond to FLM, independent from gender, weight and gestational age. We enrolled 39 high risk pregnancies in whom a complete US study of FBMs was performed and correlated to FLM tests. All women delivered by cesarean section within one week from amniotic fluid sampling. US-FLM was defined as presence of nasal fluid flow velocity waveforms (NFFVW) detected by Doppler flow plus spectral image analysis synchronous to tlıoracic movements (TM) as evaluated by M-mode. An US guided amniocentesis was performed and FLM testin» evaluated by L/S ratio, phosphatidylglycerol presence and lamellar bodies count. Diagnostic accuracy tor US-FLM, with RDS as endpoint parnmeter, was as follows: sensitivity: 100%, specificity: 80%, FPV: 73% and NPV:100%.
FBMs a re known to reflect pulmonaıy development and maturation and thııs are feasibly correlated with the risk of RDS. The synchronous presence of NFFVW and TM correlate accurately with conventional FLM tests.
We suggest that this non-invasive assessment of FLM may be the choice when ceıtain siuıaıion ari.se, sueh as: amniocentesis refusal, religious concerns, critical anhydramnios, laboratoıy logistic difficulties or heavy stained amniotic fluid sample.