RESUMEN
Multiple ultrasonic parameters namely p1acental maturity grading, foetal biparietal diameter measurement [BPD] and the presence or absence of free floating particles [FFP] in amniotic fluid were individually determined as well as combination in 109 high risk pregnant women undergoing amniocentesis for maturity testing in their last weeks of pregnancy. An L/S ratio was determined in amniotic fluid in all patients, while analysis for phosphatedy leglycerol [PG] was carried out only in diabetic patients. A grade III placental maturation predicted 32 of 72 mature phospholipid parameters [44%]. APBD > /= 92 mm predicted 43 of 70 mature phospholipids parameters [61%]. The presence of FFP predicted 37 of 72 mature phospholipids parameters [51%]. Combined BPD > /= 92 mm and/or grade III placenta and/or presence of FFP in one ultrasonic screen predicted 68 of 72 mature phospholipid parameters [94%]. It is concluded that combined ultrasonic aranteters in one screen may obviate the need for amniocentesis to determine foetal lung maturity