ESTIMATION OF GESTATIONAL AGE FROM STUDY OF AMNIOTIC-FLUID AND CLINICAL-ASSESSMENT

  • 1 January 1977
    • journal article
    • research article
    • Vol. 117  (8) , 886-890
Abstract
Study of 108 samples of amniotic fluid obtained between 28-42 wk gestation from 101 patients revealed that in normal pregnancies the creatinine concentration, lecithin/sphingomyelin (L/S) ratio and percentage of fat cells correlated better with the gestational age of the newborn, assessed by clinical criteria, than did the bilirubin and Na concentrations. A creatinine concentration of 1.75 mg/dl or more, an L/S ratio of 4 or more and a fat cell percentage of 10 or more correlated significantly with a gestational age of 37 wk or more. In abnormal pregnancies (those with obstetric or medical complications or both) the mean creatinine concentration in the amniotic fluid was significantly less than expected for gestational age in fetal dysmaturity and greater than expected when the mother had diabetes. The mean L/S ratio in the amniotic fluid was elevated when the mother had hypertension or smoked and in cases of fetal dysmaturity or long interval between rupture of the membranes and delivery; it was significantly lower than normal when the mother had diabetes. The mean bilirubin concentration in the amniotic fluid was significantly lower than normal when the mother had hypertension. When the mother had diabetes, maturity of the fetal lung, liver, skin and brain appeared to be delayed, according to the values for the amniotic fluid constituents.