Letter: Amniotic fluid on maternal urine?

Vaginal fluid prolactin: a reliable marker for the diagnosis of prematurely ruptured membranes. Comparison with vaginal fluid alpha-fetoprotein and placental lactogen

The aim of this study is the evaluation of the reliability of vaginal fluid (VF) prolactin (PRL) for detecting prematurely ruptured membranes (PROM) and the comparison of this marker with vaginal fluid alpha-fetoprotein (AFP) and placental lactogen (HPL). In 21 pregnant women with recent or prolonged PROM from 20 to 41 weeks' gestation, in whom intact membranes were never found subsequently VF- and MS-PRL, -AFP and -HPL were measured by enzyme immunoassays, which are sensitive and very rapid. The same markers were also measured in MS, VF and urine samples (U) in 12 pregnant women of the same gestational age, without PROM, in whom the membranes were ruptured later during labor. In PROM, independently of prematurity and duration of PROM VF-PRL levels were significantly higher (2-10-fold) than the paired MS-PRL (p less than 0.0001) and ranged from 130 to 2315 ng/ml. In contrast, VF-PRL and urine PRL concentrations in pregnancies without PROM were very low or undetectable (range: 0-5 ng/ml and 0.15-1 ng/ml, respectively). Vaginal fluid AFP values in PROM from 20th to the 33rd week of pregnancy were significantly higher (5-50-fold) than the paired MS-AFP (p less than 0.01) and ranged from 103 to 5500 ng/ml. In PROM after the 33rd week of pregnancy, VF-AFP values were either lower (1/3), or equal to, or even higher (up to 2-fold) than MS-PRL. On the contrary in pregnancies with intact membranes, VF-AFP were always less than 9 ng/ml and urine AFP was undetectable (range: 0.2-1.1 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Prenatal diagnosis of Tay-Sachs disease: studies on the reliability of hexosaminidase levels in amniotic fluid

Measurement of hexosaminidase A activity in amniotic fluid was found to be a reliable diagnostic test in the prenatal diagnosis of Tay-Sachs disease. Including normal control specimens, analysis of 39 amniotic fluid samples have correctly predicted the condition of the fetus or, in pregnancies not yet come to term, have been in agreement with results from cultured cell extracts. In each case where both fluid and cultured cell extracts were analyzed, the results were in agreement. Analysis were performed by means of Cellogel, starch gel electrophoresis, polyacrylamide gel electrophoresis, or heat inactivation.

Analysis for amniotic fluid crystallization in second-trimester amniocentesis

A potential complication of second-trimester amniocentesis for genetic indications is inadvertent needle insertion into the maternal bladder, resulting in aspiration of urine rather than amniotic fluid. Amniotic fluid forms a characteristic crystalline arborization pattern when allowed to air dry. We utilized this property of amniotic fluid to distinguish amniotic fluid from maternal urine. In 24 of 25 cases studied in a randomized blind fashion the crystalline arborization test correctly identified amniotic fluid, whereas none of the 25 urine samples showed this pattern. Our study indicates that the crystalline arborization test is reliable in distinguishing amniotic fluid from maternal urine during the second trimester of pregnancy.