Congenital nephrotic syndrome: prenatal diagnosis and genetic counselling by estimation of aminotic-fluid and maternal serum alpha-fetoprotein

Amniotic fluid alpha-fetoprotein levels and the prenatal diagnosis of neural tube defects: a collaborative study of 2180 pregnancies in the Netherlands

Amniotic fluid alpha-fetoprotein (AFP) concentrations were measured in 2180 patients at risk of fetal abnormality because of previous history, family history, advanced maternal age, suspected fetal growth retardation and hydramnios. In 12 patients investigated before 20 weeks gestation, pregnancy was terminated because of a raised amniotic fluid AFP-level: 11 fetuses had neural tube defects (NTDs) and one had a congenital nephrosis. There were no false negative results in the 1927 patients tested before 20 weeks and with a pregnancy of known outcome. In patients tested after 20 weeks, the amniotic fluid AFP concentration was raised in 20 cases of anencephaly, in 9 fetuses with severe congenital malformations without NTD and in one apparently normal fetus. Of 428 patients with a previous offspring who had a NTD, only 8(1.9 per cent) again had a fetus with a NTD.

Prenatal diagnosis of Meckel syndrome: alpha-feto protein and beta-trace protein in amniotic fluid

Meckel syndrome was diagnosed prenatally by alpha-feto protein and beta-trace protein determinations in amniotic fluid. No central nervous system anomalies were detected in the affected fetus, who presented with large polycystic kidneys and polydactyly. An excessive synthesis of these fetal proteins by the dysplastic kidneys is suggested, allowing for the possibility of prenatal diagnosis of polycystic kidneys in families at risk for this disease. The present family emphasized the importance of amniocentesis in pregnancies at risk for Meckel syndrome, regardless of the presence of a defect in neural tube closure.

Fetal proteinuria in diagnosis of congenital nephrosis detected by raised alpha-fetoprotein in maternal serum

High concentrations of alpha-fetoprotein (alpha-FP) were found at 14, 19, and 21 weeks gestation in the serum of a woman with a history of unexplained fetal death in her previous pregnancies. The alpha-FP concentration of the liquor also was high at 21 weeks and the pregnancy was terminated. Though the fetus was macroscopically normal, measurement of albumin, alpha-FP, IgG, and alpha2-macroglobulin in the fetal urine showed a selective proteinuria, and congenital nephrosis was diagnosed after examination of the fetal kidneys by electron microscopy. Possibly some fetuses reported to be "false-positive for neural tube defect" may have had renal lesions of this nature. Examination of fetal urine may be the simplest initial diagnostic procedure in any future case.

Toxemia of pregnancy: assessment of fetal distress by urinary estriol and circulating human placental lactogen and alpha-fetoprotein levels

The efficacy of three biochemical methods for the detection of fetal distress was assessed in a prospective study of 224 singleton pregnancies complicated by toxemia. Fetal distress was diagnosed in 65 cases (29 per cent). Abnormally low urinary estriol (E3) excretion pointed out 63 per cent, low serum levels of human placental lactogen (HPL) 27 per cent, and elevated maternal serum alpha fetoprotein (AFP) 10 per cent of distressed fetuses. The efficacy of each test increased with the severity of maternal disease. The frequencies of false pathologic levels were: E3 19 per cent, HPL 0 per cent, and AFP 1 per cent of the cases with a normal fetal outcome. Although E3 was by far the most effective marker, abnormal levels of HPL and AFP provided supportive evidence for fetal distress by pointing out those cases in which E3 reading was not a false positive.