Endometrial and fetoplacental markers in pregnancies with fetal congenital nephrosis

Congenital nephrotic syndrome of the Finnish type [CNF] is an autosomal recessive disorder leading to death in early childhood, if treated conservatively without early renal transplantation. Prenatal screening at midtrimester is feasible by measuring maternal serum alpha-fetoprotein [MSAFP], elevated amniotic fluid [AF] AFP being the only diagnostic test in population screening. We studied whether concentrations of other pregnancy-related markers offer any ancillary procedure for screening.

In a prospective case-control study, the concentrations of maternal serum human chorionic gonadotropin [hCG], unconjugated estriol [uE3], human placental lactogen [hPL] and placental protein 14 [pp14] were measured in samples from six singleton pregnancies associated with fetal CNF and from 18 matched controls at 15 weeks of gestation.

In the CNF group, mean hCG and pp 14 concentrations were slightly elevated, whereas uE3 and hPL concentrations were within the lower normal range. None of these differences were statistically significant and the distribution of these values was too wide to use them for screening.

Low unconjugated E3 and elevated hCG concentrations were expected, since newborns with CNF are growth-retarded and have large placentas. The extent of these alterations was not sufficient to identify high risk pregnancies. Substantial differences in the maternal serum concentrations of hPL and pp 14 were not observed. Hence, MSAFP screening at midtrimester is the strategy of choice for prenatal detection of CNF.