Human Placental Growth Hormone Is Increased in Maternal Serum in Pregnancies Affected by Down Syndrome

Abstract

Objective: To evaluate the relationship between maternal serum levels of human placental growth hormone (hPGH) and fetal Down syndrome at gestational midtrimester. Methods: We retrospectively analyzed samples of serum from 21 women with Down syndrome pregnancies detected at gestational midtrimester. The samples were obtained at 16–23 weeks’ gestation during amniocentesis for fetal karyotyping. Sixty-two serum samples were used as controls, which were obtained at 16–23 weeks’ gestation from women with singleton, uncomplicated pregnancies, who gave birth to healthy neonates with a birth weight appropriate for gestational age. The hPGH levels were measured by a solid-phase immunoradiometric assay using 2 different epitopes. Results: The median hPGH values in the serum of the Down-syndrome-affected pregnancies were significantly higher (p < 0.05) than those of the normal pregnancies at 16–23 weeks’ gestation: the median value in the serum was 9.4 ng/ml (5th to 95th percentiles = 1.49–39.03) versus 4.7 ng/ml (0.53–7.88). Conclusion: The hPGH levels in maternal serum were found to be higher at 16–23 weeks’ gestation in pregnancies affected by fetal Down syndrome. Further investigation is needed to examine if maternal serum hPGH could be used as an additional marker in prenatal screening of Down syndrome at gestational midtrimester.

Increased levels of human placental growth hormone in the amniotic fluid of pregnancies affected by Down syndrome

“…This observation is consistent with previous reports [17,18] as well as a recent study by our group [19] showing increased maternal serum levels of hPGH in pregnancies affected by DS at gestational mid-trimester. The detection of increased hPGH levels in the AF of an aneuploidic pregnancy does not have any obvious clinical application, as the fetal karyotyping is performed following amniocentesis by using the amniotic cells.…”

“…High serum levels of hPGH have been detected in pregnancies affected by fetal DS [17,18]. In a recent study we confirmed increased maternal serum levels of hPGH in the second gestational trimester of pregnancies affected by this aneuploidy [19]. By using almost the same cohort we retrospectively analyzed AF samples obtained at the gestational mid-trimester with the aim to evaluate the concentrations of hPGH both in normal pregnancies and pregnancies affected by DS.…”

“…By using the hPGH maternal serum values measured in the same cohort of enrolled women (published previously [19]), we performed a correlation analysis for the hPGH levels in the paired samples of maternal serumamniotic fluid. In the 21 paired samples taken from women with DS affected pregnancies at 16-23 weeks' gestation, a statistically significant correlation between the hPGH values was found, by means of Pearson's correlation coefficients (r = 0.760, P < 0.001, positive correlation).…”

“…The presence of GH receptors in the placenta suggests a direct influence of hPGH on placental function through an autocrine or paracrine mechanism [11], and indicates a proliferative and secretory stimulator action in placental tissue [9]. It could be suggested that the high maternal serum and AF concentration of hPGH in pregnancies affected by DS is due to an attempt by the placenta to counteract the incipient fetal growth restriction by an enhanced secretion of the hormone [19]. This compensatory mechanism probably stimulates IGF-I synthesis in placental tissue and maternal hepatocytes.…”

Human placental growth hormone in normal and abnormal fetal growth

“…Various studies have reported a significant decrease in maternal serum PGH concentrations in pregnancies complicated by fetal growth restriction (FGR) (12,30), while increased maternal serum levels have been correlated with the presence of fetal chromosomal abnormalities (31–33). …”