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

OBJECTIVE

To evaluate the concentrations of human placental growth hormone (hPGH) in amniotic fluid (AF) at gestational mid-trimester in normal pregnancies and in pregnancies complicated by Down's syndrome.

DESIGN

AF samples from 21 women with Down's syndrome pregnancies were analyzed retrospectively. About 47 AF samples from women with singleton, uncomplicated pregnancies, who gave birth to healthy neonates with birth weight appropriate for gestational age were used as controls. All AF samples were obtained during amniocentesis for fetal karyotyping at 16-23 weeks' gestation. hPGH levels were measured by a solid phase immunoradiometric assay using two different epitopes.

RESULTS

The mean hPGH values in the AF of the Down's syndrome-affected pregnancies were significantly higher (P<0.05) compared to those of normal pregnancies, at 16-23 weeks' gestation: mean-value+/-SD in the AF was 1.96+/-1.35 microg/l vs. 0.82+/-0.67 microg/l.

CONCLUSIONS

Higher hPGH levels in AF were found in pregnancies affected by Down's syndrome as compared to normal pregnancies at gestational mid-trimester. hPGH was detected in all AF samples, and it provides evidence that this pregnancy-specific hormone enters the fetal compartment and is not limited to the maternal circulation. The physiological role and effect of hPGH on fetal growth in normal and pathological pregnancies needs further investigation.