Maternal serum human placental growth hormone at 11 to 13 weeks in trisomy 21 and trisomy 18 pregnancies

OBJECTIVE: To investigate the maternal serum concentration of human placental growth hormone (hPGH) in trisomy 21 and trisomy 18 pregnancies at 11 to 13 weeks of gestation and to examine the possible association between fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). METHODS: The maternal serum concentration of hPGH at 11 to 13 weeks was measured in a case-control study from 28 pregnancies with fetal trisomy 21, 28 with trisomy 18 and 112 pregnancies with euploid fetuses. The median hPGH multiple of the median (MoM) in trisomy 21 and trisomy 18 pregnancies were compared with euploid pregnancies. RESULTS: Serum hPGH was significantly lower in trisomy 21 (0.93 MoM) and trisomy 18 (0.62 MoM) compared to euploid pregnancies (1.02 MoM). There was a significant association between serum hPGH and PAPP-A in both the euploid (r = 0.258, p = 0.006) and trisomy 21 pregnancies (r = 0.410, p = 0.030) but not in trisomy 18 pregnancies (p = 0.445). CONCLUSION: In the first trimester, serum hPGH in trisomy 21 and trisomy 18 pregnancies is reduced. This is the opposite of findings in previous studies reporting that in the second trimester, trisomy 21 and 18 pregnancies have increased hPGH.