Maternal serum ADAM12 levels correlate with PAPP-A levels during the first trimester.

Background: We wished to investigate the correlation between a new Down screening marker ADAM12 (a disintegrin and metalloproteinase-12) and pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotropin (fbeta-hCG) during the first trimester of pregnancy.
Methods: ADAM12, PAPP-A and fbeta-hCG were measured in 225 serum samples of randomly chosen pregnancies with completely normal outcome. The samples were taken between pregnancy weeks 9+0 and 12+6.
Results: The ADAM12 levels tended to increase with advanced gestational age and the highest levels were detected at pregnancy week 12. The ADAM12 levels correlated with PAPP-A levels. After weight correction and logarithmic transformation the multiples of median (MoM) of ADAM12 still correlated with the MoMs of PAPP-A and also with the MoMs of fbeta-hCG. Smokers had lower ADAM12 levels than non-smokers.
Conclusion: The secretion of ADAM12 seems to resemble the secretion of PAPP-A in the end of the first trimester. Accordingly ADAM12 appears not to be a separate marker independent of PAPP-A. It remains to be assessed whether adding ADAM12 in Down screening risk calculation will reduce the false positive rate during the first trimester of pregnancy.
(Copyright (c) 2010 S. Karger AG, Basel.)