Maternal serum ADAM12 (A disintegrin and metalloprotease) in chromosomally abnormal pregnancy at 11-13 weeks.

OBJECTIVE: The objective of this study was to investigate the potential value of ADAM12 (A disintegrin and metalloprotease) in first-trimester screening for trisomy 21 and other major chromosomal abnormalities. STUDY DESIGN: The concentration of ADAM12 was measured at 11-13 weeks in cases of trisomy 21 (n = 49), trisomy 18 (n = 28), trisomy 13 (n = 20), Turner syndrome (n = 29), triploidy (n = 10), and euploid pregnancies (n = 272). The levels of ADAM12, expressed as multiples of median (MoM), were compared in cases and controls and were assessed for association with free beta-human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein A (PAPP-A). RESULTS: The median ADAM12 value in trisomy 21 (0.961 MoM) was not significantly different from the euploid fetuses (1.013 MoM), but in trisomy 18 (0.697 MoM), trisomy 13 (0.577 MoM), triploidy (0.426 MoM), and Turner syndrome (0.747 MoM), the levels were significantly lower. In both the euploid and aneuploid pregnancies, there was a significant association between ADAM12 and free beta-hCG and PAPP-A. CONCLUSION: Maternal serum ADAM12 concentration at 11-13 weeks of gestation is unlikely to be useful in first-trimester screening for chromosomal abnormalities because in trisomy 21 the levels are not significantly different from normal, and in the other chromosomal defects, there is a significant association between ADAM12 and the traditional biochemical markers of free beta-hCG and PAPP-A.