ADAM12s as a first-trimester screening marker of trisomy

Objective To evaluate the potential of maternal serum A Disintegrin And Metalloprotease 12‐S (ADAM12s) as an additional marker for the combined test in the Dutch first‐trimester national Down syndrome (DS) screening program. Methods Serum samples were collected between 2004 and 2007 as part of the national program. A total of 218 singleton cases of trisomy 21 (DS), 62 trisomy 18 (Edwards syndrome) and 29 trisomy 13 (Patau syndrome) were identified. All cases were matched with controls for gestation, maternal weight and maternal age. The serum concentration of ADAM12s was determined ‘blind’ to outcome and expressed in multiples of the gestation‐specific median for controls (MoM). Results The median ADAM12s was 1.00 MoM in controls and in the DS cases at 8, 9, 10, 11, 12, 13 weeks it was 0.45 (n = 3), 0.73 (22), 0.74 (53), 0.85 (37), 0.92 (71), 1.06 (32) MoM, respectively. The median for trisomy 18 was 0.85 MoM and for trisomy 13 0.63 MoM. Conclusion The ADAM12s MoM values were clearly reduced in early first‐trimester for all trisomies. However, the screening performance for DS did not greatly improve adding ADAM12s. ADAM12s could be an additional biochemical marker for first‐trimester screening for trisomies other than DS. Copyright © 2009 John Wiley & Sons, Ltd.