Adding ADAM12 in risk calculation program does not improve the detection rate of trisomies 18 and 13 in first trimester screening.

OBJECTIVE: To investigate first trimester levels of ADAM12 in trisomy 18 and 13 pregnancies and whether incorporating ADAM12 in the LifeCycle™ risk calculation program of trisomy 18 and trisomy 13 screenings can improve the detection rates of trisomies 18 and 13. METHODS: ADAM12 was incorporated in the LifeCycle™ risk calculation program. A specific algorithm with cut-off of 1:200 for screening of trisomies 18 and 13 was employed. Detection rates for trisomies 18 and 13 were calculated. RESULTS: There was a significant difference in ADAM12 levels between trisomy 18 pregnancies and controls during the gestation weeks 9 + 0 - 10 + 6, but not thereafter. In trisomy 13 pregnancies there was no difference in weeks 9 + 0 - 10 + 6, but there was in 11 + 0 - 12 + 6. The specific algorithms for trisomies 18 and 13 combined with algorithm for trisomy 21 yielded detection rates of 73.7% and 66.7%, respectively. The combined false positive rate was 4.6%. Adding ADAM12, the detection rate for trisomy 18 was the same, at 73.7% and for trisomy 13, at 66.7%. CONCLUSION: ADAM12 did not improve the detection rate.

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.

Effect of a new marker, ADAM12, on Down risk figures in first trimester screening.

OBJECTIVE: To investigate whether incorporating the measurement of ADAM12 in the risk calculation program LifeCycle, can improve Down screening in the first trimester. METHODS: In a retrospective case control study, maternal serum ADAM12 concentrations were measured and compared in Down syndrome cases (n = 53) and in controls (n = 226) obtained from first trimester (9-12 weeks) screening samples in Oulu and Kuopio University Hospitals. Median concentration ( microg/l), observed and regressed (weight corrected) MoMs of ADAM12 were calculated. RESULTS: There was a significant difference in ADAM12 levels between Downs and controls during the pregnancy weeks 9 + 0 to 10 + 6, but not thereafter. By adding ADAM12 to the marker set used in the risk calculation program, one screening false negative Down syndrome case occurred in the affected population, which did not alter false positive rate. CONCLUSION: Adding ADAM12 as a parameter in Down screening did not cause radical changes in the risk value. The test might be useful at 9 and 10 weeks in which it might have the potential to improve the performance of the risk assessment especially for women receiving a result close to the high-risk cut-off. The real influence of ADAM12 remains to be elucidated in larger studies incorporating ADAM12 to the risk calculation program.

Clinical first-trimester routine screening for Down syndrome in singleton pregnancies in northern Finland.

OBJECTIVE: The purpose of this study was to compare the efficacy of both separate and combined maternal serum testing and fetal nuchal translucency measurement in the first trimester screening for Down syndrome in northern Finland. STUDY DESIGN: The following screening tests were evaluated: measurement of nuchal translucency (NT) alone; serum screening (pregnancy-associated plasma protein A [PAPP-A] and free beta subunit of human chorionic gonadotropin [beta-hCG]) alone; and combined screening (NT plus PAPP-A and free beta-hCG). RESULTS: The participants comprised 7534 pregnant women during the 10+0-12+6 weeks of pregnancy. All 7534 women participated in serum screening, and 4765 women participated in combined screening. In the serum screening-alone group, there were 30 cases of trisomy 21, of which 23 (76%) were detected. In the combined-screening group, there were 24 cases of trisomy 21 and 21 (87.5%) were detected. In the combined-screening group NT alone detected 15 cases of Down syndrome (62%). CONCLUSION: Combined screening is the method of choice for Down syndrome screening.