Results suggest a substantial benefit of adding PlGF to the combined test.

What's already known about this topic? Four previously reported cases of trisomy 16 have shown reduced levels of pregnancy‐associated plasma protein‐A during first trimester screening for trisomy 21. Isolated increases in free β human chorionic gonadotrophin and nuchal translucency were observed in these four cases. What does this study add? During first trimester screening for aneuploidy, we observed a further 28 cases of trisomy 16, all of which had reduced levels of pregnancy‐associated plasma protein‐A consistent with previous reported cases. Increased free β human chorionic gonadotrophin and increased nuchal translucency were not a consistent finding in our 28 cases.

ADAM12 is a second trimester marker of Down's syndrome, with discriminatory power similar to existing markers. It could be considered in multi-marker combinations.

Background The current Down’s screening programme has the potential to identify pregnancies at risk of other significant chromosomal problems. However unless at increased risk for trisomy 21 these pregnancies are usually reported as low risk. This leaves women and their healthcare professionals unaware of potential problems and denies them opportunities for earlier intervention if desired. Methods All data from our regional CT screening programme where both the PAPP-A and hCG result fell below the 0.3 MoM were identified and pregnancy outcome reviewed. Results A total of 112 cases were identified comprising approx 0.16% of women screened. Abstract PA.10 Table   N Outcome 112 Abnormal Misc/ToP Normal Unknown Increased NT >3.5 mm or increased T21 risk on CT 27 23 (85%) 0 3 1 No risk given or not at increased risk 85 26 (31%) 4 51(60%) * 4 * Includes 2 babies born <30 weeks because of IUGR. The karyotype abnormalities were 30-trisomy18, 13-triploidy and 6 others. There were no cases of trisomy 21. Discussion Clinical teams and screening midwives need to be aware of the implications of a low/low result on screening. Ultrasound does not help to identify pregnancies where diagnostic testing may be of value. This group of women should not be labelled as low risk and should have the opportunity for an informed discussion about the implications of their results with a fetal medicine centre and consideration given to diagnostic testing. If the pregnancy continues they should be managed as high risk with obstetric input to monitoring of fetal growth and BP.