<s>[INST] I went for NT scan and double marker test at the gestational age of 12 weeks 2 days. My NT through ultrasound is 1.5 mm. Double marker blood test has foll values - PAPP A - 1.23 (Corr MoM) HCGb - 0.43 (Corr MoM), 18.7 ng/ml Risks for TRisomy 21 and 18 are stated as Low in the report. Are my values good? I am a little concerned with a bit low bHCG value. [/INST] Hi, thanks for the query.Your NT measurement is within normal range for the gestational period (upper limit is 3 mm). Your double markers are also fine. Low beta hcg is not of concern in your case as the nuchal translucency is normal and PAPP-A is also normal. Low beta hcg is worrisome in case nuchal translucency is elevated and PAPP -A is decreased. This triad of findings is associated with chromosomal abnormalities. ( trisomy 18 and trisomy 13) and doesn't match with your report which is normal.  Hope this information is useful. Good luck. </s>