Screening tes of foetus for chromosomal abnormality-What tets when ?

Limitations of Scan at 13 weeks & 18 weeks(Anomaly-TIFA) ?? Take home message:-Scan cannot always exclude a chromosomal anomaly especially Down syndrome though may raise strong suspicion in NT scan but its detection chance at TIFA is negligible (Suspicion of Down). Quadruple marker is  +ve at 18 weeks : Now fior instance there is a  post cs case: with Q serum marker at 17 weeks is +ve. Then what nest? Straigt termination or aminoàconform by FISH then MTP at say 19 weeks. She had 2 CS earlier?? But USG level 2scan normal... should v terminate or investigate further... how?? Ans: We have to keep in mind that Q Top of Form

Ans: Q Amarker is a screening test .. One have to confirm by amniocentesis and then arrive at a firm & definitive  decision which is unquestionable.

 We should never terminate based on a blood test report and that too Triple / Q serum amylates test which are screening tets only-speaks in terms of probability-MoM! To do MTP based on Q tets more so when Scan report is normal à Its a crime against the fetus.

 Advise amino even if the scan is "normal" as a scan cannot exclude a chromosomal anomaly especially Down Syndrome. If proven abnormal then only offer termination. What is the cost of NIPT(done at 10-12 weeks )  18 k to 30k depending on the lab.

 If one dose MTP based on D marker tets and or Q marker tets without confirmation by CVS or say amnio then it may be compared to quackery à like it’s like saying "if urine sugar is positive, start Insulin" In my another case she was  already 19wks 6days......Irony is I  cannot do MTP even if amniocentesis is positiveàDelay by relatives to do amino or not and then  reports come late .In case of Q marker if +ve  1 out of 120 with such results will have DS which means 119/120 with such results will be normal. Which is 1% DS 99% normal. Sounds better now isn’t it? The chances of normal is still much higher than abnormal

Moreover the FISH for T21 result is available in 5 working days in most labs, even earlier.

 I too suggest Amniocentesis and Genetic counseling. I Dr Pal  dealt with  same type of pt 17 weeks now got it done Amino was done à which luckily was is normal -> so is now  continuing with pregnancy _To conclude à counseling to pt done and consent taken that both pros and cons for amniocentesis was explained. This(Q marker, NT, D marker , NIPT too ) are  just a screening test. Never to terminate on this. Counsel her and advise her on further testing... amniocentesis. If any one of them is +ve one and only answer is amniocentesis..but only after proper nonjudgmental  counseling