Q. I am 34 years old. Please comment on my NT scan and double marker test result.

Answered by
Dr. Jimesh H Mavani
and medically reviewed by iCliniq medical review team.
This is a premium question & answer published on Nov 28, 2019

Hello doctor,

I am a 34-year-old female. Kindly expain my NT scan and double marker test result.

PAAP -A - 3.37 miU/ml.

HCG, free beta - 147.00 ng/ml.

NT value - 1.40mm.

Trisomy 21 - 1:227.

Dr. Jimesh H Mavani

General Practitioner Obstetrics And Gynaecology


Welcome to icliniq.com.

Let me explain to you first why this report is done and what it is about.

Basically it is a screening test and results of that do not indicate that baby has a problem. It just indicate that what are the chances of your baby to have some congenital anomalies like Down's syndrome, Patau syndrome, Turner syndrome, Edward syndrome. These all are congenital syndromes and the baby can have minor to major congenital birth defects if you continue the pregnancy. These chances are given in result in terms of 1:227 as in your case about Down's syndrome.

This means according to the available data with report value of your blood, sonography findings, age, and other factors there are chances of getting pregnancy positive with Down's syndrome is 1 out of 227 pregnancy like yours with matching factors. So it also means that out of 227 pregnancy like yours, 226 pregnancy are still normal and there is no problem in baby. When the report is below cut off value which is 1:250, report is given as high risk and otherwise low risk.

So in cases of high risk reports we have to do the confirmatory test to check whether the baby has Down's syndrome or not in your case. And for confirmation, we have to take baby cells directly and test for karyotyping. For obtaining baby cells we usually remove liquid around baby under sonography guidance and sent this liquid for the test. They will separate the baby cells from the liquid and do test on it. But for removing the liquid we have to puncture through the abdomen and it has its own risk. This procedure is called amniocentesis. And due to this risk, we have to segregate high risk and low risk and do test only at high risk for confirmation.

But for you, one positive thing is that in the value of percentage there is more than 99% chance that the baby does not have any problem with the report 1:227. I have also seen patients with 1:5 reports and which turns out normal after amniocentesis. So at the same time, it is positive as well as negative news for the couple. But we have to go forward with this.

I hope this helps.

Was this answer helpful?


Also Read Answers From:

Comprehensive Medical Second Opinion.Submit your Case

Related Questions & Answers

USG at 34 weeks says fetal cavum septi pellucidi width is increased. Should I be worried?

Query: Hello doctor, I am 34 weeks pregnant. Until two weeks ago, all the ultrasound reports were normal. The chance of Down's syndrome was 1 in 20000. But, two weeks ago they accidentally noticed a dent on my baby's head and cavum septi pellucidi (CSP) was slightly more than the 2SD. I was told to repea...  Read Full »

Do my wife's NT scan and double marker test results show a high risk for Down's syndrome?

Query: Hi doctor, My wife had NT scan and double marker test at 12 weeks and 3 days of pregnancy. The report is as follows, CRL is 59.2 mm, NT is 1.45 mm, free beta-hCG is 84.84 IU/L, equivalent to 2.217 MoM and PAPP-A 0.712 IU/L equivalent to 0.282 MoM. Trisomy 21 is 1: 450 1:47 and trisomy 18 is 1: 5315...  Read Full »



Ask your health query to a doctor online?

Ask a General Practitioner Now

* guaranteed answer within 4 hours.
Enter Your Health Query
You can upload files and images in the next step.



Disclaimer: All health Q&As published on this website is not intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek the advice from your physician or other qualified health-care providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website.