hi,
i' m new to this board.i' m 12 weeks pregnant now.i had my NT screen test today.doctor did my u/s & said that nuchal translucency is 3mm which is abnormal.she said it should be less than 2mm.now i' m really worried if baby has down' s syndrome or any other chromosomal abnormality.i' m cant stop crying.i' m so scared.my doctor has referred me to an other specialist to perform a high tech u/s to get a 2nd opinion.can you please tell me what should i expect?has anyone gone through this?what was your results with NT scan?please need your help.i' m not able to think anything at this point of time........... Anu replied. Hi shruthi,

how is ur baby..? is he fine and healthy?
Now i' m in ur situation.My Nt scan result shows 3mm thickness at 13 weeks.Im so worrieand crying all time...I can' t do anything...please help me... preeti replied. Hi Shruti,

An abnormal test doesn' t mean that your baby will have down syndrome. 3mm thickness is not abnormal, it means that the baby is at high risk. Did you go through a blood test? Screening with your blood test gives more accuracy. What was the result you got? for example you may be told that your baby' s chances of having Down syndrome are 1 in 30 or 1 in 4,000. A risk of 1 in 30 means that for every 30 women with this same result, one baby will have Down syndrome and 29 will not. A risk of 1 in 4,000 means that for every 4,000 women with this result, one baby will have it and 3,999 will not. The higher the second number, the lower the risk.


Here is what i found on baby center website. Hope it helps.

Screening tests aren' t perfect. They don' t detect all cases of Down syndrome, so they may identify you as being at low risk when your baby really does have Down syndrome. This is called a false negative result, and it might lead you to decide against diagnostic testing that would have revealed a problem.

Conversely, screening may identify you as being at high risk when your baby is fine (a false positive). This may cause you to undergo further testing and to worry about your baby' s well-being unnecessarily.

How reliable a test is can be seen in its detection rate. The detection rate tells you how good the test is at identifying babies that are truly affected as being high risk. Specifically, it' s the percentage of affected babies who show screen-positive results, out of all those being screened.

The NT scan alone will detect about 70 to 80 percent of babies with Down syndrome (depending on which study you look at). The detection rate for the first-trimester combined screening (the NT scan plus a first-trimester blood test) ranges from 79 to 90 percent.

This means that if you' re carrying a baby with DS, there' s a 79 to 90 percent chance that the combined screening will detect the abnormality and give you what' s called a screen-positive result indicating that further testing is recommended. It also means there' s a 10 to 21 percent chance that the tests will miss the DS and give you a screen-negative result.

This does not mean that a screen-positive baby has a 79 to 90 percent chance of having DS. It just means that 79 to 90 percent of babies who have DS will have screening results that are suspicious enough to recommend diagnostic testing. And 10 to 21 percent of babies who have DS will be determined to be at normal risk — that is, the results will be falsely reassuring.

These tests also have a 5 percent false-positive rate. A false-positive result is one that suggests there may be a problem when, in fact, there is no problem. A 5 percent false-positive rate means that 5 percent of the babies with normal chromosomes who are tested will be screen positive — that is, the test will show them to have an increased risk for Down syndrome even though they' re not affected.

Based on this false-positive result, their mothers may go ahead with invasive diagnostic testing that they otherwise might not have. (And they' ll probably worry more, too, until they know for sure that the baby is fine.)


KR replied. Hi Shruti,

Sorry to hear abt the result. But don' t worry, just wait for the other test to be done as Aparna said. I had the AFP test done today and waiting for he result in abt a week. My Gyn clearly told me several times before the test, that not to worry and panic even if the lab result is negative. Only 1% of women who had abnormal test result will have problems. So just take care of health till then and pray God. I' m sure everything will be alright.

Take care,
KR

Aparna replied. Shruti,

Sorry to hear that but don' t worry. I know its very hard but I think you should go for second opinion.
Mine is scheduled for this friday (27th) also my doc said, if the results are not normal, next step is to go for Amniosentisis (this test is to make sure their diagnosis is correct).
Mean while, pray to god and don' t let your health go down.