Screening for Downs??

**bugalug** · February 16th, 2008, 09:52 AM

Hi all

I'm almost 17 weeks (1st pregnancy, 23 years old), and to date I havn't had any screening for downs or spina bifida. When i went for my 13 week scan the sonographer lady did ask if i was having the nucal translucency, i wasn't as my doctor hadn't specified it on my referral. The sonographer said that it was fine and its up to my doctor.

I have got my referral for my 18-22 weeks scan, and my doctor said this will be a "detailed" scan for any abnormalities, this is specified on my u/s referral. Does this pick up downd syndrome?

Should i be requesting any other screening tests?? Like the blood test that can be done at this time in the pregnancy. I have read so much about the various tests that can be done, and the more i read the more i get confused. Because my doctor hasn't mentioned anything other than this detailed scan, that will test for abnormalities, I didn't think i had to go for additonal tests.....i am now scared that its too late?

Any suggestions as to what is going on, or what i should be doing??

**Rumpleteaser** · February 16th, 2008, 10:08 AM

Being 23, you have one of the lowest risks of having a child with D/S it is something like less than 1:1380. Where are the older you get the risks increase. EG: a 40 yr old would have a 1:130 and at 47yrs, a 1:15 chance.
I don't think a scan at 20 weeks will be able to dectect downs, possibly if you got a 3D/4D scan it might. You have missed the oppertunity for the NT BT which would give you a low or high risk of having a child with D/S. The tests at a later date (where you are) are more invasive and have a higher risk of causing m/c. I would doubt you have much to worry about, giving your age. I'm sure you would have considered the NT test if you had a fmalily history of D/S.
Not sure about scans for spina bifida, it might be able to pick it up? as it might beable to pick up a cleft palete also.

**Mia'sMummy** · February 16th, 2008, 10:59 AM

Our OB said it would be a waste of time testing for downs due to our age, so we didnt bother.

If it is really troubling you, go and see your doctor and say, what are my options at this point?

**fionas** · February 16th, 2008, 11:18 AM

Hi bugalug

It is all very confusing. The 12 week scan SPECIFICALLY checks for Downs because some women (especially older mums like me) are higher risk than younger mums like yourself. As someone has said, you have a pretty low risk on your age alone of having a child with Downs.

Having said that, the 20 week scan will check for physical abnormalities - some of which would be 'fixable' ie. like something wrong with the intestines, heart, lungs etc whereas obviously Downs is something that isn't 'fixable'.

So don't be too freaked out by the word 'abnormalities'.

So at your 20 week scan they won't SPECIFICALLY be checking for Downs whereas they would at the 12 week one by looking at something called the nuchal transparency. Now I don't know whether they can still do this at your 20 week scan if you ask for it or not. Obviously they can take any measurement they like but at 12 weeks they are able to compare what that measurement would be for a child with Downs as opposed to a child without Downs. Later on, perhaps that difference is not as pronounced - not sure.

My ob also told me that if you do have a baby with a chromosomal abnormality like Downs, there is usually some other physical characteristic that is picked up at the 20-week scan that would also be an indication eg. a hole in the heart.

I'm sure it's not too late to run some tests if you are concerned though your risk is low. Perhaps just ring your doctor and have a chat - I know what you mean, sometimes we read too much and we end up more confused!

**Je$$_84** · February 16th, 2008, 12:35 PM

the down syndrome testing (nuchul test) is at 13 weeks. it is a scan that checks the amount of fluid at the base of bubs neck and has to be done around that time as once buibs gets to big it isnt acurate. The only other way you can check is by amneo i think... My GP also never refered me for it this preg and my first. As i am also 23 and chances are slim unless you have family members with downs...

I didnt bother as i couldnt terminate a pregnancy either way... i think its too late to have a screen now but the 18 week one checks for heart problems and clef palete...

**bugalug** · February 17th, 2008, 08:08 AM

Thanks everyone for ur replies....... just wasn't sure what was going on.

It was good to hear ur advice, I think maybe because og my age and that fact we dont have a history of downs my gp didn't worry about testing for downs.

Thanks again to everyone who replied. Feeling much more at ease.

I guess i should just be looking forward to m next scan so i can see bub again!!

**bugalug** · February 17th, 2008, 08:19 AM

I forgot to ask in my previous thread....

When i book my next u/s does it really matter when it is?? Its my 18-22 weeks scan....so does it make a difference if i go when i'm 18 weeks....or wait till 22 weeks??

Just excited to see bub again!!

**Jewel** · February 17th, 2008, 09:01 AM

Hi.

We have our ultrasound booked in for 19wks. I can't wait. It's so excitinggggggg.

I hope you're having a H&H pregnancy!

**Je$$_84** · February 17th, 2008, 01:46 PM

With my 18-20 week scan i went few days after 18 weeks and as my bubs was bit small i had to rebook as the sonographer couldnt complete the test...

I'd recomend waiting til after your 19 weeks just to be safe. we were all excited to find out the sex aswell and couldnt cos we came a bit early... Hope everything goes well...

**HotI** · February 17th, 2008, 05:47 PM

Here is a summary of the tests available

SCREENING TESTS
Nuchal Translucency (NT) ultrasound (11-13 weeks)
**combined with age to give risk for Down Syndrome & Trisomy 18.

1st trimester combined screening-
*blood test (10-12 weeks- max 12 wk 6 days) PLUS
*nuchal translucency (NT) ultrasound (12 weeks)
**combined with age and weight to give risk for Down Syndrome & Trisomy 18.
**blood test must be organised privately (e.g. GP)

2nd Trimester Maternal Serum Screening
*blood test that is usually done 15-17 weeks.
**combined with age and weight to give risk for Down Syndrome, Trisomy 18 and neural tube defects.
** blood test can be organised in public hospital.

Ultrasound at 18-20 weeks
* check internal and external anatomy of baby
* can detect 'soft markers' that may indicate baby has a chromosomal variation. To find out definately, diagnostic test must be performed.

DIAGNOSTIC TESTS
CVS and amnio examine the chromosomes of the baby. They count the chromosomes present and can detect when there is variation from 'normal'. They can also detect with certainty the gender of the baby. Results take approx 2 weeks but preliminary results through a lab procedure called FISH can happen within 2 days. FISH usually costs around $150.

Chorionic Villus Sampling (CVS)
* 11-13 week gestation (12 weeks best)
* 1 in 100 risk of miscarriage (1%)

Amniocentesis
* 15+ week gestation
* 1 in 200 risk of miscarriage (0.5%)

Hi Bugalug

The girls are right, you are in low risk due to your age for having a baby with Down Syndrome.

The 2nd trimester screening test is still available to you if you would like to have it done. You have to think about what the results would mean to you, both low risk and high risk. Or you might be happy to just wait til the 18-20 week scan.

Take care,

Kate

**SarahU** · February 18th, 2008, 05:39 AM

Regarding the downs syndrome question, my doctor also did not send me for the NT scan, however at my 18-20 weeks scan the lady doing the ultrasound said at that stage they can pick up 85% of down syndrome cases.