Pregnancy- Down Syndrome

[Annaem]

does anyone have any experiences to share with the Down Syndrome Screening they do during the first trimester ( high risk category)?

[nikki-uk]

My middle son was born with Downs Syndrome - and we had no idea that was coming!!!!

Even though I had the standard 'triple' blood test (also known as the spina bifida blood test) at 16 weeks with him it didn't flag me up as I was only 22 yrs old (age is taken into account to assess risk)

When I fell pregnant with my youngest 2 yrs later we knew the 'triple' blood test wasn't conclusive enough - and I didn't fancy an amniocentisis so we opted for a Open Original Shared Link test (chorionic villous sampling) at 11 weeks.

This confirmed our son didn't have Downs.

Of course testing has probably moved on a bit since then (I had my youngest 12 yrs ago) and reading Open Original Shared Link article it would seem there are newer tests available.

Good Luck

[Suzie-GFfamily]

does anyone have any experiences to share with the Down Syndrome Screening they do during the first trimester ( high risk category)?

I have 3 children- 9 yrs, 6 yrs and 17 months. I had the standard triple screen test with my first, and declined it with my second because I wasn't comfortable with the false positive rate (it was too high for my comfort). However, on the 18 week ultrasound of my 2nd child there were abnormalities in some of her heart valves that were considered to be a "soft" sign for Down's Syndrome. We had some additional ultrasound testing done at 22 weeks and there were no other indications of chromosomal abnormalities that could be detected. It turns out that she didn't have Down's, but we didn't know for sure until after she was born.

We waited several years before having our 3rd child- so I was in a higher risk category (based on my age there was a 1/179 chance that our third child could have Down's). There were some new tests available when I was prenant with our 3rd child. In addition to the triple screen blood test, there was an ultrasound screening test which could detect some physical characteristics more commonly associated with chromosomal abnormalities. We had the testing done- the combination of the ultrasound plus the blood screening had a lower false positive rate than the blood screen alone.

Something important to remember is that the blood test and ultrasound are designed to be "screening" tests- they can't tell whether your developing child has a chromosomal abnormality or not. They'll compare the values they measure to a database of values (measurements that have been collected from other women/fetuses) and do a mathematical test to generate a number representing the probability of your baby having a chromosomal abnormality and/or a neural tube defect. It is safer and more cost effective to do this screening initially, and then women who have screen positive results can be offered additional tests. Some of the additional tests can be less invasive (ultrasounds) or more invasive (amnio), and it will be a personal decision which testing (if any) to have done. The different types of tests can provide different types of answers.

The screening is not perfect- there will be some false positives and some false negatives. If the screening was more accurate, it could be used as a diagnostic tool instead of just a screening tool.

The ultrasound that has been added to the initial screening procedure will measure the translucency of the nuchal fold at the back of the baby's neck. The dating of the pregnancy has to be accurate - the measurement has to be made between 11 and 14 weeks gestation. The thickness of the nuchal fold changes during development, so if the measurement is made outside of the 11-14 week window the measurement is not meaningful (they don't have a database of values to compare the measurement to). Sometimes, the ultrasound technician will also look for anomalies in the nasal bone - there might be anomalies in the nasal bone at this stage in development in babies who have chromosomal abnormalities.

Suzie