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