Patient Information

If you are a patient seeking an FMF accredited provider near you, please contact Naomi Greene , FMF USA Screening Coordinator by one of the following methods:

  1. Send an e-mail to In the subject line enter "Find me an Accredited Provider". In the body of the e-mail, please include your name, city and state and the distance you would be willing to travel for a Nuchal Translucency ultrasound by an accredited provider.
  2. Send a fax to 818-301-2208 with the same information as above.

You will receive a response within 72 hrs.

First trimester screening for Down syndrome

The vast majority of babies are healthy, but about 1 in 100 are born with a serious mental or physical handicap. One of the commonest conditions is Down syndrome, when the baby receives an extra chromosome 21 (Trisomy 21). It is more common with older mothers, but can occur whatever the age of the mother (see the table below).

Maternal age (yrs)

Chance of Down syndrome

At 12 weeks

At birth


1 in 1070

1 in 1530


1 in 950

1 in 1350


1 in 630

1 in 900


1 in 460

1 in 660


1 in 310

1 in 450


1 in 250

1 in 360


1 in 200

1 in 200


1 in 120

1 in 170


1 in 70

1 in 100


1 in 40

1 in 55


1 in 20

1 in 30

Screening for Down syndrome and diagnostic testing

The only way to be certain whether the fetus has Down syndrome or not is by doing a diagnostic test – an amniocentesis or chorionic villus sampling (CVS). A CVS is performed between 11 and 13+6 weeks and involves taking a small amount of tissue from the placenta; an amniocentesis involves taking fluid from around the baby and is usually done after 15 weeks. Both provide a sample that contains tissue that has the same genetic make-up as the baby and will allow the baby's chromosomes to be looked at in detail. But the problem with these invasive tests is that they can cause a miscarriage, even if the baby is entirely normal. The risk of miscarriage is about 1%.

Therefore the decision as to whether to have an invasive test or not must be taken on the basis of a non-invasive assessment of the likelihood (risk) that the baby has Downs syndrome. The most accurate way of estimating this risk is by combining the information from:

  • The age of the mother
  • The findings from an ultrasound scan at 11-13+6 weeks (the nuchal translucency scan)
  • Information obtained from the levels of certain pregnancy hormones in the mother's blood.

The nuchal scan

The nuchal scan is an ultrasound scan performed between 11 and 13+6 weeks of pregnancy, during which the fluid at the back of the baby's neck (the nuchal translucency) is measured. All babies will have some fluid here, but in babies with Down syndrome the fluid tends to be increased.

  • What else does the scan do?
  • Other things that we can do at the time of the scan are:
  • Confirm your dates
  • Check that the baby is developing normally
  • Diagnose a multiple pregnancy
  • Check the fetal anatomy that is visible at this stage

First trimester serum biochemistry

A blood test taken from the mother can be used to measure the levels of two hormones (free ß -hCG and PAPP-A). In pregnancies affected by Down syndrome there is a tendency for the levels of free ß -hCG to be increased and PAPP-A to be decreased.

The combined first trimester screening test

  • Screening by maternal age alone picks up about 30% of the babies with Down syndrome.
  • Screening by nuchal translucency picks up about 80% of the babies with Down syndrome.
  • Screening by free ß -hCG and PAPP-A picks up about 60% of the babies with Down syndrome.
  • The combination of these three methods is the most effective, picking up about 90% of the babies with Down syndrome.

At the end of the combined screening test you will be given a risk that the baby has Down syndrome; it will not tell you definitely whether or not your baby has Down syndrome, but can be used to help you to make an informed choice about whether to have an invasive test. The wish to proceed to one is a purely personal decision, but as a guide we normally offer an invasive test if the risk of Down syndrome is 1 in 300 or worse. This of course means, that even with a high-risk result most women will still have a completely normal baby.