Screening Tests

Chorionic Villus Sampling

Chorionic villi are small thread like projections that make up part of the early placenta. During CVS, small amounts of chorionic villi (about 10 to 15 milligrams) are removed, and the cells are examined for chromosomal abnormalities. CVS is taken from 10 weeks onwards. An ultrasound scan of the fetus is always performed at the same time as CVS .

Nuchal Translucency

Nuchal translucency thickness is the thickness of the black space (fluid) in the neck area of the fetus. Findings in more than 100,000 pregnancies have shown that in most pregnancies some fluid can be seen. However, if there is more than the normal amount, the risk of chromosomal abnormality is increased. A computer programme uses your age and nuchal thickness to calculate an estimate of your specific risk.

Anatomy Scan

The anatomy scan is between 18-20 weeks gestation and will look at how the baby is developing. A systematic examination of the baby looks closely at all limbs, organs such as the heart, brain and kidneys, to check for abnormalities. It also looks at the location of the placenta in the uterus. It may be possible to tell the sex of the baby if all limbs are in a suitable position.

Maternal Serum Testing

The Maternal Serum Test (MST) is a blood test for pregnant women to find out how much risk there is of possible problems with their babies. The blood test will give you an estimate of the chance (known as risk estimate) of a chromosomal abnormality or neural tube defect in your baby. The kind of problems looked for include Spina Bifida and Downs Syndrome