How we monitor the health of your baby

Easy to understand explanations of screening and diagnostic tests.

All parents want to have a normal baby, but up to 2% of all babies are born with some kind of abnormality. Most are minor, such as fused toes or skin tags. However some babies will have more major problems, such as congenital heart defects, spina bifida and chromosomal irregularities. Antenatal screening and diagnostic tests aim to identify chromosomal or structural concerns. In most cases, we're pleased to say, they provide reassurance that everything's alright.

Routine ultrasound scans

Origins' obstetricians have ultrasound scanners in their surgeries. These are used at most appointments to provide reassurance and check foetal development.

Nuchal translucency ultrasound scan

We like our patients to have a nuchal translucency ultrasound scan. The scan, which is performed at 11 to 13 weeks, can identify up to 75% of Down syndrome babies. It looks specifically for a swelling on the back of the baby's neck - a characteristic of babies with Down syndrome. The result of the scan divides women into two groups - those who are at higher risk of having a baby with Down syndrome and those with a lower risk. Women in the higher risk category are offered an diagnostic test to confirm or exclude the possibility.

Anatomy ultrasound scan

We like all our patients to have an anatomy ultrasound scan. It is performed at 18 to 20 weeks, when the baby is big enough to allow the identification of structural abnormalities. The scan is able to detect 85 - 95% of babies with spina bifida and 50% of babies with congenital heart abnormalities. It will also identify 30 - 40% of babies with Down syndrome. Parents can ask the radiologist to predict the sex of the baby, if they don't want a surprise in the delivery suite.

Chorionic villus sampling

Women over 35 may wish to have chorionic villus sampling (CVS), a test performed at 10 to 12 weeks. It involves removing a small piece of tissue from the developing placenta. This tissue should have the same genetic makeup as the baby. The advantage of CVS is that it can be performed early in pregnancy, however it is associated with a miscarriage rate of 1-2%.

Amniocentesis
Women over 35 may wish to have amniocentesis - a test usually performed at 14 to 16 weeks (it can also be performed at any time after this). Amniocentesis involves removing a sample of amniotic fluid from around the baby. Cells from the fluid are cultured to grow the baby's chromosomes. The advantage of amniocentesis is that it has a miscarriage rate of less than 1%, however it can't be performed as early as CVS.