Tests and treatment you may be offered

Ultrasound will tell us a lot about your baby, but cannot always make a full diagnosis, so we may offer you additional tests if these might help you in the management of your pregnancy and you choose to accept them.

Diagnostic tests

We may test your baby in several different ways to make a diagnosis.

Ultrasound scans are used to see how a baby is growing and developing and to find out if there are any abnormalities.

Amniocentesis is a way of looking at a baby's chromosomes or DNA to check for some genetic defects. Doctors use a fine needle to extract a small amount of fluid from the sac that surrounds the baby in the womb, which is sent to a laboratory to be studied.

Amniocentesis is usually performed after 16 weeks of pregnancy. It carries a small risk of causing a miscarriage – about 0.5 to 1%. Find out more by reading our amniocentesis leaflet.

Chorionic villus sampling also allows doctors to study a baby's chromosomes or DNA to check for some genetic defects. Doctors use a fine needle to remove some cells from the placenta, which are sent to a laboratory to be tested.

It is usually performed at 11 weeks. It carries a risk of causing a miscarriage - about 2%.

Find out more by reading our chorionic villus sampling leaflet.

Fetal blood sampling is normally reserved for babies and pregnancies that are high risk of particular problems. It involves removing blood from the umbilical cord while the baby is still in the womb. Doctors use the blood to test for problems such as anaemia and infections, as well as chromosome and genetic abnormalities. It is usually performed after 20 weeks.

Fetal cardiology scanning takes place when doctors suspect there might be a heart problem with a baby, or if there is a history of babies born with heart defects in the family. Scans are performed by a fetal medicine consultant and a paediatric cardiology consultant.

They examine the baby's heart in detail, but also examine the rest of the baby's body.

If the scan shows a problem, you will be able to speak to a paediatric cardiology consultant about possible treatment after birth. You will also have a chance to visit the cardiac unit where your baby may be cared for after it is born.


As a specialist centre we can perform rare tests such as fetal blood transfusion and other invasive procedures. These would be discussed if required.

Fetal blood transfusion is where doctors insert a needle through the mother's abdominal wall and into the baby's umbilical cord to give the baby a blood transfusion before it is born.

Intrauterine fetal chest drain can be used in very rare cases where there is extra fluid in the baby's chest to allow the lungs to develop before birth.

Intrauterine bladder drain are very occasionally used to empty a baby's bladder before birth if there is a bladder obstruction.

Intrauterine drug administration may be used to allow the doctors to give a baby medication before it is even born. For example, if the baby has an irregular heartbeat and is ill as a result, doctors can inject a drug into the umbilical cord to make their heartbeat more regular.