Find out what blood tests are available and what they may detect.
There are a range of blood tests you can have including:
The Triple or AFP Test
This test is usually offered to women over 35 or those with a higher risk of having a Down’s Syndrome baby.
Carried out at14-20 weeks, it also assesses the risk of a neural tube defect such as spina bifida or anencephaly (when the foetal brain does not develop). The test shows the level of three substances found in the mother’s blood stream: alphafetoprotein (AFP), oestriol, and human chorionic gonadotrophin (HCG). This test alone does not provide a definitive answer but if the result is positive medical professionals consider that you have an increased risk of having a Down’s baby. To diagnose this further you would be offered an invasive test such as amniocentesis or cordocentesis.
Glucose Torlerance Test
This test for diabetes is used for women at risk of diabetes, particularly those who are known to have high blood sugar, sugar in the urine, diabetes in a previous pregnancy, or a large baby.
Usually carried out at 28 weeks, this test measures blood sugar levels. You will be given a high-sugar glucose drink and an hour later blood samples are taken to determine blood sugar levels.
Anyone at risk may ask to be tested however this is only performed with your consent. The test detects the presence of antibodies for the HIV virus. If you test positive, any infections that you develop must be treated carefully. Certain measures are taken at birth to minimise the risk of transmitting the virus to your baby and often a Caesarean section is advised.
Sickle Cell Anaemia Test
Advised for parents with ancestry originating from Africa and the West Indies. The test looks at the type of haemoglobin in your red blood cells and detects sickle cells. If the sickle cell trait is detected, your partner should be treated as well. If he is positive, the baby is at risk of being born with the disease. An amniocentesis or cordocentesis test will confirm this.
Haemoglobin Electrophoresis Test
Advised for parents with ancestry originating from Asia and parts of Africa, this test identifies the different haemoglobins in red blood cells that denote thalassaemia. If the test is positive, the baby may develop the disease. You may become anaemic and require iron and folic acid supplements.
Advised if you have had recent flu-like symptoms and have been in contact with pets and farm animals. It tests for antibodies to toxoplasma in your blood that suggest infection. If it is positive, antibiotics will be advised to treat the baby along with ultrasound scans to see if the baby’s development is being affected.