This gives the people at risk of health problems the opportunity to get earlier treatment and make informed decisions about their health.
However, screening tests are not perfect and they can not tell you for certain if you do have a health problem. A screening test will only tell you if you are at high or low risk of the health problem.
It is also possible that you could be told you are at high risk of having a health problem when you do not have one, or that you are low risk when you do have a health problem.
It is important you understand the purpose and possible results of a screening test before you decide whether to have it. It is your decision whether or not to have any of the tests offered to you.
Screening tests during pregnancy and beyond include:
- Routine blood tests at your first appointment which include your blood group and iron levels. All pregnant women are offered testing for hepatitis, HIV and Syphylis.
- Blood testing and ultrasound scanning for Down’s, Edwards and Patau’s syndromes
- A detailed ultrasound scan at around 20 weeks of pregnancy
- A top-to-toe newborn physical examination offered to your baby within 72 hours of birth
- Newborn hearing screening
- Newborn blood spot (sometimes called “the heel prick test”) at around five days after birth
People found to be at high risk of a health problem will often be offered a second test.
This is called a diagnostic test and it can give you a yes or no answer about whether you have a health problem.
Because diagnostic testing can be quite complicated you will receive counselling from the maternity screening team to help you to make a decision about having a diagnostic test.
The screening timeline explains which screening tests will be offered during your pregnancy and after your baby is born.
To give you more information about the screening during pregnancy programme the National Screening Committee has written a booklet explaining the screening tests in detail. Your community midwife will give you a copy of this.
The glucose tolerance test (GTT)
The GTT tests for levels which may suggest that you have Gestational Diabetes (Diabetes related to pregnancy). The GTT itself involves a blood test, after which you will be asked to drink a special glucose drink called polycal. Once you have finished the drink we repeat the blood test after two hours. Then you are able to eat and drink as normal and go home.
Prior to the test we ask that you have nothing to eat or drink from 10pm the night before including chewing gum/mints, though sips of water can be taken with any medication you are taking. Smoking is known to affect the test results so we ask that you refrain from smoking from midnight the night before, and you must ensure you bring your pregnancy notes with you.
Gestational diabetes (GDM) affects between 3-9% of pregnancies. Certain groups of women are more at risk and are offered testing in the form of a glucose tolerance test (GTT) between 24-28 weeks of pregnancy.
Those at risk include:
- Women with a BMI over 30kg/m2
- Women who have had a previous big baby weighing over 4.5kg
- Women who have had gestational diabetes in a previous pregnancy
- Those with a family history of diabetes (first degree relative)
- Women from certain ethnic groups (any patient who is not white European)
- Women with a history of Polycystic ovary syndrome(PCOS)
If you think you are included in any of the above and have not received an appointment for a GTT please inform your community midwife.
Implications of gestational diabetes
Attending for GTT is really important because:
GDM increases the risk of:
Babies born to mothers with gestational diabetes can grow too big which means there is an increased risk of:
- Shoulder dystocia (babies shoulders getting stuck at delivery)
- Instrumental delivery
- Caesarean section
- Hypoglycaemia (low blood sugar) following delivery
- Neonatal unit admission
Postnatally, women who have gestational diabetes are 50% more likely to develop Type 2 diabetes within 5 years following delivery.
Dietary and lifestyle changes are important to reduce the risk of developing type 2 diabetes and follow up testing with the GP is required.
Screening tests for you and your baby
Being screened is entirely your choice. Please ask if there is anything about it that you do not understand.
More information on screening
- More information about the antenatal and newborn screening programmes
- Antenatal results and choices charity website (a charity which helps parents through antenatal screening and its consequences)
- Health talk online website (for information about people’s experiences with health)
- Contact a family charity (who support families with disabled children)