Tests in pregnancy
With the numerous tests now available, it’s easier than ever to find out how your unborn baby is progressing…
You’ll be monitored regularly throughout your pregnancy, so you can be reassured that everything is well with your health and your baby’s. There will be antenatal check-ups with your midwife every four weeks up to 28 weeks, every fortnight between 32 and 36 weeks, and then weekly until the birth. As well as antenatal check-ups, you will also have around two ultrasound scans and possibly be offered screening tests to check on any abnormalities with your baby.
Routine antenatal checks
At around 10 to 14 weeks you’ll have a booking-in appointment with your midwife where you’ll be checked for:
Height and weight: Some clinics check height and shoe size, as this can indicate pelvis size. Weight tests are now less common as they’re not an accurate indication of your baby’s growth.
Blood pressure: This will be taken at every visit as any change can be a sign of a complication, such as pre-eclampsia (pregnancy-induced hypertension).
Urine: You’ll be asked to give a sample at every check. Too much protein can mean possible infection or pre-eclampsia, too much sugar or glucose could mean diabetes. The presence of ketones in your urine could show that you’re not eating enough or that you are suffering from morning sickness.
Blood: A blood sample will be taken to establish your blood group, rhesus status, immunity to rubella, sexually transmitted infections, a full blood count, and blood sugar levels.
Feeling your baby: At first, the midwife may not be able to feel where your baby is lying but, as you get bigger, your baby’s position will soon be found.
All about ultrasound
When ultrasound scans are offered depends on where you live and your hospital’s policy:
Six to 12 weeks (early scan): This will only be carried out if your doctor wants to find out how your baby is progressing. Sometimes, to get a clearer picture, this is done with a vaginal ultrasound scanner.
Eleven to 16 weeks (dating scan): This measures your baby’s length to check the exact age. Not all women need this, but many tests (see below) need accurate dating if the results are to be reliable.
Nineteen to 20 weeks (anomaly scan): Your baby’s length and head circumference will be measured to make sure they’re growing properly. All your baby’s organs will be checked and the position of your placenta examined. If it’s low-lying, you’ll be offered further scans to check on the position. It’s also possible to tell the sex of your baby with this scan.
After 20 weeks: You may be offered further scans if you’re expecting more than one baby, if your doctor wants to monitor your baby’s growth, if you experienced bleeding, or if you’ve had any complications.
These tests can identify abnormalities, but some are more accurate than others. You’re likely to be offered one if:
- You’re over 35.
- You have a risk of a genetic illness.
- You come from certain ethnic groups.
These non-invasive tests are designed to highlight which mums are most at risk of carrying a baby with a specific problem, but they can’t prove whether your baby is affected. The following tests are used to screen for Down’s syndrome and other genetic problems and birth defects:
- Nuchal fold.
- Alpha-fetoprotein (AFP).
- Double, triple and quadruple test.
These involve guiding a fine needle through the uterine wall. They carry a small risk of miscarriage (around 1 in 100), although the results are 100% accurate.
- Chorionic villus sampling (CVS), (a sample of cells from the placenta are tested for genetic defects).
- Amniocentesis (a sample of the amniotic fluid is tested for a number of conditions).
- Cordocentesis (examines blood from the fetus to detect fetal abnormalities).
If you or your partner are of African, Asian, Mediterranean or West Indian origin, you may be offered tests for sickle-cell disease, Tay-Sachs disease or thalassaemia.