What’s happening this week
- may be forgetful, feeling what some women call the ‘fog’ of pregnancy
- may find that your breasts have already started making colostrum – the fluid that will sustain your baby in the first few days before the milk comes in
- may have a glucose tolerance test. Some women develop a form of diabetes for the first time during pregnancy. This is known as gestational or pregnancy diabetes. It usually disappears after your baby is born.
- measures about 7 to 10 cm
- is about the size of half a banana
- has unique fingerprints already in place.
As any side effects of early pregnancy start to fade, you can really start to enjoy your pregnancy. Here more tests are explained:
You’ll be asked for a sample of urine at each clinic visit. It’s tested for:
- sugar – If there is more than a trace of sugar, you may be developing pregnancy diabetes and will be given a glucose tolerance test to check
- protein – If there is protein, it may be from vaginal discharge which got mixed into your urine; this happens a lot in pregnancy. However, protein can also be a sign that you have a urinary infection such as cystitis or a kidney problem, which you have been unaware of since before pregnancy. In later pregnancy, if there is protein in your urine and you also have high blood pressure, this could be a first sign of pre-eclampsia, an infection which can cause premature labour (see Week 33).
You will be asked to provide another urine sample, this time from the middle of the stream (a mid-stream specimen of urine, MSU or MSSU). If there is still protein in this urine then the sample will be sent to a laboratory for further tests to find out what the problem is.
Thinking ahead: more blood tests
Screening blood tests give an indication of risk for your baby having spina bifida or Down syndrome, and other rare genetic conditions. These blood tests may not be required in regards to Down syndrome, where Nuchal lucency may be done instead. The tests check the levels of certain ‘risk markers’ in your blood.
The three most commonly tested markers are:
- AFP – Alphafetoprotein, a protein substance produced by your baby.
- hCG – human chorionic gonadotrophin, you may recognise this as the hormone which your pregnancy test detected
- Oestriols – A type of oestrogen hormone produced by your baby and the placenta
The best time for this test is between 15 and 19 weeks of pregnancy when levels are stable. You will probably also be offered the ‘double’ or ‘triple’ test (the more markers used, the more accurate the results):
- Double Test: tests for AFP and hCG
- Triple Test: tests for AFP, hCG, unconjugated oestriols
- Triple Plus: tests for AFP, hCG, oestriols and other markers.
Many factors can affect the results:
- your weight (it’s less accurate if you’re very overweight or underweight)
- race (African-Caribbean women have higher levels of AFP and hCG than Caucasian women)
- carrying twins or more
- insulin-dependent diabetes
- recent vaginal bleeding
- uncertainty about dates.
Age is also taken into account when calculating a woman’s risk of having a baby with Down syndrome, a woman over 40 is at a higher risk.
What to do when you get the results
Remember – these tests cannot tell you if your baby definitely does or doesn’t have a problem. They simply tell you whether there is a high or low chance of a problem. About 1 in 20 mothers having these tests is given a result that her baby is ‘at higher risk’. Most of them will go on to have healthy babies free from problems. But a ‘low risk’ result is no guarantee that your baby does not have a problem, either.
- If you are given a ‘high risk’ result: you could go on to have further tests or do nothing.
- If you are given a ‘low risk’ result: you could do nothing or have further tests, although these are unlikely to be offered by the hospital.