TESTS, what are they for, what do they mean
I have had a number of questions recently related to test results and what it means so I thought I would put together a brief outline of some of the test that you may encounter and what these tests look for.
I am sure that I will have missed some tests out so if you can think of anything you would like me to add to this list let me know. When it is complete and if Kelly agrees we could perhaps put this document in the articles list here on BB
URINE
Most of you will have had, at some time during your pregnancy, a urine test. Some of you will have this test at every visit.
How is it done
A small plastic strip with adsorbent pads on it is dipped into the urine sample. Each one of these pads is impregnated with a different chemical which will change colour in the presence of certain products/hormones/elements.
What are we looking for
Protein
Most people will tell you how many plusses (+) are in your urine. The normal value should be nil, however it is acceptable to have 1+ providing that there is no other clinical signs of any problems. More than 1+ could indicate that you are getting pre-eclampsia.
Glucose
Usually measured in small medium or large. Normally there should be no glucose in your urine. A small amount of glucose on the odd occasion is not necessarily a bad thing but it often means that they will do a blood test just to be sure.
Specific Gravity (SG)
The SG measures the amount of impurities in your urine and thus indicates if you are dehydrated. Dehydration can be a major problem in the first trimester due to morning sickness. Often you feel too sick to eat or drink and the act of vomiting causes you to loose more of your body fluids. Some women may be admitted to hospital for a few days and be given fluid by a drip. A SG reading of 1000-1020 is ok the higher the reading the more dehydrated you are.
BLOOD
There are a myriad of blood test that can be performed on a pregnant woman. I will just list a few of the more common ones here but I am happy to add any others that you request
How id it done
Most blood tests are done by inserting a needle into a vein than drawing some blood. For some tests we can just ***** your finger and take a drop of blood from there
Haemoglobin (Hb)
This test measurers your bloods ability to carry oxygen around your body. The Norman level of Hb is 12-15 (120-150) for women and a little higher for men. Often during pregnancy it can get down as low as 10 (100). If it was to drop much lower than this it could mean a blood transfusion.
Blood group
Everyone is probably familiar with the blood groups A, B, AB, and O. Most people would know that these blood groups can be either negative or positive, known as the rhesus factor. There are two main reasons that we need to know your blood group.
1 If an emergency occurs that requires you to need a blood transfusion. Although we can give O negative blood to any other blood type it is far better to give you your own blood type
2 If you are rhesus negative and your unborn baby is rhesus positive then you will need to be given an injection of Anti D. The problem that is caused by the mother being negative and the baby being positive is that should any of the baby’s blood get into the mothers blood stream mum’s body will detect this strange new blood and consider it is being invaded by a virus or infection. Your body will then try to attack and destroy this baby and any other babies that you may carry.
Many other tests are performed on your blood including previous exposure to/immunisation for infectious diseases such as rubella, HIV, hepatitis B and C
ULTRASOUND
A lot of information can be gained from an ultrasound. A few of the more common ones are to confirm pregnancy, check that the baby is head down check that the baby is growing well, and to look at the baby’s organs.
A few other tests that people may have heard of but not know what they are follows below.
Amniotic Fluid Index. (AFI)
This test estimates the amount of fluid in your uterus. A normal reading should be between 5 and 25. The amount of fluid decreases a little after about 37 weeks.
Biophysical Profile (BPP)
This test looks at a number of other tests and indicates the general health of the baby. The score should be above 5
Crown Rump Length. Crown Heal length (CR) (CH)
This test measurers the length of your baby from the top of its head to its bottom (CR) in the first half of pregnancy then from the top of its head to it’s heal in the latter half of pregnancy. This test is often used to estimate the date that your baby will be born. The accuracy will vary through out your pregnancy but is most accurate before 10 weeks where the date can be out by 1 week either way. Later in your pregnancy the accuracy drops even more and can be out by 2 weeks or even more either way.
OK this is starting to get a bit long so I will stop for now. Let me know what other tests that you would like to know about and I will put them all together and submit it to Kelly for inclusion in her list of articles
