Tests in Pregnancy Explained
below is a list of the general tests done throughout pregnancy and what each is looking for to help your doctor or midwife provide the best care for you and your baby
Full Blood Count (FBC)
Measures the number and type of the different blood components - red cells, white cells, platelets and haemoglobin. It gives a good indication of your general health, low platelet levels can be an indicator for pre-eclampsia (High Blood Pressure). Typically you will be asked to have this test done as part of the antenatal screening and again at 28 weeks gestation.
Glucose Tolerance Test (GTT)
Diabetes during pregnancy (gestational diabetes) is due to the production of placental hormones. These are a normal part of pregnancy but they can reduce the effect of insulin in the body, in some women this can result in elevated blood glucose. As your baby gets bigger, your body has to produce as much as double to three times the amount of insulin.
Gestational diabetes has no real symptoms, but it poses a threat to the baby and increases the chances of birth complications.Therefore, it is important to test for, diagnose and treat. It affects about 10-20% of women and the risk increases with maternal age.
Many doctors screen all women for gestational diabetes, while some will test those who present a higher risk. It is possible you will be asked to have a GTT between 24-26 weeks. This involves a glucose drink and then two blood tests after to test how quickly the glucose is cleared from the blood.
Urine - protein and glucose
From time to time you will be asked to give a urine sample. These samples are important because they can be tested to monitor glucose and protein levels. High levels of protein in your urine can indicate pre-eclampsia which is a condition that causes blood vessels to leak protein-containing fluid into the tissues of the body. The kidneys are affected and produce urine with a high protein content.
High levels of glucose in the urine may indicate gestational diabetes. this is a temporary form of diabetes that can occur during pregnancy.
Iron level gradually become depleted during pregnancy, making you more susceptible to anaemia. It is important they do not get too low, your body body needs iron to produce haemoglobin, a protein in your red blood cells that carries oxygen around the body, The FBC measures haemoglobin levels.
Another blood test is Iron Studies. This measures the serum iron (the iron in the liquid part of your blood), ferritin (the amount of iron stored in the body) and transferrin (a protein that transports iron to the cell)
This is important vitamin is essential for building strong bones and teeth by helping the body absorb calcium. When you are pregnant, and when breast feeding you need to make especially sure you have adequate supplies to help your growing baby.
Most of our Vitamin D comes from exposure to the sun, and a small amount from food. Your doctor or midwife may suggest supplements. you will have your blood levels tested at the first antenatal visit and repeatedly after that if they are too low.
Infections diseases that normally produce mild symptoms can be a danger to your baby. Many can be prevented from transmission by having treatment before and during the birth. Some of these tests are routine however your doctor may request you have others if you are at a higher risk. Some are only done if you have been exposed to an infection during your pregnancy
At the first antenatal visit your doctor is likely to ask you to have a mid-stream urine test. This is to check for asymptomatic bacteria in the bladder but have not symptoms of infection. This is normally not a problem however in pregnancy, when the hormone progesterone softens the bladder and and the growing baby compresses the bladder so it does not empty the bladder completely, the bacteria can easily grow. Early detection and treatment may prevent the development of acute kidney infection and possible premature labour.
The bacterium that causes Syphilis can live in the body for many years and can easily be passed onto a newborn baby with terrible consequences. As syphilis is highly treatable, transmission to the unborn child can be easily avoided. Testing is a routine part of the antenatal screen and is repeated at 28 weeks if you are at risk.
Varicella (chicken pox)
Your doctor will want to test your immunity to chicken pox. If you have no immunity and come into contact with the virus you can be protected from infection by receiving an injection of of chicken pox immunoglobulinimmunoglobulinglobulin.
If you become infected while pregnant, anotiviral medication can help if you receive it early enough. There is a small risk your baby could develop foetal varicella syndrome (FVS), which can cause abnormalities.
If you develop chicken pox towards the end of your pregnancy or soon after giving birth, your baby could become infected as well.
This disease is now uncommon, its symptoms are mild however it can have can have a devastating effect on the unborn baby. The risks are highest during the first sixteen weeks, this is when your baby can develop serious abnormalities or you could even miscarry. Even if you are among many who have been vaccinated against it, the importance is vital to test for each pregnancy because immunity from vaccination is not as long-lasting as that from the disease itself.
The Royal Australian and Ne Zealand College of Obstetricians and Gynaecologists recommends all pregnant people be offered hepatitis C testing. The risks of passing on the virus from parent to child are low. Currently there is no treatment available to prevent transmission of hepatitis C.
Group B Streptococcus
.This common bacterium lives in the human body. It is found in the gut,rectum and vagina of about 25% of all healthy women. It causes no symptoms and in rare cases is can be passed onto the baby at birth and cause serious illness or even death. If you are a carrier, you can be given intravenous antibiotics at the time of delivery. The test for Group B Streptococcus carriage is performed between 35-37 weeks. This usually means your doctor may ask you to self collect a combined rectal and vaginal swab.
You will be routinely screened to hepatitis B at your first antenatal visit. Some people are chronic hepatitis B sufferers. This means they continue to carry the virus, unlike the majority of people who are able to fight the infection off in about six months. Hepatitis B is highly contagious - if you have it, you can easily pass it onto your baby at the time of delivery. It is important to be tested because if your results are positive you and your baby can be helped. Your baby can be given an injection of hyperimmune hepatitis B immunoglobulin (HepB antibodies) and started on a course of hepatitis B vaccinations soon after birth.
You will be offered HIV screening as part of your first antenatal visit. You may need to think carefully about having the test, especially if you could be at risk. You'll need to be emotionally capable of dealing with the implications of being HIV positive, and ideally have someone to support you. Steps can be taken during pregnancy and during the birth to prevent the virus being transmitted to your baby. A baby has about one in four chances of catching HIV if left without treatment or medical intervention, but transmission can be almost entirely prevented with appropriate interventions.
Influenza in pregnancy
Influenza vaccination during pregnancy should be routine, safety is well established and may prevent serious maternal or infant respiratory illness.
Cytomegalovirus belongs to the herpes family of viruses. Infection may be asymptomatic or may results in mild flu-like symptoms that can last from a few days to a couple of weeks. Normally it is of little consequence however if you are infected for the first time during pregnancy, it can cause some developmental problems for your unborn child. Affected babies may show no symptoms at birth, but hearing, vision, neurological and intellectual disabilities may be detected later in early childhood. CMV is the most common congenital infection in Australia. Good hand hygiene is important in avoiding infection, especially after changing nappies or other activities that lead to contact with saliva or urine.
If you are concerned, or are at risk, your doctor may request a test for gonorrhoea. This is a sexually transmitted infection (STI) the can be quickly and effectively treated with antibiotics. This test involves having a cervical swab or collecting a urine sample.
Toxoplasmosis is a parasitic infection that in Australia is most commonly acquired from raw or under-cooked meat, but is also found in cat faeces (cats can pick this up from eating rodents). Make sure to eat meat that is well cooked during pregnancy and avoid cat litter trays. Toxoplasmosis is a very uncommon infection, but if acquired during pregnancy can result in miscarrige or damage to the baby's nervous system.
Chlamydia is one of the most common STI's among young people, and it is on the increase. If you are at risk being tested while pregnant is important. Clamydia has few symptoms (it can often be mistaken for thrush or cystitis) but it can lead to ectopic pregnancy and subsequent infertility. Your baby can become infected when passing through the birth canal, leading to neonatal chlamydial conjunctivitis and pneumonia
If you have genital herpes, don't be overly alarmed about your baby developing neonatal herpes as the chances are very low. Your baby will acquire your antibodies during pregnancy and have a natural immunity. The greatest risk of neonatal herpes is if you become infected for the first time at, or close to, the time of delivery. If your baby is one of the very few who develops neonatal herpes they will be treated with antiviral medication at birth.
Listeriosis is an infection caused by eating food contaminated with the bacterium listeria monocytogenes. Symptoms will appear about 3 weeks after eating the contaminated food and you may experience only a mild flu-like illness, but the infection could lead to premature delivery, infection of your baby, or even stillbirth.
To avoid infections, always handle food properly and avoid eating raw foods: uncooked meat/vegetables, and chilled 'ready to eat' foods e.g. soft cheese, cold meats, pre-prepared and stored salads.
It is treated with antibiotics and prompt treatment is important to avoid passing the infection to your baby.