As everyone will tell you, having a baby is one of life’s most amazing and enriching experiences. Whether this is your first pregnancy or you’ve done it all before, pathology tests will play a vital role in your care and progress.
Every pregnancy is different. As your pregnancy progresses and your baby develops, you can expect to have some relevant tests which are outlined below. Some will be a matter of routine and others may be suggested if your doctor or midwife thinks they are necessary.
We wish you a happy pregnancy and a safe delivery.
Before getting pregnant
If you are planning a pregnancy, it is a good idea to see your doctor for a health check so you can discuss any potential concerns and have some tests before you begin trying to conceive. Being prepared and knowing what to expect can make all the difference.
Tests from preconception to pregnancy
During your pregnancy you’ll have many tests. The majority take place in the early weeks to establish an overall picture of your health and make sure there is nothing to compromise your baby’s development. Others occur in the second trimester as your baby is growing and placing more demands on your body. Towards the expected date of delivery, there will be more tests to make sure you and your baby are healthy and ready for the birth.
The tests that you have will be recommended by your doctor or midwife and may include many of the tests listed below.
- E/LFT (fasting)
- Full blood count
- Iron studies
- Reproductive carrier sceen
- (CF, SMA & Fragile X) or
- Beacon Expanded Carrier Screen
- Full blood count
- Blood group and antibody testing
- Blood glucose
- Hepatitis B
- Hepatitis C
- Iron studies
- Urine MCS
- Down syndrome screen
- NIPT (from 10 weeks)
- Nuchal translucency ultrasound
- Glucose tolerance test (24-28 weeks)
- Down syndrome screen 2
- NIPT (from 10 weeks) if not already performed during this pregnancy
- Morphology scan
- Full blood count
- Blood group and antibody testing (if Rh negative)
- NIPT (from 10 weeks) if not already performed during this pregnancy
Your tests explained
Mother's health checks
These are important in giving your doctor or midwife a good overall picture of your health.
The 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, including your haemoglobin and platelet levels. Low platelet levels may indicate pre-eclampsia — high blood pressure. You will be asked to have a FBC at your first antenatal visit and again at 28 weeks. You may have another at 36 weeks.
Diabetes during pregnancy (gestational diabetes) is due to the production of placental hormones. These are a normal part of pregnancy but they reduce the effect of insulin. In some women this can result in elevated blood glucose. As your baby gets bigger, your body has to produce as much as two to three times more 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 gestational diabetes. It affects about 10–20% of women and the risk increases with maternal age. Many doctors screen all women for gestational diabetes, while others test only those who are at higher risk. It is possible you will be asked to have a gestational glucose tolerance test between 24 and 26 weeks. This involves having a sugary drink, then a blood test afterwards to find out how quickly the glucose is cleared from the blood.
Iron levels gradually become depleted during pregnancy, making you more susceptible to anaemia. It is important they do not get too low. Your 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 serum iron (the iron in the liquid part of your blood), ferritin (the amount of iron stored in your body) and transferrin (a protein that transports iron to the cells for use).
This 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 comes 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.
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 (sugar) and protein levels. High levels of protein in your urine can indicate pre-eclampsia. Pre-eclampsia 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 in pregnancy. Some doctors and midwives like to test everyone at an early visit; others only test if the patient is at higher risk.
If you are due for a routine CST at some time during your pregnancy, your doctor may suggest having it at your first antenatal visit. This is perfectly safe. Routine CST is only performed on women aged 25 years or older.
Infectious diseases that normally produce only mild symptoms can be a danger to your baby. Many can be prevented from being passed on by having treatment before or during the birth. Some tests for infections are a matter of routine — everyone has them. Others are done only if your doctor or midwife thinks they are necessary. Some tests are done only if you have been exposed to an infection during your pregnancy.
Routine antenatal tests
These tests are routinely requested for every 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 bacteriuria, which is when you have a small amount of bacteria in the bladder but have no symptoms of infection. This is normally not a problem. However, in pregnancy, when the hormone progesterone softens the bladder and the growing baby compresses the bladder so it does not empty completely, bacteria can easily multiply. Early detection and treatment may prevent the development of acute kidney infection and possible premature labour.
This disease is now uncommon; its symptoms are only mild, but it can have a devastating effect on the unborn baby. The risks are highest during the first 16 weeks, when you can miscarry or your baby can develop serious abnormalities. Even if you are among the many women who have been vaccinated, it is important that you are tested at each pregnancy because immunity from vaccination is not as long-lasting as that from the disease itself.
You will be routinely screened for 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 off a hepatitis B infection within about six months. Hepatitis B is highly contagious — if you have it, you can easily pass it on to 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 and started on a course of hepatitis B vaccinations soon after birth.
The bacterium that causes syphilis can live in the body, for many years and may easily be passed on to a newborn baby with terrible consequences. As syphilis is highly treatable, transmission to the unborn child can easily be avoided. Testing is a routine part of the first antenatal screen, and is repeated at 28 weeks if you are at risk.
Tests that may be requested
These tests may be requested if your doctor or midwife thinks they are necessary.
The Royal Australian and New Zealand College of Obstetricians and Gynaecologists recommends all pregnant women be offered hepatitis C testing. The risks of passing on the virus from mother to baby are low. Currently, there is no treatment available to prevent transmission of hepatitis C from mother to baby.
You will be offered HIV screening as part of your first antenatal visit. If you are HIV positive, steps can be taken during pregnancy and birth to prevent the virus being transmitted to your baby. A baby has about a one in four chance of catching HIV from their mother without treatment or medical intervention, but transmission can be almost entirely prevented with appropriate interventions.
Your doctor will want you to have a test to determine your immunity to chicken pox. If you have no immunity and you come into contact with chicken pox, you can be protected from infection by receiving chicken pox antibodies. If you are infected while you are pregnant, antiviral medication can help if you receive it early enough. Please see your doctor if you have any concerns. 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.
This common bacterium lives in the human body. It is found in the gut, rectum and vagina of about 25 per cent of all healthy women. It causes no symptoms; in rare cases it can be passed to 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 and 37 weeks. This usually means your doctor may ask you to self-collect a combined rectal and low vaginal swab.
Other less common tests
Ideally, you should be screened for cytomegalovirus (CMV) and toxoplasmosis before you become pregnant, especially if you are at risk. It is wise to find out as much as you can about these infections, and how best to avoid them.
Cytomegalovirus belongs to the herpes family of viruses. Infection may be asymptomatic or may result in mild flu-like symptoms that last from a few days to a couple of weeks. Normally, it is of little consequence, but if you are infected for the first time during pregnancy, it can cause 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 today. Good hand hygiene is important in avoiding infection, especially after changing nappies, or after other activities that lead to contact with saliva or urine.
Toxoplasmosis is a parasitic infection that, in Australia, is most commonly acquired from raw or undercooked meat, but it is also found in cat poo — cats can pick it up from eating rodents. Make sure that the meat you eat during pregnancy is well cooked. Also, avoid touching kitty litter trays, or at least wear gloves and wash your hands well after handling them. Toxoplasmosis is a very uncommon infection, but if acquired during pregnancy can result in miscarriage or damage to the baby’s nervous system.
If you are at risk
These tests will be requested if your doctor or midwife think you may be at risk.
If you are one of the many women who have genital herpes, do not be overly alarmed about your baby developing neonatal herpes as the chances are very low. Your baby will acquire your antibodies during the 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 medications at birth.
If you are concerned, or if you are at risk, your doctor may request a test for gonorrhoea. This is a sexually transmitted infection (STI) that can be quickly and effectively treated with antibiotics. The test involves having a cervical swab, or collecting a urine sample.
Chlamydia is one of the most common STIs among young people, and it is on the increase. If you are at risk − have had a number of sexual partners — being tested when you are pregnant is important. Chlamydia has few symptoms — it is often 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.
Listeriosis is an infection caused by eating food contaminated with the bacterium Listeria monocytogene. Symptoms will appear about 3 weeks after eating 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 meats and vegetables; and chilled, ready-to-eat foods, including soft cheeses, uncooked smoked seafood, cold cuts of meat, paté, cooked diced chicken, pre-prepared and stored salads, raw seafood, and un-pasteurised dairy products. It is treated with antibiotics and prompt treatment is important to avoid passing the infections to your baby.
Influenza vaccination during pregnancy should be routine; safety is well established and may prevent serious maternal or infant respiratory illness.
Blood group tests
An important three-in-one test that looks at your particular type of blood.
It is important that there is a record of your blood group type in case you need a transfusion during your pregnancy or the birth itself. The four blood groups are A, B, AB and O. The most common blood group is type O.
The blood group test also identifies your Rhesus factor, which is either positive or negative. This refers to a particular antigen (protein) on the surface of red blood cells. There are a number of such antigens but ‘D’ is the antigen that causes the most problems. About 83 per cent of all humans are RhD positive and 17 per cent are RhD negative. If your baby has a positive blood group, and you have a negative blood group, your immune system can develop antibodies.
The RhD negative mother usually has no problems during her first pregnancy. However, after she has given birth, she can develop antibodies when a small number of the baby’s red blood cells leak into the mother’s bloodstream. This is most likely to occur
at delivery, but it can also take place during pregnancy if the placenta is damaged. About one in six RhD negative mothers will develop these antibodies.
This can present problems for subsequent pregnancies as babies may be born with anaemia and jaundice — a condition called haemolytic disease of the newborn or Rhesus disease. Injections of Anti-D immunoglobulin will be given at 28 and 34 weeks to prevent this happening.
RhD immunoglobulin is a sterile solution of antibodies to the RhD factor. It is produced from the blood of voluntary Australian Red Cross blood donors. Very strict controls are applied to the selection of donors and to the method of blood processing.
Understanding how Anti-D works
Anti-D injections to ensure that their babies are protected from haemolytic disease of the new born (see diagram below)
The blood group test also checks for potentially harmful antibodies. With widespread preventive treatment, it is only very rare that the screen returns a positive result. If you have received an injection of Anti-D immunoglobulin within the previous six months, the antibody screen can produce a positive result.
Newborn screening test (NBST)
Your baby will have a screening test when they are about three to five days old. A newborn screening test (NBST) may detect certain rare genetic and congenital disorders. The test requires taking a small drop of blood through a heel prick. The tests performed may vary in different states. If the results are positive, a special feeding formula can be introduced.
Chromosomal & genetic disorders
By far the greatest majority of babies are born healthy and without any problems. However, a few — between two and three per cent — have some type of significant physical or developmental abnormality. Often the cause is unknown, but is thought to be a combination of genetic and environmental factors.