Screening Tests

When women become pregnant they can go through some very mixed emotions. First time mothers-to-be find many of these emotions are due to uncertainty about what the next nine months will entail and whether or not they will be able to 'handle it'. Let me say from the outset that you will be fine. It might not always be a walk in the park but we are women and this is what we do.

What to expect at first

The first hurdle is visiting the antenatal clinic for the first time. You arrive with your appointment letter in your hand, book yourself in and join the many other women in the waiting room, some obviously pregnant and some not so, and wait until it is your turn to be called. It is then that you find out what the maternity team do to make sure that you have a normal, healthy pregnancy and that at the end of it all you have a perfect, healthy little baby.

The antenatal care is designed to spot any problems that may develop as soon as possible and deal with them; to ensure you understand the changes that will occur within your body during pregnancy; and ultimately to make sure that you know how to look after your baby once it is born. Several things will happen on your first visit:

1. The midwife will take a full medical history from you, asking questions about your health and the health of your family as well as questions about whether or not there is a history of particular medical conditions in your or your partner's family.
2. You will be given a full examination. They will take your height and weight and blood pressure, examine your abdomen and possibly also perform a vaginal examination.
3. You will be asked for a urine sample which will be checked for protein (albumin), sugar and the presence of organisms.
4. You will have blood taken to find out your:

• blood group and rhesus status
• Rubella antibody status
• Syphilis, Hepatitis B and HIV status

They will also take blood to:

• perform an alpha-fetoprotein test
• check for anaemia
• screen for any other blood disorders

These screening tests are carried out during the first three months of your pregnancy as this is the time when the baby's organs and structures are formed. It is important there are no infections or conditions present that can interfere with the baby's development.

What else happens during screening tests?

The maternity team use your height and weight to monitor your progress and try to prevent you from gaining excessive amounts of weight during your pregnancy. Your weight will increase naturally as your baby develops and grows, but excessive weight gain can affect your health and may be more difficult to lose after the birth. To make sure that you stay healthy during the nine months you should eat healthily and take regular exercise.

The urine is tested for the presence of protein which can indicate a urinary tract infection or that you are developing a condition called pre-eclampsia. Pre-eclampsia can occur in a few pregnant women and if it is not detected early it can be life threatening.

Blood pressure is checked so that any changes in blood pressure are detected and investigated. During the middle of the pregnancy it is common to feel odd or light headed when you stand up. This is because blood pressure can be lower than normal at this time although some women can develop a condition known as 'pregnancy-induced hypertension' towards the end of the pregnancy, which may not be detected without regular monitoring.

The medical team needs to know what your blood group and rhesus status is. Some women are rhesus negative which is not usually a problem during the first pregnancy, but could be an issue during subsequent pregnancies if the father is rhesus positive. Treatment is available to help this once the team know the mother's rhesus status.

Screening for diseases

Rubella, or 'German Measles', immunisations are offered to teenage girls while they are still at school. The immunisation programme was started to protect any future children the girls may have. Catching rubella during the early stages of a pregnancy can have serious consequences for the baby. There are options, which the midwife or doctor will discuss with you, for if you are found to have no immunity at all or if your levels are low.

Sexually transmitted infections such as syphilis are sometimes asymptomatic, so you may not know that you have it. They can sometimes cause miscarriages or stillbirths if not diagnosed and treated. Hepatitis B is a virus that affects the liver, causing serious disease. Some people can become carriers of this virus. If you should become infected while you are pregnant it may also infect your baby, increasing its chances of developing serious liver disease in adulthood. If it is detected, your baby can be immunised as soon as it is born and you will be referred for specialist help.

Hepatitis C can also cause serious liver disease and is not usually included in the antenatal screen, but if you suspect that you may be at risk speak to your midwife who will be able to help you.

Human Immunodeficiency Virus or HIV infections can be passed on to a baby during pregnancy, the birth or while breastfeeding. The Department of Health recommends that all pregnant women are screened for HIV and that it is offered at the antenatal clinic. Testing is confidential and help is available for you and to reduce the risk to your baby, should the test be positive.

If your tests for anaemia show that you are anaemic you will be given iron tablets and folic acid to boost your levels. Anaemia will make you feel very tired during the pregnancy and could mean that you may have difficulties after giving birth if you lose a lot of blood.

Subsequent visits

On all your subsequent visits to the antenatal clinic the maternity team will continue to monitor you and your baby with regular urine tests, weight and blood pressure checks for the reasons mentioned above. During the course of the pregnancy, be sure to raise any concerns you may have with your midwife or doctor. It is possible that you may come into contact with or catch any of the infections mentioned above while you are pregnant. Always remember that your health and the health of your baby are paramount.

Along with all the tests mentioned you will have at least two ultrasound scans during the pregnancy, one between eight and 14 weeks and the other between 18 and 20 weeks. The scan uses sound waves to produce a picture of the baby in the womb and it will not harm you or your baby. During the scan they will check:

1. The size of your baby, giving you a more accurate due date. This is useful if you are not sure of the date of your last period.
2. The number of babies you are carrying.
3. Whether the baby is developing normally or if there are any obvious abnormalities present.
4. Where the placenta is in relation to your baby. If it is situated low down in the womb it might mean that you need a caesarean section to deliver your baby safely.

The first scan is usually used to give you more accurate dates, while the second concentrates more on the baby's development and the presence of any abnormal features. There are other, more specialised screening tests available for genetic conditions such as Down's syndrome. These tests involve a blood test and a specialised ultrasound scan and will be offered between 11 and 20 weeks. You do not have to have these tests if you do not want them. A negative test cannot categorically rule out Down's syndrome. A positive screening test is not definitive; it means there is a possibility that the child you are carrying has Down's syndrome but other tests will be needed to confirm the diagnosis.

Whatever tests you undergo during your pregnancy, remember they are there to protect you and your baby from what may be a small risk of things going wrong. Most women sail through their pregnancies and have perfectly gorgeous babies. The screening tests are there to reassure you that all is going well and that if there is something slightly awry it will be picked up and put right.