During your first appointment, your midwife or obstetrician will tell you about an optional blood test. It will only be conducted with your express consent. If you agree to give a blood sample, it will be sent to the laboratory to determine:
• Your blood group: A, B, AB or O.
• Your Rhesus D- and Rhesus c-blood group.
• Whether your blood contains antibodies to foreign blood groups.
• Whether you have been exposed to syphilis, hepatitis B or HIV.
If the blood test reveals any risk, it is often possible to provide treatment during pregnancy to protect your baby. For this reason, the test is offered at the earliest possible moment so that treatment can also be commenced promptly.
Often the laboratory will also be asked to check your blood glucose level and your haemoglobin (Hb) level. If the haemoglobin level is too low, you are suffering from anaemia, which usually responds well to treatment.
Syphilis is a sexually transmitted disease (STD). To ensure that the baby does not become infected, it is important that the disease be detected as early as possible in
the pregnancy. Did the blood test show that you have syphilis? You will be referred to an obstetrician and given a course of antibiotics.
Hepatitis B is an infectious disease which affects the liver. Some people experience no symptoms and are therefore unaware that they are carriers of the hepatitis B virus. The blood test will determine whether you are a hepatitis B carrier. The virus is usually not harmful to your baby’s health during pregnancy, but there is a risk of transmission during childbirth.
If the blood test reveals that you are carrying the hepatitis B-virus, your baby will be given an injection of antibodies soon after birth to protect him or her against the virus. It is also important that your baby builds up immunity to hepatitis B. This is why the baby is immunized. The first immunization takes place shortly after birth, and the next ones will be at the ages of 6 weeks, 3, 4, and 11 months at the child health clinic.
HIV is the virus, which can lead to aids. Thanks to new virus inhibitors, HIV is now a chronic disease. You can contract HIV through unsafe (unprotected) sex with an infected partner, or through contact with infected blood.
If the blood test reveals that you are HIV-positive (you have the virus) you will be referred to a specialized HIV centre. You can pass on the virus to your baby during pregnancy or childbirth, or in your milk during breastfeeding. You can significantly reduce the risk of transmission by taking virus inhibitors during pregnancy. For further information, go to www.soaaids.nl or www.hivnet.org.
Antibodies to foreign blood groups
During pregnancy and childbirth, red blood cells from your baby can enter your own bloodstream. If your child has a different blood group to your own, your body may produce antibodies to this ‘foreign’ blood group. The laboratory can check whether this is the case. It is important to know, since some antibodies can enter the baby’s blood through the umbilical cord and ‘attack’ the baby’s own red blood cells leading to anaemia. The antibodies can also have this effect in subsequent pregnancies. If such antibodies are found, further testing may be necessary. Your midwife or obstetrician will explain what this involves.
Rhesus blood group
Women with either of two specific blood types have a greater likelihood of producing antibodies to other blood groups: those with Rhesus D-negative blood and Rhesus c-negative blood. These women need extra attention during pregnancy. As part of the blood test, the laboratory will therefore also determine your Rhesus D- and Rhesus c-blood group.
Do you have Rhesus D-negative blood?
If you are Rhesus D-negative, your blood will be re-tested for antibodies to foreign blood types in week 27 of your pregnancy. This time, the laboratory will also determine whether your baby is Rhesus D-negative or positive.
If your baby is Rhesus D-positive, there is a chance that your body will produce antibodies against his or her blood. To reduce this chance, you will be given an ‘anti-D’ injection in week 30. This presents absolutely no risk to you or your baby. After delivery, you will be given a further injection. Very occasionally, a third injection is required. Your midwife or obstetrician will tell you if this is the case. If both you and your child are Rhesus D-negative, the injections are not necessary since your body will not produce any antibodies.
Do you have Rhesus c-negative blood?
If you are Rhesus c-negative, it is possible that your body will start to produce antibodies to your child’s blood. This will be investigated by means of a blood test in week 27.
No injection is available to stop you producing these antibodies. Therefore, if such antibodies are found, your midwife or obstetrician will wish to increase their
supervision of your pregnancy, with additional check-ups to ensure that your baby’s health is not at risk.
You can find more information about antibodies at www.rivm.nl/bloedonderzoek-zwangeren.
On this website, under ‘Brochures’, there are also brochures with information about Rhesus D-negative, Rhesus c-negative and blood type antibodies.