Amniocentesis is a time honoured method of taking fluid from the sac that the baby is in, during its time in the womb. The fluid is called the amniotic fluid and contains many things of interest. Included are skin cells that the baby sheds from which we can determine the genetic detail of the baby. In addition it contains chemicals like bilirubin that also can provide details of the health of the baby.
Amniocentesis can be done for a variety of reasons including:
- Confirming the baby’s genetic make up
- Checking for infection in the womb
- Checking the bilirubin levels for monitoring of babies with isoimmunisation problems
- Checking for baby lung maturity
These days the main use will be for checking for the baby’s genetics. The rest are mainly historical although they can still be used under certain circumstances. In genetics, the amniocentesis will give the definitive result required.
Undertaking an amniocentesis is not difficult. It involves inserting a needle under ultrasound guidance, through the mother’s tummy, into the womb and the baby’s sac. Then a small sample of fluid is removed. In most, it takes only a few minutes to do with minimal discomfort experienced by the mother. This is performed in the ultrasound department and there is no need for hospitalisation. It is usually undertaken when the pregnancy is 15 weeks or more. This is because the amount of amniotic fluid is sufficient to obtain. However, in certain cases, it may be performed earlier providing there is enough fluid.
There is a risk associated with the amniocentesis of miscarriage. This is low in the order of 1 in 200 but may be higher depending on the circumstance and stage of the pregnancy. Causes of miscarriage can include:
- Rupture of the membrane
Following an amniocentesis, it would be prudent to avoid strenuous activity for 24 hours. One should monitor for vaginal loss of clear fluid or bleeding. Increasing or excessive lower tummy pain or a fever may also indicate the beginnings of an infection or early labour. Most cases of complications will occur in the first 48 hours though it can be as late as 10 days later. Should you have any concern, you should contact your obstetrician, the doctor who undertook the amniocentesis or the midwife at the Maternity Unit of the Hospital that you are booked at.
When an amniocentesis is considered, then the risk of the procedure will need to be weighed against the benefit of the information obtained.
These notes reflect my personal opinion and are intended for general advice only. It should not be used for any one individual case. You should consult your own doctor to determine the appropriate management of your own individual situation.