The test will confirm whether your baby has an abnormality or not. A normal result will put you and your partner’s minds at rest. An abnormal result will tell you if the baby has Down’s syndrome. This would enable you to make a decision to continue with the pregnancy or not.
Are there any alternatives?
We can do an amniocentesis test after 16 weeks gestation of the pregnancy. If you need a test for abnormality earlier than this we would do a chorionic villus sampling (CVS). We can do a CVS any time after 11 weeks gestation.
What if you do nothing?
If you do not have the test you will not know if your baby has an abnormality. If you are in a high-risk group we advise having the test.
The doctor will gently insert the needle through your tummy and into your uterus. S/he will then push the needle into the amniotic sac that surrounds the baby. The amniotic sac also contains the amniotic fluid. A syringe is connected to the needle and a small sample of the amniotic fluid, about 10-15ml, is taken out. We place the sample in the specimen bottle that you previously checked. We send it to the laboratory for testing. The doctor removes the needle and places a dressing over the needle entry site. If you need the Anti-D injection it will be given now. This injection is given into the muscle in your arm, buttock or thigh.
How long does it take?
Including the ultrasound scan, an amniocentesis test takes between 10 and 15 minutes.
Who will be doing it?
An obstetrician will do the test. They may be a specialist in fetal medicine. There will be a consultant obstetrician in charge, but a suitably experienced obstetrician may actually do the procedure. If the consultant is satisfied with the experience of that obstetrician, s/he may not be present during the test. Your regular obstetrician may not do the procedure as some units have an obstetrician that performs all the amniocentesis tests. A sonographer may do the ultrasound scan. A sonographer is a specially trained member of the x-ray staff that does many of the ultrasound scans in the hospital.
Author: Dr. Chineze Otigbah MRCOG. Consultant obstetrician and gynaecologist.
© Dumas Ltd 2006