Sample collection
Chorionic Villus Sampling
Chorionic villus Sampling (CVS) involves taking a sample of the placenta. A sample is usually taken between 11 and 13 weeks of pregnancy. Using ultrasound guidance, a needle is passed through the abdomen or the cervix (in a procedure rather like a pap smear), and a small piece of the placenta is removed and sent for testing; see Prenatal chromosome abnormality testing. Only a specialist with sufficient sampling experience should perform this procedure. This procedure has approximately a 1 in 100 chance of causing miscarriage but in good hands will be less.
Source: NSW Genetics Education prenatal diagnosis booklet (from Vogel F & Motulsky AG, 1986, Human Genetics, 2nd edition, Springer-Verlag, Berlin)
Amniocentesis
A sample of the fluid surrounding the baby is taken from the amniotic sac which contains cells from the baby. A sample is usually taken from 15 weeks onwards in the 2nd trimester of pregnancy. Using ultrasound guidance, a needle is passed through the abdomen and ~20mL of fluid is removed and sent for testing; see Prenatal chromosome abnormality testing. Only a specialist with sufficient sampling experience should perform this procedure. This procedure has approximately a 1 in 200 chance of causing miscarriage but in good hands will be less.
Source: NSW Genetics Education prenatal diagnosis booklet (from Vogel F & Motulsky AG, 1986, Human Genetics, 2nd edition, Springer-Verlag, Berlin)
Blood
A 5-10ml sample of blood is taken from a vein, usually from the arm.
Miscarriage or pregnancy tissue
Your doctor can send to us a sample of the miscarried products or curettings.
If you’re experiencing a miscarriage at home and you’re in a situation where you can collect the products that were miscarried, we may be able to test the sample for chromosome abnormalities. The success will depend entirely on the condition of the sample when we receive it. The sample should be collected in a sterile, or near as clean as can be, container and preferably wetted with sterile saline. Contact the lab immediately to arrange how to get the sample to us, see Contact us.
Buccal or mouth swab
A sample from the inside of the cheek is taken using a mouthswab which is shaped like a tiny brush. The brush is rubbed up and down, firmly, against the inside of both cheeks 15 to 20 times to obtain cell material for DNA extraction. The sampling procedure is painless.