How is cvs performed

It's a diagnostic test rather than a screening test. That means that it can tell for sure whether a baby will be born with a specific chromosomal disorder. This test is offered to all pregnant women, but in particular those whose babies are at higher risk for a chromosomal abnormality.

These include pregnant women who are older, already have a baby with a chromosomal disorder, or have had an abnormal screening test. The CVS is considered an alternative to an amniocentesis because it can be done earlier in pregnancy, giving expectant parents more time to receive counseling and make decisions.

Unlike amniocentesis, CVS does not provide information on neural tube defects like spina bifida. This takes about two minutes or so. You may feel a strange dragging or drawing sensation in your pelvis or legs - this is normal, and no cause for alarm. It may be necessary to take a second sample. Once the sample is taken, the needles are removed. The baby is checked using the ultrasound scan. You are then free to get dressed. Generally, you can expect to be at the clinic for up to 90 minutes.

Immediately after chorionic villus sampling You may be asked to wait half an hour or so before leaving the clinic, just to make sure that both you and your baby are all right.

It may be best if someone else drives you home, especially if you were given drugs during the test. The placental sample is sent to a laboratory and cultured.

When enough cells have grown, the chromosomes are individually tested to make sure the number, appearance and size are correct. The results are usually sent to your doctor within a few weeks, so make sure you arrange for a follow-up appointment. Self-care after CVS Be guided by your doctor, but general suggestions include: Get plenty of rest for the remainder of the day. Avoid hard physical activity, such as lifting heavy objects. You should be able to go about your normal business in the next day or so.

See your doctor immediately if you notice any unusual vaginal discharge, such as bright red blood or watery fluid. Long term outlook after chorionic villus sampling If CVS shows that your baby has an abnormality, you can undergo counselling if you need help to make a decision.

The cervix is dilated and the contents of the uterus removed. Rarely, your health care provider might caution against transabdominal chorionic villus sampling — which is done through the abdominal wall — if:. Rh sensitization. Chorionic villus sampling might cause some of the baby's blood cells to enter your bloodstream.

If you have Rh negative blood and you haven't developed antibodies to Rh positive blood, you'll be given an injection of a blood product called Rh immune globulin after chorionic villus sampling. This will prevent your body from producing Rh antibodies that can cross the placenta and damage the baby's red blood cells.

A blood test can detect if you've begun to produce antibodies. Some older studies suggested that chorionic villus sampling might cause defects in a baby's fingers or toes. However, the risk appears to be a concern only if the procedure is done before week 10 of pregnancy. You might need to have a full bladder for chorionic villus sampling. Check with your provider about how much fluid you might need to drink, as well as any other pre-test preparation that might be necessary before your appointment.

Your health care provider will explain the procedure and ask you to sign a consent form before the procedure begins. Consider asking someone to accompany you to the appointment for emotional support or to drive you home afterward. Chorionic villus sampling is usually done in an outpatient facility or the health care provider's office. First, your health care provider will use ultrasound to verify your baby's gestational age and the position of the placenta.

You'll lie on your back on an exam table with your abdomen exposed. Your health care provider will apply a special gel to your abdomen, and then use a small device known as an ultrasound transducer to show your baby's position on a monitor.

Next, your health care provider will use the ultrasound image as a guide and take the tissue sample from the placenta while you lie still. This can be done through your cervix transcervical or your abdominal wall transabdominal. This will tell you whether a genetic or chromosomal condition has been discovered. If rarer conditions are also being tested for, it can take 2 to 3 weeks or more for the results to come back. You can usually choose whether to get the results over the phone or during a face-to-face meeting at the hospital or at home.

Find out more about the results of CVS. Page last reviewed: 20 July Next review due: 20 July Your doctor or midwife will tell you about this before you attend your appointment. You can bring a partner, friend or family member for support when you have the test.