How much discomfort is involved with CVS?
Most women will feel a slight pressure or even a menstrual-like cramp when a CVS is performed. Afterwards, the discomfort may carry on for another day. Usually taking paracetamol is enough to give relief. Paracetamol is safe to take in pregnancy
Will CVS hurt my baby?
Injury to the baby during CVS is extremely rare. If the procedure is carried out before 10 weeks there is a small risk for problems with the baby’s arms or legs growing. This is not found in babies where the testing has occurred after 10 weeks. Continuous ultrasound monitoring is used during insertion of the CVS needle. Care is taken to avoid placing the needle only in the placenta. The needle does not enter the sac where the baby is found.
What are the problems of CVS?
After CVS, the risk of miscarriage is increased by 1% for the remainder of the pregnancy. Some miscarriages are destined to happen regardless of having the test and a lot fewer are caused by CVS. Generally, the more experience the clinician has, the lower the miscarriage rate will be. In our audited experience, a pregnancy loss caused by a CVS is the same as the fetal medicine centre in London at 1 in 100 tests performed. Sadly, if you were to miscarry this would happen in 50% of cases within the first 2 weeks after the test.
Cramping may occur during CVS and for a short while afterwards. Rarely you may have some blood loss from the vagina. Paracetamol is quite safe to take at this stage of pregnancy. Anything more than mild cramping or spotting should be notified to us or your local medical/midwifery team.
Repeat testing needed
Rarely (less than 1%), the doctor will not be able to obtain sufficient placental tissue or the laboratory test will fail to give a result. This does not mean that something is wrong with you or your baby.
What about the results?
The placental tissue collected is split into 2 portions. One portion is examined very quickly – the short term culture. This result is usually available within 1 to 2 working days after the test is performed. The remaining cells in the other culture are then grown in the laboratory to produce an increased number for examination. This is the long term culture and takes up to 3 weeks to process. We use this second group of cells to be absolutely sure about our initial findings.
If the short term shows no Downs syndrome is present, how accurate is this?
If the result is normal then it is extremely unlikely that the baby has Downs syndrome – less than 1 in 100,000 that the other cells grown in the long term culture will be abnormal. However, there is a small chance that there may be other problems with the chromosomes of clinical significance – about 1 in 500.
If the test results are normal, will my baby be healthy?
There is no test available that absolutely guarantees you will have a healthy baby.
What happens if the test results are abnormal?
Once you have been notified about your test result, a copy will be emailed immediately to you. We will seek your permission to inform your hospital of this result. Your hospital should then contact you to arrange an appointment to discuss your result.
If the short term result is normal how accurate is this?
If the result is normal then it is extremely unlikely – less than 1 in 100,000 that the other cells grown in the long term culture will be abnormal.
Are the results really easy to understand?
Yes as a rule they are. However, occasionally about one in 100 tests show a combination of both normal and abnormal cells. This can be difficult to understand and we need to wait for the second result after 2 to 3 weeks to understand the meaning of this result. Even then it may still be necessary to have another test such as an amniocentesis which purely examines the cells from the baby’s skin or a blood test on your baby. The blood test is where we take some of the baby’s blood from the umbilical cord whilst the baby is still in your womb. Sometimes we have to take blood from both the parents of the baby to see if the finding is due to something inherited from either parent.
Is it possible to tell the sex of the baby?
Yes it is possible to tell the sex of the baby but we will only tell you if you ask us.
Why is it important to know your blood type and Rhesus status?
If you are Rhesus negative you will need to receive a medication called Anti D after the CVS is performed. Anti D is a medication which can prevent the problem of the baby’s blood cells being destroyed by your immune system in future pregnancies. If the baby’s father is also Rh negative, you will not need to receive Anti D. If you are Rh negative, ask your midwife or doctor to supply you with information about what it means to be Rh negative.