112 Harley Street
What is a paternity test?
A prenatal paternity test is a diagnostic genetic test to determine the father of your unborn child.
The samples are gathered using either a CVS from 12 to 14 weeks or an amniocentesis procedure from 16 weeks gestation onwards and by taking a blood sample from yourself and the presumed father(s). The samples are analysed in a genetic laboratory using forensic technology to produce a result that will either include or exclude a potential father. Where a DNA sample has been taken from the mother, potential father(s), and the unborn child the probability of paternity is 99.99% accurate or greater. Like any medical procedure there is a risk. With prenatal paternity testing the risk of miscarriage is 1% when the test is performed by a CVS and 0.5% when by an amniocentesis.
How are the samples taken?
The sample from the mother is taken by a consultant fetal medicine specialist. Blood samples from the father(s) are taken by a certified medical professional at The Doctors Laboratory (TDL) close by to the clinic. If the potential father lives overseas it is still possible to have the test however UK legislation requires that the samples be taken by a registered professional. We can send a collection kit to a nominated GP, doctor or nurse who has agreed to take the sample.
When can’t the prenatal paternity test be performed?
In 5% of patients we are unable to perform a CVS due to the position of the placenta. The only solution is to wait until at least 16 weeks when an amniocentesis can be performed. We also don’t usually perform the test between 20 and 34 weeks due to the risk of the procedure triggering premature labour.
Can you test the paternity of twins?
Yes, it is possible, however the chances of having separate pregnancies from two different fathers are extremely rare and so testing just the one fetus is enough in most cases.
What happens with my results?
Your results will be sent to you by mail in 5 working days in an unmarked envelope. Alternatively, you may receive your results by calling the laboratory and using a pre-agreed security password.
Legally any potential fathers participating in the test must give their written consent beforehand. If there are two potential fathers at least one must consent and participate in the test. If there are three potential fathers, then at least two must participate and so on. All our staff are bound by our company’s patient confidentiality agreement. Only the people who give samples (or their nominated solicitor) will be able to receive a copy of our report. Please be aware that neither the London Women’s Clinic nor any associated clinics involved in collecting samples are willing or able to provide representation in a court of law.
Can you test for anything else at the same time?
We are able to offer testing for many genetic disorders at the same time as your prenatal paternity test (additional lab fees apply), using the same samples. For instance, you may have had a high-risk result from your Down’s Syndrome screening or are simply seeking reassurance that all is well with your baby.
Pregnancy and Gynaecology
112 Harley Street