Paternity Test While Pregnant: UK Law Explained
By Part of: Paternity Testing for Custody: Your Complete UK Legal Guide
You can arrange a paternity test while pregnant, and the science behind it is sound. Consent is the part that catches people out. Get that wrong and you commit a criminal offence, whatever the result turns out to say.
This guide covers testing before the baby arrives. So it deals with the blood test from around ten weeks, the two hospital procedures, and the consent rule in the Human Tissue Act 2004. For testing after a birth, read our guide to paternity testing and child arrangements instead.
Nobody plans this conversation. Pregnancy is tiring and uncertain already, and a question over who the father is makes it heavier. Our family law specialists hear it every month, so you are not the first person to ask.
Can you get a paternity test while pregnant?
Yes. A laboratory can compare DNA from about ten weeks of pregnancy, using a blood sample from the pregnant woman and a cheek swab from the man you want to test.
It works because a pregnancy sheds DNA into the mother’s bloodstream. NHS Genomics Education describes non-invasive prenatal testing as screening “using a sample of blood from a pregnant woman”, which examines the cell-free DNA carrying both maternal and placental material. That same cell-free DNA makes a paternity comparison possible without touching the womb.
Two routes exist, though. One needs only a blood sample. The other needs a sample taken from inside the womb, and that one carries a risk to the pregnancy.
What are the two ways to test paternity before the birth?
One route is a blood test from the pregnant woman’s arm, which carries no procedural risk. Another takes a sample from inside the womb, by chorionic villus sampling or amniocentesis, and both of those carry a small chance of miscarriage.
| Route | When in pregnancy | What it involves | Risk to the pregnancy |
|---|---|---|---|
| Blood test (non-invasive) | NHS screening pathways run from 10+0 or 11 weeks | A blood sample from the arm, plus a cheek swab from the man | No procedural risk. NHS Genomics Education notes it “removes the small chance of miscarriage associated with invasive procedures” |
| Chorionic villus sampling | “Usually carried out between the 11th and 14th weeks of pregnancy” | Cells taken from the placenta, by needle through the abdomen or by tube through the cervix | “Less than 1 in 200 for most pregnancies, and at around 1 in 100 for multiple pregnancies” |
| Amniocentesis | “Usually done between 15 and 20 weeks of pregnancy” | A thin needle through the abdomen into the womb, to draw amniotic fluid | “1 in every 200 pregnancies” |
One point about the two hospital procedures matters here. The NHS offers them to look for genetic conditions, not to settle who the father is. So a clinician is unlikely to carry out either one simply to answer that question, and the risk figures above are exactly why.
Is a paternity test while pregnant legal without the other person’s consent?
No. Having someone’s DNA analysed without qualifying consent is a criminal offence under section 45 of the Human Tissue Act 2004, and most consumer pages never mention it.
The wording is strict. A person commits the offence if they have “any bodily material intending— (i) that any human DNA in the material be analysed without qualifying consent, and (ii) that the results of the analysis be used otherwise than for an excepted purpose”. Bodily material means anything from a human body that includes human cells.
Qualifying consent is then defined in Schedule 4. For a living adult the rule is short: “qualifying consent” means his consent. So the man must agree before his own sample goes anywhere near a laboratory. The pregnant woman must agree to hers.
The Human Tissue Authority puts it plainly: “In most cases it is illegal to carry out DNA testing, including paternity testing, without consent.” It adds that members of the public should contact the police if they think the law has been broken.
Why a home kit is not a way round it
Home kits change none of this. The Authority is explicit that “the consent requirements for DIY Paternity testing kits are the same as those for any other kind of DNA analysis”. Buying a kit online is easy, in other words, and it does not move the legal line an inch. A paternity test while pregnant needs two agreements, not one.
The penalty is not nominal either. On conviction on indictment, section 45(3) allows imprisonment for a term not exceeding three years, a fine, or both. On summary conviction it is a fine not exceeding the statutory maximum.
So a sample taken quietly from a toothbrush, a razor or a discarded cup is the one route to leave alone. It risks a prosecution. It also tends to end a family case before that case has properly begun, because the first thing the other side asks is where the sample came from.
Will a court accept a paternity test while pregnant?
Usually not, if it came from a direct-to-consumer “peace of mind” service. Government guidance on getting a DNA test to use in court is blunt: “You must use an accredited testing laboratory. If you do not, the results will not be accepted in court.”
That accreditation sits in statute. Under section 20(1A) of the Family Law Reform Act 1969, tests required by a court direction “may only be carried out by a body which has been accredited for the purposes of this section by— (a) the Lord Chancellor, or (b) a body appointed by him for the purpose”.
Two very different things therefore get called a paternity test. One answers a question for you. The other serves a judge, and it adds identity checks, a tracked sample trail and a report the court can rely on. They are not interchangeable, and you cannot turn a cheap kit into the second kind afterwards.
Can a family court order a test before the birth?
We have found no power that lets a family court direct a test on a pregnancy. Section 20 of the Family Law Reform Act 1969 is written around a person who has already been born.
Read the words. A court may give a direction “in any civil proceedings in which the parentage of any person falls to be determined”, and for “the taking, within a period specified in the direction, of bodily samples”.
Section 21 then handles consent to that sample. A sample may be taken from a child under 16 “if the person who has the care and control of him consents”, or where the court decides it would be in his best interests. Both limbs assume a baby a midwife has already handed to somebody.
The declaration route reads the same way. Under section 55A of the Family Law Act 1986 a person applies for a declaration “as to whether or not a person named in the application is or was the parent of another person so named”. The court only has jurisdiction if one of those named people is domiciled or habitually resident in England and Wales. An unborn baby meets neither test.
In practice, then, the court route opens after the birth. Until then, a prenatal test depends entirely on two adults agreeing to one.
Test now, or wait until the baby is born?
Only two things really decide whether to take a paternity test while pregnant. What you need the answer for, and whether the other person has genuinely agreed.
Work through the two questions below. This page saves nothing, and it sends nothing anywhere.
These signals are about the decision, not about whether you are right to ask. A gap here is a reason to get advice, not a reason to wait in silence.
The calls this cannot make for you
- Whether to test now at all, or put the money towards a court-ready test after the birth.
- How to ask for consent in a way that does not harden into a dispute.
- What to do when a test has already happened and consent is now in doubt.
- When to raise the result, and how, if child arrangements look likely to end up in dispute.
Each of these turns on your own facts, and each is far easier to get right beforehand.
Book a free initial consultation
One of our specialists will give you initial advice on your situation.
What a result before the birth does, and does not, change
A paternity test while pregnant answers one question, and that is worth a great deal. By itself, though, it makes nobody a legal parent and it puts no name on a birth certificate.
Registration is the step that records a father. A birth must be registered within 42 days under section 2 of the Births and Deaths Registration Act 1953, so that deadline arrives quickly once the baby does.
After that, three questions tend to follow, and we cover each one separately:
- Whether the law treats a man as a legal parent, which a court can settle through a declaration of parentage.
- How a court-directed test actually runs once proceedings about a child are under way, which our guide to paternity testing and child arrangements explains.
- How a certificate gets corrected afterwards, covered in removing a name from a birth certificate.
- Where somebody was misled about who the father is, which our guide to paternity fraud deals with.
Waiting is not weakness, in short. Sometimes it is simply the cheaper and safer order to do things in.
What we see in practice
A pattern comes round often enough to be worth describing. A woman is a few months into a pregnancy, a relationship has recently ended, and she wants certainty before anyone registers a birth. She searches for a paternity test while pregnant, orders a kit, then asks her former partner for a swab. He refuses, so she sends something of his instead.
By the time we hear about it, the result is not the problem. The method is. He has worked out what happened, the conversation has turned into an argument about consent rather than about the baby, and the report he was never asked about is now the thing he leads with.
The same thing happens in reverse. A man who doubts he is the father quietly keeps a sample, then finds that his own evidence is what gets scrutinised first.
Almost always, the fix is the dull one. Ask properly, in writing, and explain what the test is for. Where the answer is no, wait and take the court-ready route after the birth. A result nobody can object to is worth far more than a quick one.
Hannah Overton, Complex Children Specialist & Client Support
Frequently asked questions about a paternity test while pregnant
How accurate is a paternity test while pregnant?
Accuracy is a claim for the laboratory to make, and we do not repeat figures we cannot check for ourselves. Ask the laboratory directly, in writing, and ask what accreditation it holds at the same time. For a court, accreditation matters more than any percentage in a brochure, because an unaccredited result is not accepted at all.
Can I test without telling the other person?
No. Analysing DNA without qualifying consent is a criminal offence under section 45 of the Human Tissue Act 2004, and the Human Tissue Authority says most DNA testing without consent is illegal. A paternity test while pregnant is no exception, and the same rule covers home kits. If somebody has already done this, get advice quickly rather than acting on the result.
Does the NHS carry out prenatal paternity testing?
We have found no NHS route for it. The NHS pages on amniocentesis, chorionic villus sampling and non-invasive prenatal testing describe screening for genetic conditions, not establishing who the father is. So a prenatal paternity test is a private arrangement, and the two invasive procedures carry a miscarriage risk that a clinician will weigh carefully.
Can I make him take a test while I am pregnant?
Not before the birth. The court’s power to direct scientific tests under section 20 of the Family Law Reform Act 1969 is framed around a person whose parentage falls to be determined in civil proceedings, and we have found no provision covering a pregnancy. Afterwards a direction becomes possible, and a refusal then carries consequences a judge can take into account.
He used a home kit and I never agreed. What now?
Take advice before you respond to the result. Consent is a legal question here, not just an etiquette one, and the Human Tissue Authority asks people to contact the police where they believe the law has been broken. Keep whatever you have about where the sample came from, and avoid a long argument by message.
What should I do before ordering a paternity test while pregnant?
Decide what the answer is for first. If it is only for you, a private test with everyone’s agreement may be enough. If it could reach a court, use an accredited laboratory and expect the real test to happen after the birth. Either way, settle the consent position before anyone posts a sample.
Considering a paternity test while pregnant? Get the consent position straight first
A result obtained the wrong way can damage your position for years, and it cannot be undone afterwards. Book a free initial consultation and one of our specialists will give you initial advice tailored to your circumstances. It does not include drafting or reviewing documents.
General information about the law in England and Wales, not advice on your circumstances.
