Can you get a paternity test while pregnant?

During pregnancy, small pieces of the baby's DNA circulate in the mother's blood. The lab reads them from an ordinary blood sample and compares them with the possible father's DNA. Nothing enters the womb, and DNA Diagnostics Center (DDC) says the test carries no risk to the pregnancy. Two older methods, CVS and amniocentesis, take a sample from inside the womb and carry a small risk of miscarriage.

How early can you get a paternity test while pregnant?

DDC, AlphaBiolabs and the American Pregnancy Association put the earliest point for the blood test at 7 weeks; Cleveland Clinic describes the draw from the eighth week. Weeks are counted from the first day of the last period. Cleveland Clinic notes that you may need an ultrasound first to confirm how far along you are, and GameDay DNA says it confirms this before booking.

How does the non-invasive test work?

1. The mother has blood taken from her arm. DDC says it has more than 3,000 collection sites. With some kits, you arrange the draw yourself at a doctor's office or clinic.
2. The possible father gives a cheek swab. He doesn't need to be at the mother's appointment.
3. The lab picks out the baby's DNA from the mother's blood and compares it with his.
4. The result comes back a few business days after the lab has both samples: in as few as 3 at DDC, 5 at AlphaBiolabs, and 3 to 7 at Choice DNA.

For the full timeline, see how long a paternity test takes.

Is a prenatal paternity test safe?

The non-invasive test is a standard blood draw from the mother's arm. Cleveland Clinic lists its risks as those of any blood test, such as bruising, bleeding or feeling faint. DDC and the American Pregnancy Association say it is safe for the baby.

CVS and amniocentesis are different. A doctor collects cells from the placenta or fluid from around the baby, and both carry a small risk of miscarriage. MedlinePlus, from the National Library of Medicine, puts the risk of miscarriage after CVS at up to 1 in 100 women. The American Pregnancy Association calls both outdated methods for paternity testing.

Is a prenatal paternity test accurate?

Labs report the result the same way as a test after the birth. DDC reports a probability of paternity above 99.9% when the man is the father and 0% when he is not, and Cleveland Clinic describes the test as 99.9% accurate.

It has limits. Most labs can't test a pregnancy with twins or more; DDC, Choice DNA and the American Pregnancy Association all say so. The result also depends on the lab, so ask which lab runs the test and check it on AABB's list of accredited labs.

Personal result or legal result?

A personal result is for your own answer. A legal result needs a witnessed collection, with each person's ID checked and the samples sealed, so that a court or a child support agency can rely on it. DDC and GameDay DNA both sell a legal version of the prenatal test. DDC notes that judges decide what they accept, so if a case is already open, ask what the court needs before you book. You can also test privately now and take a legal test after the birth.

Who has to agree?

The test needs the mother's blood and the possible father's swab, and every adult tested must agree to it. DDC notes that a private test is voluntary, while a judge can order testing in a court case. In Florida, testing someone's DNA without their consent is a crime under section 817.5655 of the state's statutes. If the possible father won't take part, see paternity tests without the father.

To test before the birth, see how the prenatal paternity test works: one blood draw for the mother and a cheek swab for the possible father.

Questions

Can you do a prenatal paternity test at home?

Only partly. Some labs mail a kit, but a health professional still has to draw the mother's blood. GameDay DNA's home kit, for example, needs the draw done at a doctor's office, a clinic or by a mobile phlebotomist.

Does insurance pay for a prenatal paternity test?

Rarely. DDC says health insurers generally treat it as a personal or legal matter.

Can the test be done with twins?

Usually not. DDC and Choice DNA say they can't test a pregnancy with twins or more, so the test waits until after the birth.

Sources

• DNA Diagnostics Center: Non-invasive prenatal paternity testing (dnacenter.com)
• DNA Diagnostics Center: Legal paternity testing (dnacenter.com)
• AlphaBiolabs USA: Prenatal paternity DNA test (alphabiolabsusa.com)
• Choice DNA: Noninvasive prenatal paternity test (choicedna.com)
• GameDay DNA: At-home non-invasive prenatal paternity test kit (gamedaydna.com)
• GameDay DNA: DNA testing FAQs (gamedaydna.com)
• American Pregnancy Association: Non-invasive prenatal paternity test
• Cleveland Clinic: DNA paternity test
• MedlinePlus: Chorionic villus sampling
• MedlinePlus: Amniocentesis
• AABB: Accredited relationship testing facilities
• The Florida Senate: Section 817.5655, Florida Statutes