When Should You Consider a Prenatal (Before Birth) Paternity Test?

| October 21, 2025

Deciding whether to do a paternity test before your baby is born is a deeply personal choice. There are options, risks, and practical considerations to weigh but knowing your choices and what to expect can help you make an informed decision.

Prenatal Paternity Testing: The Options

There are generally three main types of prenatal paternity tests:

  1. Noninvasive Prenatal Paternity Test (NIPP / cell-free fetal DNA test)
    This is the safest option. It relies on analyzing small fragments of fetal DNA (called cell-free fetal DNA, or cffDNA) that circulate in the mother’s bloodstream. A blood sample is drawn from the pregnant woman, and a cheek swab or blood sample is taken from the alleged father. The lab isolates the fetal DNA and compares genetic markers. Because this method doesn’t involve inserting any instrument into the uterus or disturbing the fetus, there’s no risk of miscarriage associated with the testing itself. Many providers consider this safe.
  2. Chorionic Villus Sampling (CVS)
    This is an invasive procedure done in the first trimester (typically around weeks 10–13). A tiny sample of placental tissue (chorionic villi) is collected via catheter through the cervix or via needle through the abdomen. That tissue contains fetal DNA, which is then compared to the alleged father’s DNA. Because it is invasive, CVS carries a small risk of miscarriage, usually quoted between about 0.5% to 1%.
  3. Amniocentesis
    Performed later in the pregnancy in the second trimester (around 15–20 weeks) an amniocentesis collects fetal cells from the amniotic fluid using a thin needle through the abdomen. The fetal cells are analyzed and compared. Like CVS, it is invasive and involves a small risk of miscarriage or other complications.

Timing: When Can You Test?

  • Noninvasive test (cffDNA-based): Many labs offer noninvasive prenatal paternity testing as early as 7–10 weeks of pregnancy, though the test is more reliable after 10 weeks when there is more fetal DNA present in the mother’s blood.
  • CVS: Usually done between 10–13 weeks gestation.
  • Amniocentesis: Usually offered between 15–20 weeks of pregnancy (sometimes a bit earlier or later, depending on provider).

Because in early pregnancy the proportion of fetal DNA in maternal blood is lower, very early noninvasive tests may sometimes yield inconclusive results or a false negative (i.e. not enough fetal DNA to make a determination).

Accuracy & Limitations

  • Noninvasive (cffDNA) testing can reach 99.9% accuracy in many cases when sufficient fetal DNA is available and quality controls are strict.
  • Some scientific studies have shown very high rates of correct paternity exclusion and inclusion (e.g. 99.95% for exclusion) in large cohorts.
  • However, there is a potential for false negatives or inconclusive results if fetal DNA concentration is too low, contamination, or technical issues.
  • Invasive tests like CVS and amniocentesis generally have very high accuracy because they use direct fetal tissue or cells, but their risk makes them less desirable just for paternity testing alone.

Also, noninvasive prenatal tests may not be admissible in court in many jurisdictions unless they meet specific legal protocols (chain-of-custody, accredited labs, etc.). Always check local laws and consult a legal or family law professional.

Risks & Ethical Considerations

  • With the noninvasive test, the physical risk is extremely low (just a blood draw) — the main risks are emotional (unexpected results) and confidentiality or privacy issues.
  • With CVS and amniocentesis, the risks include miscarriage (though rare), bleeding, infection, or other complications. Because these are medical procedures, they require qualified medical providers and risk disclosures.
  • Ethically, revealing non-paternity during pregnancy can be emotionally charged. Some medical practitioners recommend pre-test counseling so that both parties understand the possible outcomes and how results will (or won’t) be shared.
  • In some cases, medical ethics guidelines or institutional policies may prefer to notify only the mother or not disclose paternity outcomes without consent.

What to Expect: The Process

Here’s what someone considering prenatal paternity testing can generally expect:

  1. Consultation / counseling
    Before testing, many providers will review your medical history, explain the risks, help set expectations, and get informed consent.
  2. Sample collection
    • For a noninvasive test: a blood draw from the mother, and a cheek swab or other DNA sample from the alleged father.
    • For CVS or amniocentesis: invasive collection by a medical specialist using ultrasound guidance.
  3. Laboratory analysis
    The lab isolates fetal DNA (in noninvasive) or uses collected fetal/placental cells (in invasive). They amplify specific genetic markers and compare them to the alleged father’s DNA profile.
  4. Quality control & confirmation
    Labs must check for contamination, low DNA quantity, or genetic anomalies. Sometimes retesting or further analysis is needed.
  5. Report
    You will receive a paternity probability (e.g. “99.9% match” if positive, or “0%” if excluded). Some labs also provide a paternity index or explanatory notes.
  6. Post-test counseling / steps
    Depending on results, you may want legal advice, emotional support, or further confirmatory testing (e.g. after birth).

Turnaround time varies depending on the method, lab capacity, and confirmatory needs — it may take from a week up to several weeks.

When It Makes Sense

You might consider a prenatal paternity test if:

  • You want clarity before birth for emotional, medical, or legal planning
  • There is a dispute or uncertainty about biological parentage
  • You anticipate needing to resolve custody or support issues quickly
  • You want to bond or plan early with certainty

That said, some choose to wait until after birth to avoid medical risks or reduce emotional pressure.

How DNAPaternityTestingCenters Can Help

At DNAPaternityTestingCenters.com, we specialize in connecting clients with certified labs that offer noninvasive prenatal paternity testing, as well as legal postnatal testing when needed. We guide you from consultation to sample collection, manage chain-of-custody protocols, and help interpret results in a compassionate, confidential manner.

If you’re considering a prenatal paternity test and want to understand your options, risks, or legal implications or get started with a certified provider or contact us today. Our team is ready to help you make an informed choice with confidence.