Getting a DNA test for a baby typically involves a simple cheek swab, but the exact process depends on why you need the test and whether the results need to hold up in court. You can test a baby’s DNA before or after birth, at home or through a professional collection site, with results usually available within a few days to two weeks.
Decide What Kind of Test You Need
The reason for the test shapes everything else: where you go, how much you pay, and how the sample gets collected. Most parents looking into DNA testing for a baby fall into one of three categories.
Paternity testing is the most common reason. This confirms whether a specific person is the biological father. You can do this before or after the baby is born.
Ancestry or genetic trait testing is offered by consumer companies like AncestryDNA and 23andMe. These kits require a saliva sample, which can be tricky with a newborn. AncestryDNA allows a parent or legal guardian to activate a kit and submit a saliva sample for their minor child, but the child needs to be old enough to produce enough saliva for the collection tube. Many parents wait until the child is a toddler for practical reasons.
Newborn medical screening is a separate process entirely. Almost every baby born in the United States already receives a state-mandated blood test within 48 hours of birth. A small blood sample is taken from the baby’s heel and screened for up to 50 inherited conditions. This is not the same as a paternity or ancestry test, and you generally don’t need to request it. It happens automatically, though consent rules vary by state.
Testing Before the Baby Is Born
If you want paternity results during pregnancy, non-invasive prenatal paternity testing (sometimes called NIPP) is the safest option. The test works by analyzing fragments of fetal DNA that circulate in the mother’s bloodstream. These fragments can be detected as early as the sixth or seventh week of pregnancy, though most providers recommend waiting until at least the eighth or ninth week for reliable results.
The mother gives a standard blood draw, and the potential father provides a cheek swab. No needle goes near the baby or the uterus, so there’s no risk of miscarriage. Accuracy is high: studies consistently show paternity probability results between 99.9% and 99.9999% when sufficient fetal DNA is present in the sample. In rare cases, the test may be inconclusive if the fetal DNA concentration is too low, which sometimes happens with very early testing.
Older prenatal methods like amniocentesis and chorionic villus sampling (CVS) can also be used for paternity testing, but they carry a small risk of complications and are typically only performed when there’s a separate medical reason for the procedure. Results from these invasive tests can take several weeks.
Testing After the Baby Is Born
Postnatal DNA testing is straightforward. The standard method is a buccal swab: a soft swab is rubbed along the inside of the baby’s cheek to collect cells. It’s painless and takes about 30 seconds. You’ll also need a cheek swab from the parent being tested. Some providers can use umbilical cord blood collected at birth, but cheek swabs are far more common.
One important detail if you’re testing a breastfed newborn: wait at least 60 minutes after feeding before collecting the swab. Research on nursing newborns found that nearly half of cheek swabs taken within five minutes of breastfeeding contained the mother’s cells, which can contaminate the sample. At 60 minutes post-feeding, contamination dropped to less than 7%. This applies to bottle-fed babies with breast milk as well. Formula-fed babies don’t have this issue, but most labs recommend a 30-minute window after any feeding just to keep the sample clean.
At-Home Tests vs. Legal Tests
This distinction matters more than most people realize. The DNA analysis is identical in both cases, but how the sample is collected determines whether anyone beyond you will accept the results.
At-home (peace of mind) tests let you collect samples yourself at home using a kit mailed to you. You swab the baby’s cheek, swab the parent’s cheek, and mail both samples back to the lab. Results typically arrive within one to two weeks. These tests are cheaper and completely private, but they are not admissible in court. No one verified who the samples actually came from.
Legal tests require what’s called chain of custody. This means a neutral third party, usually a trained collector at an approved facility, verifies everyone’s identity with photo ID, witnesses the sample collection, photographs participants, and seals the samples with tamper-evident packaging. The documentation follows the samples to the lab and stays on file. This is the version you need for child support cases, custody disputes, Social Security benefits, immigration applications, or updating a birth certificate. Labcorp and other major testing companies operate collection sites across the country specifically for this purpose.
If there’s any chance you’ll need the results for a legal purpose, start with a legal test. You cannot upgrade a home test to a legal one after the fact.
State Laws That May Affect You
Most states allow you to order a DNA test directly, but New York is a notable exception. New York State requires that DNA tests be ordered by an authorized source: a physician, attorney, or certain government agencies. Private individuals cannot order tests on their own in New York. If you live there, you’ll need to go through your doctor or a lawyer to get the process started.
A few other states have specific consent or notification requirements, particularly when testing a minor child. If you’re the legal parent or guardian, you can generally authorize testing for your baby in all states. If you’re not the legal guardian, such as a grandparent or other relative seeking a test, the rules get more complicated and may require court involvement.
How Long Results Take
Standard lab-processed paternity tests return results in a few business days to two weeks, depending on the provider. At-home kits tend toward the longer end because of mailing time. Some labs offer expedited processing for an additional fee, with same-day or next-day turnaround once the sample reaches the lab. Prenatal tests using amniocentesis or CVS can take several weeks due to the additional processing required.
Results for paternity tests are reported as either an exclusion (the tested person is not the biological father, with 100% certainty) or an inclusion (the tested person is not excluded as the father, typically with a probability of 99.99% or higher). No test reports exactly 100% for inclusion, but anything above 99% is considered definitive.
What the Process Looks Like Step by Step
For a legal paternity test after the baby is born, expect this general sequence:
- Choose a provider. Look for an accredited lab. AABB accreditation is the standard for relationship testing in the United States.
- Schedule a collection appointment. Both the baby and the parent being tested will need to visit an approved collection site. Some providers offer mobile collectors who come to your home or hospital, which is helpful right after birth.
- Bring identification. The parent will need a government-issued photo ID. For the baby, a birth certificate or hospital birth record works. The collector will photograph both participants.
- Sample collection. The collector swabs the inside of each person’s cheek. For newborns, make sure the baby hasn’t been fed in the last hour.
- Wait for results. The lab processes the samples, and results are mailed or made available online, typically within five to seven business days.
For an at-home test, the process is simpler: order a kit, follow the instructions to swab both participants at home, and mail the samples back in the prepaid packaging. Results arrive by mail or through an online portal.
Cost Ranges
At-home paternity test kits sold in drugstores or online typically cost $30 to $90 for the kit itself, plus a lab processing fee of $100 to $200 when you send in the samples. Legal paternity tests with chain-of-custody collection generally run $300 to $500 total. Non-invasive prenatal paternity tests are the most expensive, usually between $1,000 and $2,000, because the lab work is more complex. Insurance does not typically cover elective paternity or ancestry testing, though court-ordered tests may have different payment arrangements depending on your jurisdiction.