Finding Out Your Baby’s Sex: NIPT, the Anatomy Scan, and Private Scans Compared

One of the most fun questions in pregnancy is also one of the simplest to ask and surprisingly layered to answer: are you having a boy or a girl? Maybe you want to know the moment it is possible. Maybe you love the idea of waiting until birth. Either way, you have options, and they differ in timing, accuracy, and cost. Here is a warm, plain-language guide to the three most common ways to find out your baby’s sex, so you can choose the path that feels right for you and your family.

NIPT: a blood test that screens first, and reports sex as a bonus

NIPT stands for non-invasive prenatal testing. It is a simple blood draw from your arm, usually offered from about 10 weeks of pregnancy. The test looks at small fragments of your baby’s DNA that circulate in your blood, and its main job is to screen for certain chromosomal conditions, such as Down syndrome.

Because the test reads chromosome information, it can also report whether your baby is likely a boy or a girl. That part is genuinely a bonus. It is worth remembering that NIPT is a screening test, not a diagnosis, so any result that flags a possible condition is typically confirmed with further testing. For sex, the prediction is very accurate when the test runs successfully, though no test is flawless.

The 20-week anatomy scan: the most common reveal moment

The anatomy scan, often called the 20-week scan, is a detailed ultrasound done somewhere around 18 to 22 weeks. Its real purpose is to check how your baby is growing and developing, from the heart and brain to the spine and limbs. For most families, it is also the moment they find out the sex, if they choose to.

This scan is usually part of standard prenatal care, which makes it a no-extra-cost option for many people. Accuracy is high, but it depends on the view. If your baby is curled up, facing away, or simply not cooperating, the sonographer may not get a clear look. You can learn more in our guide to the 20-week anatomy scan and what to expect during this part of the second trimester.

Private early gender scans: paying for an earlier peek

If you do not want to wait until 20 weeks and NIPT is not on your path, private clinics often offer early gender scans, frequently from around 16 weeks. These are ultrasound appointments focused mainly on sex determination rather than a full medical check.

Accuracy varies. The earlier the scan and the less experienced the provider, the more room there is for an unclear or mistaken read. Later scans and skilled sonographers tend to be more reliable. If you go this route, treat it as an extra rather than a replacement for the medical scans your provider recommends.

How the methods compare

Method	Earliest timing	Accuracy	Notes
NIPT blood test	About 10 weeks	Very high for sex	Primarily screens for chromosomal conditions; sex is reported as an extra.
Anatomy scan	About 18 to 22 weeks	High	Usually part of standard care; baby’s position can hide the view.
Private early gender scan	Often around 16 weeks	Varies by timing and provider	Optional extra; earlier scans can be less reliable.

When results are not clear cut

Even with good tools, things are not always tidy. On an ultrasound, a baby who is tucked, turned, or wiggling can keep the answer a mystery. With NIPT, a test can occasionally come back without a clear result and may need to be repeated. None of this means anything is wrong. It simply means biology does not always reveal itself on the first try, and a little patience usually sorts it out.

It is also worth holding these findings gently. What a test or scan shows is your baby’s sex, the physical and chromosomal characteristics. Gender, meaning who your child comes to know themselves to be, is a separate thing that unfolds over the years ahead.

Cost considerations

Money matters, so it helps to know roughly what each path involves. The anatomy scan is usually included as part of standard prenatal care, which makes it the most budget-friendly way to find out. NIPT, on the other hand, may or may not be covered depending on your insurance, your medical history, and where you live, and it can carry a cost. Private gender scans are an out-of-pocket extra by design. If cost is a factor, ask your provider what is covered before booking anything, and check pricing with any private clinic in advance.

Keeping it a surprise or sharing the news

There is no wrong choice here. Some families love the anticipation of waiting until the delivery room, and you can absolutely ask your sonographer to keep the sex to themselves. If you want a surprise but your partner does not, the team can write the result down for one of you, or tuck it into a sealed envelope.

If you would rather share, the options are delightful: a quiet moment between the two of you, a phone call to grandparents, a note slipped into a card, or a small gathering to open that sealed envelope together. However you mark it, the way you find out can become a sweet memory all its own. For more on how this fits into your trimesters, see our pregnancy week by week guide.

Medical disclaimer: This article is for general educational purposes only and is not medical advice. It does not replace care from a doctor, midwife, or other qualified professional. Always speak with a healthcare provider about testing and scans. If you think you may be experiencing a medical emergency, contact your local emergency services right away.

Sources

• American College of Obstetricians and Gynecologists. “Cell-free DNA Prenatal Screening Test.” 2024.
• National Health Service (UK). “Screening for Down’s, Edwards’ and Patau’s syndromes.” 2024.
• Mayo Clinic. “Fetal ultrasound.” 2024.
• Society for Maternal-Fetal Medicine. “Prenatal Screening for Fetal Aneuploidy.” 2024.