When Can I Find Out My Baby’s Sex?

Every pregnancy is full of questions, and often, one of the first is, when can I find out my baby’s sex? Some parents want to know as soon as they have a positive pregnancy test. Others prefer a surprise on their baby’s birthday.

There are many ways to find out the sex of your baby, but some are more accurate than others. Here’s how and when you can learn the answer to that million-dollar question — is it a boy or a girl?

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When Do You Find Out Sex?

Your baby’s sex is determined at conception when the sperm fertilizes the egg. If you’re having in vitro fertilization (IVF), you may have the option to know the sex of your embryo before it’s implanted. But if you conceived naturally, you’ll have several opportunities to learn whether you’re carrying a boy or girl during your pregnancy.

Your doctor will order various tests to check your baby’s health in the first or second trimester of pregnancy. Most of these tests can also accurately determine your baby’s sex. If you want to know, you can ask your doctor when they receive the test results.

You should also let your health care provider know if you prefer to wait until your baby is born. Otherwise, they might accidentally reveal the sex and spoil your surprise.

Prenatal Screening Tests for Sex

Your prenatal care includes several tests that screen for genetic and other developmental problems that may affect your baby. These tests can also determine your baby’s sex. You may not have all these tests, but you should have at least one.

Non-invasive prenatal test (NIPT)

After ten or eleven weeks, you can have a non-invasive prenatal test (NIPT). This simple blood test screens for genetic or chromosomal abnormalities like Down syndrome. It looks at pieces of DNA from your baby that circulate in your blood.

Besides screening for genetic disorders, this is also an accurate way to determine your baby’s sex. When the lab examines the DNA, they look at your baby’s X and Y chromosomes. Females have two X chromosomes and no Y chromosomes, while males have one X and one Y chromosome.

Doctors routinely order the NIPT test for anyone with a high-risk pregnancy, and many doctors offer it to all pregnant patients. The blood sample comes from the pregnant patient, so there’s no risk to your baby.

Note that this test is accurate if you’re carrying one baby. In this case, the presence of a Y chromosome means the baby is male. The absence of a Y chromosome means the baby is a female.

If you are carrying twins (or more), the test is only accurate if:

  • The test shows no Y chromosomes. This means all the babies are females.
  • You are carrying twins and know they are identical because they share a placenta. (This test can’t tell if your twins are identical or fraternal twins. But an ultrasound scan as early as 11 weeks can show if twins share a placenta.)

Chorionic villus sampling

The chorionic villus sampling (CVS) test is another way to learn your baby’s sex, but it’s an invasive test and not routinely recommended. Your provider might order a CVS test between 10 and 12 weeks if your NIPT screening test is abnormal. You may also have a CVS if you’re at a high risk of having a baby with a genetic abnormality.

With a CVS test, a doctor tests a small piece of your baby’s placenta (called a chorionic villus). They insert a tiny tube into the placenta through your abdomen or cervix to collect the sample. They check your baby’s genes in this sample, so they can also determine your baby’s sex.

Doctors don’t do a CVS test unless it’s necessary because the test carries risks like:

  • Cramping
  • Bleeding
  • Miscarriage
  • Preterm labor


This test is similar to the CVS test, but your doctor samples the amniotic fluid instead of the placenta. They test cells in the amniotic fluid for various proteins and genes to look for potential problems with your baby. When looking at your baby’s genes, they can also tell their sex.

Doctors can do an amniocentesis between weeks 15 and 18 of your pregnancy. This is later than the CVS because you develop amniotic fluid at this time of pregnancy. Like the CVS test, this is an invasive test that is performed by inserting a needle through the abdomen into the pregnancy. This test carries less risks than the CVS but can cause cramping or spotting and an increased risk of a miscarriage. This test is only done when necessary.

The CVS test and amniocentesis can accurately determine each baby’s sex when you’re carrying more than one baby. That’s because each baby has a placenta and amniotic sac, so doctors can test their genes separately. If you only have one placenta or amniotic sac, you have identical (same-sex) twins.

Fetal ultrasound

Most doctors schedule a prenatal ultrasound between 18 and 21 weeks, and this is yet another chance to learn your baby’s sex. During an ultrasound, the technician moves an electronic wand (called a transducer) across your belly. It uses sound waves to create pictures of your baby on a computer screen.

Fetal ultrasounds help identify any abnormalities in your baby’s organs. It’s also a way of measuring the size and monitoring your baby’s growth.

The technician can identify your baby’s sex by looking at their genitals during the ultrasound. However, ultrasounds are not 100% accurate because sometimes the baby is in a position that hides their genitals.

At-home gender prediction tests

Today, there are several at-home tests you can buy at the drugstore to determine your baby’s sex. With these tests, you provide a small blood sample from a finger prick and send it to a lab. Some of these tests claim to accurately predict your baby’s sex by the sixth week of pregnancy.

These are DNA tests similar to the NIPT test, except they don’t screen for any genetic abnormalities. They only test for the presence or absence of the male Y chromosome in your blood.

While there’s no harm in using one of these tests, they’re expensive and less accurate that tests your provider does. Speak to them before you invest in one of these tests.

Can Physical Signs Predict Your Baby’s Sex?

Your family and friends might predict the sex of your baby by looking at you or asking about your pregnancy. Of course, there’s no science (or accuracy) behind these old wives’ tales. But it is fun knowing how they did it back in the day.

Signs you’re carrying a girl supposedly include:

  • Severe morning sickness.
  • Forgetfulness.
  • Carrying your baby high.
  • Craving sugar during your pregnancy.
  • Dull or limp hair.
  • Baby having a fast heartbeat.

And according to old wives’ tales, you’re probably carrying a boy if:

  • You’re much hungrier than usual.
  • You’re carrying your baby low in your belly.
  • Your hair and skin are glowing.
  • Your feet are always cold.

Unfortunately, these old wives’ tales only have a 50% chance of being correct. But if you can’t stand the suspense, it’s nice to know many scientific methods are available and accurate.

Nature. Fetal sex determination in twin pregnancies using non-invasive prenatal testing. LINK

Centers for Disease Control and Prevention. Diagnosis of Birth Defects. LINK

Ultrasound in Obstetrics & Gynecology. ISUOG Practice Guidelines: Role of Ultrasound In Twin Pregnancy. LINK

About UPMC Magee-Womens

Built upon our flagship, UPMC Magee-Womens Hospital in Pittsburgh, and its century-plus history of providing high-quality medical care for people at all stages of life, UPMC Magee-Womens is nationally renowned for its outstanding care for women and their families.

Our Magee-Womens network – from women’s imaging centers and specialty care to outpatient and hospital-based services – provides care throughout Pennsylvania, so the help you need is always close to home. More than 25,000 babies are born at our network hospitals each year, with 10,000 of those babies born at UPMC Magee in Pittsburgh, home to one of the largest NICUs in the country. The Department of Health and Human Services recognizes Magee in Pittsburgh as a National Center of Excellence in Women’s Health; U.S. News & World Report ranks Magee nationally in gynecology. The Magee-Womens Research Institute was the first and is the largest research institute in the U.S. devoted exclusively to women’s health and reproductive biology, with locations in Pittsburgh and Erie.