How Early You Tell the Gender of a Baby?

Significant research behind gender prediction testing in recent years has shrunk the timeline of when expecting parents can learn if they’re having a boy or girl.

Today, there are various ways to perform a baby gender test, each available at different times along the pregnancy, and each coming with its own set of pros and cons. The established methods include:

  • Ultrasounds at 20 weeks
  • Amniocentesis at 16 weeks
  • Non-Invasive Prenatal Tests (NIPTs) at 12 weeks
  • Early Gender DNA Tests at 8 weeks

Discovering the gender of your baby is a magical moment along the pregnancy journey. For a full rundown of each of these gender prediction methods, read ahead.


In the United States medical system, an anatomy ultrasound is normally scheduled between 18 and 22 weeks. While the purpose of the imaging is to check for the proper development of the fetus, this ultrasound also has the ability to reveal the gender of your baby.

During an ultrasound, the physician will look for anatomical defects, including:

  • Heart defects
  • Spinal cord abnormalities
  • Diaphragm abnormalities
  • Brain defects
  • Limb deformations

How Do Ultrasounds Work?

For an ultrasound procedure, an expecting mom will lie on her back while a technician or physician spreads a conductive gel on her exposed abdomen. The ultrasound machine sends out high-frequency signals through a probe which reverberate through her body. The sound waves then move through and reflect off different organs and fluid. The same probe picks up the reflected signal and digitizes it into an image, where the physician can then anatomically analyze the growing baby.

Ultrasounds as a Gender Predictor Test

Because the baby’s sex organs have started to develop by 20 weeks, this creates the perfect opportunity to learn about the baby’s gender. However, not all ultrasound sessions are successful at this. Here are a few reasons the physician may be unable to determine the gender:

  • Fetal position – If the growing baby has his or her legs closed or blocked from view, the sex organs can’t be properly determined.
  • Quality of picture – There are a number of reasons the quality of the picture could prevent gender prediction—full bladder, BMI of the mother, odd angle, to name a few.
  • Fidgeting baby – Sometimes the baby is camera shy and won’t stop fidgeting during the ultrasound. This will prevent an accurate reading.

It should also be noted that technicians and physicians make mistakes. Many mothers have reported that their ultrasound gender reading was incorrect and only found out weeks before giving birth. If you’re unsure about the physician’s determination, or if they were unable to determine the baby’s gender, a follow-up ultrasound must be scheduled one or two weeks later to try again.


Amniocentesis is an invasive procedure that extracts amniotic fluid and analyzes it for information about the baby’s health. While efficient as a baby gender test, amniocentesis is generally reserved for when other non-invasive tests reveal major chromosomal anomalies, such as Down Syndrome, Patau Syndrome, or Edwards Syndrome.

This confirmation test is done around 16 weeks into pregnancy and will offer direct access to the baby’s DNA and gender.

Downsides of Amniocentesis as a Gender Test

While it would never be a physician’s first inclination to offer amniocentesis as a baby gender test, it will provide these results. Because it is an invasive procedure, the risks must be understood.

  • Miscarriage – During the second trimester, the risk of miscarriage from amniocentesis is between 0.1% and 0.3%. While the percentage is small, that’s still 2 for every 1,000 procedures.
  • Uterine infection – Invasive procedures always carry the risk of infection. Uterine infection can harm the placenta and the proper development of the baby.
  • Needle injury – If the baby moves an arm or leg during the procedure, there is a risk of needle injury. Serious injury is rare but is still possible.

Again, these tests follow NIPT when a high risk for a birth defect was detected.

Non-Invasive Prenatal Testing

NIPT is a screening test for chromosomal abnormalities that can occur around the 12-week mark of a woman’s pregnancy. A physician or phlebotomist will take a blood sample from mom and use it to screen for potential disorders that may affect the life of the child.

The reason this is possible is that when a woman is pregnant, both her DNA and the DNA of her growing baby are present in her bloodstream. Testing this combined DNA can shed light on the chromosomes of the baby, revealing anomalies and gender.

What Are Chromosomes?

At the most basic level, a chromosome is a thread-like structure made up of DNA that holds information about the entire organism. Within every nucleus of every cell in your body, there are 46 chromosomes (or 23 pairs of chromosomes), each holding a different piece of the story.

One pair amongst the 23 is known as the sex chromosomes, and it identifies the gender of a baby.

What Are Chromosomal Abnormalities?

Because cells are constantly dying off, scratched off, etc., they go through a large amount of division and replication. This is one of the most significant duties of chromosomes: to aid in proper cell division. When there’s something wrong with one of the chromosomes, this abnormality is copied and replicated.

In adults, a chromosomal abnormality may lead to a nonfunctional cell, or cancer cell. If this abnormality continues to replicate without being repaired, the cancer will spread.

For growing babies, chromosomal abnormalities represent even greater risks. Because they have so few cells compared to an adult, these abnormalities can have drastic effects throughout their entire body.

Example Chromosomal Abnormalities

An NIPT screens for abnormalities, such as:

  • Down Syndrome – Trisomy 21 (an extra chromosome 21) – Individuals with Down syndrome experience moderate intellectual disability and cognitive delays.
  • Edwards Syndrome – Trisomy 18 (an extra chromosome 18) – This syndrome often results in a slow growth rate. Edwards can cause heart defects and other birth complications.
  • Patau Syndrome – Trisomy 13 (an extra chromosome 13) – Patau Syndrome results in severe intellectual disability and many growth defects, affecting the heart, spinal cord, and eyes. Only 5% to 10% of children with Patau live past their first year.

Because both mother and baby DNA is included in the screening, false positives that can occur. The screening could pick up genetic abnormalities present in the blood that 1) aren’t present in the fetus and 2) haven’t affected the mother’s health.

NIPT as a Gender Predictor Test

Because there are sex chromosomes, an NIPT acts as the perfect gender prediction test. The benefits of using an NIPT to determine gender include:

  • It’s non-invasive by definition – Because a small amount of mom’s blood is used, there’s no potential for harm to the baby.
  • It’s often covered for “high-risk” pregnancies – A pregnancy is considered high risk when the mother is over the age of 35 or if she has preexisting conditions, such as high blood pressure, autoimmune diseases, or diabetes.
  • It identifies common chromosomal abnormalities – While NIPT does not accurately predict all abnormalities, it is considered highly accurate for the three most common syndromes.

Non-invasive prenatal testing does not come without its drawbacks. Here are some of the cons of NIPTs:

  • Tests are only ordered by medical practitioners – This chromosomal test can’t be done at home and must be performed through a medical facility.
  • It is expensive – Out of pocket, these tests can cost upwards of $1,000. Even with insurance, people can still pay up to $200.
    • Your insurance might not cover it – For women under 35, this test is considered “optional,” so they might not cover it. Prenatal testing has led to serious bills in the thousands of dollars with insurance companies claiming that they have no obligation to compensate the policyholder. Although this is not a common occurrence, it’s a potential factor worthy of consideration.
  • It isn’t performed until around 12 weeks – Because both mom and baby’s DNA are in the sample, a larger amount of baby’s DNA must be present for accurate statistical analysis of chromosomal disorders. This requires waiting until the 12th week, when the fetal fraction is high enough to return correct results.

Early Gender DNA Test

Although technically a form of NIPT because it uses information from the baby’s DNA that’s found in mom’s blood, this test’s sole job is to determine the gender of the baby. The early gender test looks for male chromosomes in mom’s blood. If any are found, you can be sure they aren’t coming from the mother. In other words, it’s a boy! If no male chromosomes are found, it’s a girl! Simple enough, right?

At-Home Baby Gender Test

Because this test is only looking for the presence of male chromosomes, it is accurate with a much smaller fetal fraction than the typical NIPT, which is screening for overall chromosomal abnormalities and needs to tease out the difference between mom’s chromosomes and baby’s. This means the DNA-based gender test can be taken as early as 8 weeks into pregnancy.

SneakPeek offers an at-home gender DNA test that is clinically-proven. In published studies, researchers found that the test is 99.1% accurate at 8 weeks into pregnancy.

Additionally, with SneakPeek, you can have your results within 72 hours. That way, you don’t have to wait any extra time before knowing your baby’s gender. And prices are significantly cheaper than an NIPT ordered by a physician—only $79.99.

This Does Not Replace Physician-Based Tests

It’s important to reiterate that the point of going to your physician during your pregnancy goes beyond discovering your baby’s gender. While this might be one of the more exciting pieces of information you receive, there are serious risks that come with not seeing your doctor.

Early gender DNA tests are not meant to replace the screening efforts of physician-ordered NIPTs, nor should they replace ultrasound appointments. Instead, use an at-home baby gender test to get to know your baby before you normally would at the doctor’s office. That way, the planning can begin immediately.

Ready to Know Your Baby’s Gender?

Never before have parents had the power to discover their baby’s gender so early in a pregnancy. And with only a few drops of blood from the mother and no risk to the baby, it’s no wonder parents are raving about the early gender DNA test.

If you’re excited to throw a gender reveal party and don’t want to wait, SneakPeek has you covered.

Learn More


NIH. Chromosomes Fact Sheet.

Mater. Testing for Down syndrome and other chromosome abnormalities.

NIH. What is a high-risk pregnancy?

CBS. Prenatal Testing Leads To Unexpected, Staggering Bills For Some Parents.

Mayo Clinic. Amniocentesis.

International Journal of Pregnancy & Child Birth. Accurate fetal sex determination from maternal blood at 8 weeks gestation.

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