When Can You Tell the Sex of the Baby?

Woman getting and ultrasound in pregnancy
Photo © Katrina Wittkamp/Getty Images

From early on in pregnancy, one of the first questions you might have is wondering when can you tell the sex of the baby?


An ultrasound is the least invasive way to find out if you are having a boy or a girl. It is usually done between eighteen and twenty-two weeks of your pregnancy. However, after about the fourteenth week of gestation, you can get a very accurate idea of the girls and boys, the biggest risk is not getting the gestational age correctly identified.

They typically are looking at the direction of the genital tubercle and not actual external genitalia. Prior to mid-pregnancy the baby may not be well enough developed to get an accurate answer with an ultrasound to determine the sex. After the midpoint in pregnancy, the baby is more crowded making it more difficult to get a good view. The mid-pregnancy ultrasound done for the screening of fetal anomalies, and not simply to find out the sex of the baby, is generally the best time to accomplish everything.

Genetic Testing

Amniocentesis and chorionic villus sampling (CVS) are genetic tests that can be used earlier to find out the sex of your baby. You can use these tests starting in the late first trimester and use them throughout the pregnancy for various reasons. These tests are more invasive and can pose health risks to your baby. Though these tests also yield better information, diagnostic information, about genetics.

Many mothers are fearful of using the tests solely for finding out the sex and wrangle with whether they even want to know anything about genetics. This can make it even harder to figure out. The risks of these tests are inherent to the test and have nothing to do with genetics. So your baby may not have any genetics issues and may still miscarry from the test and vice versa.

Ramzi's Method

There is also a new method of finding out the sex that is gaining in popularity, it's called the Ramzi's Method or Ramzi's Readings. This uses ultrasound in early pregnancy, as early as six weeks pregnant, to be able to tell the gender of your baby based on locating the placenta. Most physicians don't offer this per se, but you can certainly ask about it if you are having an ultrasound.

Maternal Blood Screening

There are newer tests available that looks at cell free DNA, like the Harmony and MaterniT21. Most are looking at the baby's cells being shed into mom's bloodstream or urine. The hopes are that these tests can quickly and accurately tell newly expectant parents whether their baby is a boy or a girl, but this is an added benefit, the main use is for screening for genetic issues. While some advocates will claim that this will help with bonding during pregnancy, others worry that gender disappointment may set some mothers and fathers up for depression in pregnancy. These early tests are used not only to find out the sex of the baby but to screen for chromosomal abnormalities, finding out the sex of the baby is just an added bonus. While these tests are available for any pregnant person, many times they are done only if a person is over thirty-five or has a potential issue with genetics that needs screening.

These tests may or may not be paid for by your insurance, be sure to check before agreeing to the tests.

Deciding If You Want to Find Out the Sex of Your Baby

The majority of Americans choose to find out the sex of their baby before birth, but there are still a number of families who opt out of this decision. Some do it for personal reasons and others do it because they don't have the means of getting certain tests or because they were not able to get answers from the tests that they had done. (Think about a baby who is not in a good position to determine the sex of the baby via ultrasound.)

While many Americans don't think about it, finding out the sex of your baby has been banned in other countries.

This is largely for fear of sex selection purposes. So this is not something that everyone has the option of doing.

These tests are typically available only to those who could afford them or have insurance coverage for the tests. It is also important to note that these tests are not for fun, they are for serious issues. Finding out the sex of the baby is relatively new compared to how long people have been having babies. The science was developed to help couples who had sex-linked genetic issues and then spread to be a fun thing for others. The ultrasound is largely about figuring out the health of the baby and not about the sex. This can sometimes put patients at odds with their providers.

We have the technology that is discussed above and many fun games and folklore designed to help us enjoy the art of guessing the sex of our babies, but the folklore is just that, folklore and cannot accurately tell you if you're having a girl or boy.


Cell-free DNA screening for fetal aneuploidy. Committee Opinion No. 640. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;126:e31-7.

Odeh M1, Granin V, Kais M, Ophir E, Bornstein J. Obstet Gynecol Surv. 2009 Jan;64(1):50-7. doi: 10.1097/OGX.0b013e318193299b. Sonographic fetal sex determination.

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