Are You Having a Boy or Girl? How to Predict the Sex of Your Baby

It’s normal to be curious about the sex of your baby and want to know as soon as possible. This is so common that there are dozens of folk beliefs, or old wives’ tales, that you can supposedly use to find out. You’ve probably heard of some of them already: having heartburn means it’s a girl, craving salty snacks means it’s a boy, and so on.

Unfortunately, there’s no evidence for most of these beliefs. Your pregnancy symptoms (or the lack thereof) can’t actually tell you the sex of your growing baby.

That’s the bad news. The good news is that there are plenty of legitimate ways to find out. However, they require visiting a doctor’s office and having an actual test done.

In this article, we’ll separate fact from fiction and tell you how you can really determine the sex of your child-to-be.

There are four medical tests that will tell you the sex of your baby. These are the only surefire, evidence-backed ways to find out:

1. Cell-free DNA (cfDNA) prenatal screening test

Available: Week 10 or later

Risks: None

This is a blood test that’s mainly designed to screen for chromosomal abnormalities, such as Down syndrome or Edwards syndrome.

To detect these disorders, the cfDNA test analyzes the fetal DNA that’s present in your own blood. This can reveal the presence of the Y chromosome, which indicates you’re carrying a male fetus (a boy).

Your doctor can perform this test as early as your 10th week of pregnancy. You’ll usually get the results back in 7–10 days.

The cfDNA screening is often recommended for mothers over 35 or who have a family history of chromosomal abnormalities. However, it’s risk-free, so even if your doctor doesn’t suggest it, you can ask for it if you really want to know your baby’s sex (or you want to be extra vigilant about screening for those disorders). Just check whether your insurance will cover the procedure first. 1

2. Amniocentesis

Available: Week 15–20

Risks: Slight risk of complications, including miscarriage

Amniocentesis is another diagnostic procedure that involves taking a sample of amniotic fluid (which surrounds the baby in your uterus) using a thin needle inserted through your abdomen.

This fluid contains fetal cells. As with the cfDNA test, your doctor can analyze these for genetic abnormalities, as well as infections and—you guessed it—your baby’s sex.

While amniocentesis is very accurate, it carries a risk of complications, increasing the rate of miscarriage by approximately 0.5%. 2 Because of this, your doctor will probably only order it if they think there’s reason to be concerned, not just to find out whether you’re having a boy or girl a few weeks earlier than you otherwise would. However, if you have to get the test for other reasons, that’s a nice bonus.

3. Chorionic villus sampling (CVS)

Available: Week 10–13

Risks: Slight risk of complications, including miscarriage

Like amniocentesis, chorionic villus sampling (CVS) involves obtaining a tissue sample for testing. Your doctor will take it from the chorionic villi, which are tiny projections that make up part of your placenta.

This is another test that’s mainly used to screen for chromosomal abnormalities. It’s also similar to amniocentesis in that it carries a small risk of miscarriage, so you shouldn’t get it just to satisfy your curiosity. 2 If your doctor does order it, though, don’t worry—the risks are minor—and as a side benefit, you’ll get extra-early notice about your baby’s gender.

4. Ultrasound (anatomy scan)

Available: Week 18–22 3

Risks: None

An ultrasound uses high-frequency sound waves to create images of your developing fetus. You may get more than one ultrasound over the course of your pregnancy, mainly to assess your baby’s growth and health.

Because ultrasounds create an actual picture of your baby, your sonographer (the ultrasound technician) can also use them to determine your baby’s sex. All they have to do is look for their external genitalia.

Most babies are developed enough for this to be possible between 18 and 22 weeks. The routine ultrasound you’ll have around this time is known as the anatomy scan or the gender scan. Because it’s a nearly universal procedure, this is the most common time when most parents find out their baby’s sex (assuming they want to be told).

Unfortunately, not all babies cooperate during this scan. If yours happens to be positioned in a way that hides their genitalia, you’ll just have to wait until your next ultrasound to find out whether they’re a boy or girl.

If your baby was feeling shy during your last ultrasound and you didn’t get any of the other tests we listed, it makes sense if you’re casting around for other ways to find out if you have a boy or girl.

There are a few pregnancy symptoms that studies suggest might correlate with sex. None have been conclusively studied, and all of the correlations are quite limited. At best, if you have these symptoms, you can take them as mild hints—but don’t get carried away.

5 symptoms potentially associated with carrying a girl

There’s at least some evidence suggesting that if you have these symptoms, you’re more likely to be carrying a daughter.

1. Severe morning sickness (hyperemesis gravidarum)

Many pregnant women experience nausea and vomiting, called morning sickness, in their first trimesters.

The most severe form of this is called hyperemesis gravidarum. It’s characterized by much more intense and persistent vomiting, potentially to the point of requiring treatment.

Some research suggests there’s a link between hyperemesis gravidarum and carrying a female fetus. The theory is that higher levels of the pregnancy hormone hCG, which female fetuses may produce in greater amounts, contribute to more severe nausea. 4 5

2. Cognitive changes / forgetfulness (“pregnancy brain”)

It isn’t just a joke: pregnancy really can lead to forgetfulness, or “pregnancy brain,” which can start as early as the first trimester. Some studies have explored whether this is linked to fetal sex. 6

There might be a correlation between carrying a girl and performing more poorly on certain memory tests. However, the studies investigating this have been small and limited, so as with the other entries in this section, you should take this with a grain of salt.

3. Breech presentation (late pregnancy)

If your baby is in a breech position (feet or buttocks first) late in your pregnancy—after 32 weeks—some studies suggest they might be a little more likely to be a girl. 7

However, many breech babies are also boys, and either way, by the time you reach this point, you’ll probably have found out the sex of your little one through one of your ultrasounds, anyway.

4. Acne

One very small study found a link between acne during the second and third trimesters and carrying a girl. However, even if this holds up, it almost certainly won’t turn out to be a reliable predictor, since hormonal fluctuations may cause acne regardless of your baby’s sex. 8

5. Elevated stress levels at conception

This last one isn’t a “symptom,” but research suggests that higher stress around the time of conception—as measured by your levels of cortisol, a stress hormone—may be linked to a slightly higher chance of conceiving a girl. 9

One theory suggests that female fetuses may be more resilient to stressful prenatal environments, which would make this an evolutionary adaptation. Yet again, the research on this is far from conclusive.

5 symptoms potentially associated with carrying a boy

In a similar vein, these are signs that you could have a baby boy growing inside of you:

1. Food aversions

While many pregnant women find themselves craving certain foods (and sometimes surprising themselves with exactly what they’re hungering for), some also develop the reverse symptom: strong aversions to tastes or smells.

A bit of research suggests that experiencing more intense food aversions might be associated with carrying a boy. The theory is that this is due to your brain trying to protect the more vulnerable male fetus from harmful substances. 10

2. Gestational diabetes

Gestational diabetes is a condition that can develop during pregnancy. It’s characterized by high blood sugar levels.

Some studies have found a tentative correlation between gestational diabetes and carrying a male fetus. 11 If this ends up being true, it’s not clear why that would be the case, although, as with so many things during pregnancy, there’s a good chance it has something to do with hormonal fluctuations.

3. Sleep-disordered breathing

Increased snoring and other forms of sleep-disordered breathing, such as sleep apnea, have been linked in some studies to carrying a boy. One possible explanation involves lower levels of the pregnancy hormone PAPP-A (pregnancy-associated plasma protein A), which has been associated with both male fetuses and sleep issues. 12

4. Eating more / feeling extra hungry

Some studies suggest a link between higher calorie intake (both around the time of conception and throughout your pregnancy) and an increased chance of having a boy. If your pregnancy munchies are particularly strong, you might be a little more likely to have a son than a daughter. 13 14

5. This is your third pregnancy

We’ll cap off this list with another possible correlation that isn’t actually a symptom, per se. One study suggests that third-time mothers may have a slightly higher likelihood of having a boy. Why this would be is anyone’s guess, and in lieu of further research, there’s no way to be sure whether this is a genuine correlation or not. 15

Just to reiterate, everything in this list is a faint association, not a guarantee. What’s more, while each entry is backed by research, they aren’t backed by very much research. If you really want to know the sex of your baby for sure, you’ll have to spring for one of the medical tests we listed further up, or just wait for your next ultrasound.

At last, this brings us to the common myths and old wives’ tales surrounding gender prediction.

Many people believe you can use these signs and methods to tell whether you have a boy or girl. While some of these can be fun, they aren’t supported by any scientific evidence. If you give any of them a try, treat it purely as entertainment.

1. Fetal heart rate

Many people believe that a fetal heart rate below 140 beats per minute indicates you’re having a boy, while a rate above 140 indicates a girl.

However, studies have shown no significant difference in fetal heart rates between male and female fetuses. Normal fetal heart rates fluctuate between 110 and 160 beats per minute, regardless of sex. 16

2. Carrying position (high/low)

There’s another popular idea that carrying “high” (i.e., developing a baby bump higher up on your abdomen) means you have a girl. Of course, the inverse is also supposed to be true: carrying low means you’re having a boy.

This is another myth. The shape and position of your bump are determined by your abdominal muscle tone, the baby’s position in the uterus, your body type, and other boring disappointingly commonplace factors, not the baby’s sex.

3. Linea nigra

The linea nigra is a darkened line that will appear on your abdomen during pregnancy. Some believe that if the line only extends to your navel, you’re pregnant with a girl, whereas if it reaches above the navel, it’s a boy.

Unfortunately, this change in pigmentation is caused by hormonal fluctuations and has nothing to do with your embryo or fetus’s sex.

4. Nipple color

The myth that darker nipples indicate a boy is also unfounded. Whether and how much your nipples darken is caused by your hormonal fluctuations (you’re probably sensing a pattern here) and have nothing to do with sex or gender.

5. Food cravings (sweet/salty)

This is a big one. If you’re particularly craving sweet foods, a lot of people will claim that means you’re having a girl. Craving salty or savory food is supposed to mean the opposite.

It isn’t hard to guess why this is (don’t most people associate sweetness with girls?), but research hasn’t found any correlation between food cravings and fetal sex. That said, your cravings might have something to do with your nutritional needs, so feel free to indulge them, at least in moderation.

6. Cold feet

Some believe that having cold feet during pregnancy means you’re carrying a boy. There’s no scientific basis for this claim, although it’s certainly true that your circulation can change while you’re pregnant, affecting your body temperature.

7. Heartburn

Another old wives’ tale holds that heartburn (acid reflux) during pregnancy means you’re carrying a girl. The idea is that this has something to do with the baby having hair.

In reality, heartburn is mainly caused by your growing uterus pressing on your stomach and hormonal changes relaxing some of your muscles.

It’s actually true that some studies have suggested a link between heartburn severity and your baby having hair when they’re born. 17 Unfortunately, it isn’t true that girl babies are more likely to have a full head of hair in the womb, even if they’re more likely to wear their hair longer later in life.

8. Urine color

The idea that darker urine indicates a girl and lighter urine indicates a boy isn’t true, either. It’s a good idea to pay attention to your urine, but that’s just because darker urine can be a sign of dehydration. If the toilet bowl is more of a caramel than a lemonade color after you pee, that doesn’t mean you’re having a daughter—it just means you need to pound back a couple glasses of water.

9. Chinese birth calendar

The Chinese birth calendar is a chart that claims to predict your child’s sex based on:

• Your age when you conceived
• The month of conception

This method is a folk belief, not a scientific test. If it sounds fun, by all means give it a try, but again, don’t take it too seriously.

10. Other folk beliefs

There’s a handful of other old wives’ tales about figuring out the sex of your baby. You’re supposed to pay attention to:

• Breast symmetry: This consists of checking whether your right breast has swollen more than your left one, or vice versa. (If your right breast has grown more, you’re supposed to be having a girl.)
• Dry hands: Some people also believe that if your hands are dry and in need of lotion, you’re having a boy.
• Mood swings: More intense mood swings are said to mean you’re going to have a daughter.
• The ring test: This consists of dangling a ring over your belly and seeing whether it moves back and forth (meaning you’re carrying a boy) or in a circle (a girl).
• The key test: If you pick up a key, grabbing it by the long end apparently means you’re having a boy. Grabbing the round end means it’s a girl.
• Placenta location: According to the Ramzi theory, if you look at an ultrasound and your placenta is on the right side of your uterus, it means you’re having a boy. If it’s on the left, you’re having a girl.

It probably goes without saying that these myths are exactly that. Again, entertaining them can be fun, but if you take them too seriously, you could be setting yourself up for disappointment.

Just to recap, although some at-home methods of guessing your baby’s sex have more scientific backing than others, there are only four ways that are on really firm footing (and even these aren’t guaranteed to be 100% accurate):

• cfDNA screening
• Amniocentesis
• Chorionic villus sampling
• Ultrasound

These methods become viable toward the end of your first trimester and in the middle of your second. Even if you’re impatient to know—and if you are, you’re in good company!—you won’t have to wait all that long.

Of course, if you decide you’d rather not be told by an ultrasound sonographer or anyone else in a clinical setting, that’s perfectly fine. Many expecting moms ultimately decide to wait and be surprised when their baby finally comes.