How to Tell If You're Having a BoyIf you’re expecting a baby, you probably have heard just about every wives’ tale on how to tell if you’re having a boy or girl. Your mom, your grandmother, your aunts all have tricks they claim can tell you what you will be having.

Many old wive’s tale claims have been made to tell the sex of a baby like how your baby bump is shaped, if you’re carrying low or high, food cravings and heart rate. Scientifically, each pregnancy and baby is unique regardless of their sex. Some say that boys have a slower heart rate and girls are a little faster, but it has been found that no matter the sex of the baby the heart rate goes up and down throughout pregnancy.

There are some pretty accurate ways to tell the sex of your baby, usually by visual or lab testing methods.

How to Tell If You’re Having a Boy or Girl Accurately

Ultrasound Test

If you really want to know how to tell if you are having a boy or girl, you will need to either have an ultrasound, chorionic villous sampling (CVS) or an amniocentesis. While amniocentesis and CVS are not routine tests in pregnancy, ultrasounds are usually done in the beginning of pregnancy and around 16 to 20 weeks gestation. At this time, your baby’s genitals may be formed enough to tell the sex if your baby is laying right. This may still be a bit early, however.

The sexual organs on your baby start to develop at around 6 week’s gestation. Still, they are too small to see or differentiate boys from girls at this time. Even at around 14 weeks, you may not be able to tell exactly. Around the 18th week of gestation, the genitals are usually mature enough to see. Keep in mind that even ultrasound is not 100% accurate and there have been some cases of people buying boy clothes, only to find out they have a girl and vice versa.

CVS, Amniocentesis and Others

The only 99% accurate test for finding out if you’re having a boy is either an amniocentesis or CVS. These tests are very seldom done because they are invasive. They are done to check for abnormalities in the baby’s chromosomes such as Down syndrome or other genetic defects. It involves taking a sample of the baby’s amniotic fluid with a needle and has a risk of miscarriage.

These tests are only done if you are at high risk for genetic defects or have had other positive tests that show your baby may have a problem. Sometimes amniocentesis is done to check the development of your baby’s lungs if he or she needs to be delivered early.

Chorionic villous sampling is normally performed at 11 to 12 weeks gestation. Amniocentesis is done at 16 to 22 weeks gestation and if you want to know your baby’s sex, you can ask your doctor to tell you.

In the future, blood testing may be able to tell you the sex of your baby. There are some labs out of the country that are performing a cell-free fetal DNA test, that can take your blood and look for the chromosome that tells the sex of the baby.

A study from August 2011 that was reported in the Journal of the American Medical Association found that the cell-free DNA test is about 98.8 percent accurate in telling the sex of a boy fetus and 94.8 percent accurate for a girl fetus. Researchers found this non-invasive test to be very low-risk to mother and baby and can tell the sex in early pregnancy. The only problem they found was if couples were unhappy with the results they may possibly look for pregnancy termination.

Situations Where They Will Not Likely to Tell You Sex of Your Baby

Lastly, there are some medical facilities that choose not to let you know what you’re having because the rate of accuracy on ultrasound is not always positive. Medical facilities also worry that disappointed parents may ask to terminate the pregnancy over the sex of their baby. If you are having gas on the day of your ultrasound or you have excessive abdominal fat, your medical facility may choose not to disclose your baby’s sex due to a high rate of error with those situations. Sometimes facilities like to just focus on your baby being healthy.