Getting ready to welcome a little one is an exciting time that involves getting clothes and gear, preparing their nursery and planning their arrival. It also often sparks a slew of myths and old wives’ tales about predicting the baby’s biological sex.

While it’s natural to be curious, it’s necessary to separate the fun stories from the actual facts, offering soon-to-be parents some reliable insights should they want to know if they are adding a son or daughter to the family.

The myths

For centuries, people have tried to predict the sex of their baby before birth. However, before science and technology led to more reliable methods – more on that later – parents relied on other ways. These approaches tend to be influenced by the effects of pregnancy on mom, while others are a little more fanciful.

Myth 1: Shape and size of mom’s bump

Stories say a higher and wider bump means the baby is a girl, while a lower one indicates a boy. In reality, the shape of the belly is more about mom’s physique, muscle condition and the baby’s position than predicting the sex.

Myth 2: Cravings

In this one, craving sweets means it’s a girl, and a hankering for savory treats predicts a boy. However, like people, cravings are individual and are likely tied to nutritional needs, hormonal shifts or personal taste, not the baby’s gender.

Myth 3: Baby’s heart rate

Myths say that faster fetal heart rate means it’s a girl, while a slower rate suggests a boy. Fetal heart rates vary widely and depend on factors like the baby’s age and activity level, with no consistent link to gender.

Myth 4: Ring on a string

People who try this swing a ring over the belly – circular motion means a girl, back and forth means a boy. However, this ring dance lacks any scientific basis and is just for fun; it’s not a reliable method.

Myth 5: Morning sickness

While many believe that severe morning sickness is a sign of having a girl, it’s much more complicated than that. Morning sickness severity is influenced by hormonal changes, with no clear link to the baby’s gender.

Myth 6: Carrying high or low

Often it’s believed that carrying high means a girl, while low suggests a boy. How a woman carries her baby is influenced by things like muscle tone and baby position, not the gender.

The facts

In reality, none of these can accurately predict the biological sex of a baby.

“They might be fun, but they’re not reliable,” Kelly San Miguel, MD, an OB-GYN in our Greenville market, says.

The baby’s sex is determined the two chromosomes they receive at conception – one from the egg and the other from the sperm that is able to fertilize the egg. All eggs have an X chromosome, but sperm have either an X or Y chromosome. The XX or XY chromosome combination is what ultimately determines a baby’s biological sex.

OB-GYN providers mainly rely on two methods to identify the biological sex of the baby during pregnancy – testing and ultrasound.

• Non-invasive prenatal testing (NIPT): A blood test performed during pregnancy that screens for several genetic conditions, this comes from fetal DNA that is released from the placenta into a pregnant women’s bloodstream. NIPT does not screen for all genetic conditions, and can be drawn as early as 10 weeks into pregnancy. It’s considered between 98 and 99 percent accurate at determining a baby’s sex.
• Invasive testing: These tests are to determine whether a baby has a genetic disorder or a chromosomal abnormality. Women who aren’t at increased risk of genetic and chromosomal problems don’t typically have CVS or an amniocentesis, in part because these tests are invasive and may carry a small risk of miscarriage.
• Ultrasound: If they choose to find out, many pregnant women find out their baby’s sex during their mid-pregnancy ultrasound, which is usually done between 18 and 22 weeks. Ultrasound can be between 95 to 99 percent accurate in determining sex, depending on when it’s done, how skilled the sonographer is and whether baby is in the right position.

“From that first positive pregnancy test, virtually every expecting mom wonders whether they’re having a girl or a boy,” Dr. San Miguel says. “Sex prediction myths persist because sometimes they can appear to be right. When you’re looking at 50/50 odds, predictions are bound to come true half the time. I always recommend to my patients make sure you know the source of what you’re paying attention to.”

Learn about the maternity care services we provide at Bon Secours.