Boy or girl? Debunking baby gender prediction myths

For as long as humans have been having babies, we’ve been fascinated by the question: is it a boy or a girl?

Before modern-day scientific advancements, the only way to find out was to wait until the baby arrived. In the meantime, families would often turn to old wives’ tales or traditional beliefs in the hope of getting an early indication, from how the baby bump looked to the types of food the expectant mother was craving.

Today, we’re fortunate to have access to DNA testing that can give us answers much earlier in pregnancy. Yet despite these advances, many gender prediction myths continue to circulate.

While these stories can be fun to explore, it’s important to remember that relying on them too heavily can lead to confusion or disappointment if the reality turns out to be different.

Here, we take a closer look at some of the most common myths about predicting gender and explain how a simple DNA test can provide certainty, long before the baby is born.

When is a baby’s sex determined?

Although it might not be visible on an early scan, a baby’s biological sex is determined from the moment of conception.

Every person inherits 46 chromosomes, the structures that carry our genetic information. Of these, two chromosomes determine whether the baby will be male or female: one comes from the mother’s egg, and the other from the father’s sperm.

• The egg always carries an X chromosome
• The sperm can carry either an X or a Y chromosome

If the sperm that fertilises the egg carries an X chromosome, the baby will be a girl (XX). If the sperm carries a Y chromosome, the baby will be a boy (XY).

This means that a baby’s sex is set in stone from the very beginning, long before the first antenatal appointments or ultrasound scans.

Five persistent gender prediction myths – and the truth behind them

Despite the science, many people still turn to age-old myths when trying to guess their baby’s sex, especially in the early weeks before scans or tests are possible.

While these theories can be fun to explore, it’s important not to take them too seriously.

Here are 5 of the most common gender prediction myths still shared today, and what science really says about them.

1. The Ring Test

For this tradition, the pregnant woman lies on her back while someone dangles a wedding ring over her bump on a piece of string.

If the ring swings in a circle, it’s a girl according to the myth. If it swings back and forth, it’s a boy.

In reality this test has no scientific basis, and its accuracy is about the same as flipping a coin. It’s certainly not a reliable method for choosing names or planning your nursery décor!

2. Watering the plants

One of the earliest recorded examples of a baby gender test comes from Ancient Egypt.

The woman would urinate on barley and wheat seeds. If the seeds sprouted, it confirmed pregnancy. Barley growth meant the baby was a girl. Wheat growth meant a boy.

Incredibly, a 1963 study found this method could detect pregnancy with around 70% accuracy, likely due to oestrogen in the urine promoting seed growth. However, it had no value whatsoever in revealing the baby’s sex.

3. Sugar and spice

Some people still believe that pregnancy cravings hold the key to a baby’s sex.

Craving sweet foods? You’re having a girl. Prefer salty or spicy snacks? It’s a boy.

In reality, cravings are more likely to be linked to hormonal changes or nutrient deficiencies than the baby’s sex. There’s no evidence to suggest the expectant mothers’ snack choices offer any clues about whether the baby is a boy or a girl.

4. Bump shape

It’s often said that the way a woman carries her baby can reveal the sex. A high bump supposedly signals a boy. A low bump points to a girl.

But bump shape and position are influenced by many other factors, including:

• The mother’s body shape and core strength
• The baby’s size and position
• Whether this is a first pregnancy

As pregnancy progresses the bump often drops naturally, especially close to birth. So, this myth doesn’t hold up to scrutiny.

5. Baby’s heartbeat

This myth dates to the Victorian era when doctors began listening to foetal heartbeats. A heart rate under 140 beats per minute (bpm) was said to indicate a boy. A faster heartbeat meant a girl.

Modern medicine tells us that a healthy heart rate can vary throughout pregnancy, regardless of the baby’s sex. The key thing is that the rhythm is steady and within a healthy range.

The only accurate way to determine a baby’s sex before birth

While some parents enjoy guessing their baby’s sex using old wives’ tales or instinct, expectant parents looking for a reliable answer usually turn to medical science for answers.

Why ultrasound scans aren’t always conclusive

The first ultrasound scan is usually performed around 20 weeks into pregnancy and can sometimes reveal the baby’s sex, but it’s not always definitive.

The clarity of the scan depends on several factors including the baby’s position in the womb, and the experience of the sonographer performing the scan.

If the baby isn’t in the right position or the genitals aren’t clearly visible, the result can be inconclusive or even incorrect.

DNA testing: a scientific approach

Thanks to advancements in genetic testing, it’s now possible to determine a baby’s sex with accuracy much earlier in pregnancy, and without needing to rely on ultrasound images.

Here’s how a baby gender test works:

• From as early as 6 weeks into pregnancy, small amounts of the baby’s DNA circulate in the mother’s bloodstream
• By analysing this blood sample in a laboratory, scientists can look for the presence of a Y chromosome
• If a Y chromosome is detected, the baby is a boy
• If no Y chromosome is present, the baby is a girl

AlphaBiolabs is also the only laboratory to offer the TinyTAP collection device for blood sample collection, allowing you to collect your own sample at home, quickly, easily, and painlessly!

This convenient, fuss-free method also means you can collect your sample with no need for clinical appointments or additional collection fees.

If you would prefer to have your blood sample collected by one of our clinicians, you also have the option to order a Clinical Baby Gender Test.

Ready to find out the sex of your baby?

Simply order your test online now and choose your preferred method of sample collection at checkout:

• An appointment at one of our walk-in centres (included in the cost of your test)
• Self-collect at home with TinyTAP*
• An appointment at an address of your choice*

If you require a sample collection appointment, a member of our team will contact you to book your appointment.

You’ll receive your results in 3-4 business days after your blood sample arrives at our laboratory.

For more information about our Baby Gender Test, visit our Learning Centre or contact us on 01 402 9466 / info@alphabiolabs.ie.

*Additional fees apply