Baby gender myths

We’ve all heard the stories; if a baby carries low it’s a boy, or if you cop bad morning sickness it’s a girl. But do these old wives tales ring true?

Bupa's National Medical Director and GP Dr Tim Ross explains which are myths or medically reliable.

Predicting the sex of your baby can be a lot of fun, it’s one of life’s great surprises and everyone has a theory. 

But Dr Ross cautions against painting your nursery or buying all of bub’s clothes based on one of the following myths.

Gender myths

It’s a boy if…

  • Your baby carries low 
  • You eat more during pregnancy
  • You crave sweet things
  • The dad puts on weight during the pregnancy
  • Your pillow faces north when you sleep 
  • Your urine is bright yellow in colour 
  • You get headaches
It’s a girl if…

  • Your morning sickness lasts all day 
  • You crave sour foods 
  • Your face is round during pregnancy
  • You get acne when pregnant
  • Your left breast is larger than your right 
  • You are moodier than usual during pregnancy
  • Your hair develops red highlights
“There are all sorts of reasons and justifications behind some of these but there is no scientific evidence behind any of these ideas,” says Dr Ross.

Some weird and wonderful tests

While these tests and calculations can make great baby shower banter or might be a bit of fun with your partner, Ross says the truth in these is as reliable as a random guess.
The Chinese Lunar Calendar 
Add your age (at the time of conception) to the number for the month you conceived. If it is odd it’s a girl. If it’s even it’s a boy.

The ring test
An age old test is to loop a piece of string, or your hair around your wedding band and have someone dangle it over your pregnant stomach. If it moves back and forth, it’s a boy. If it circles, it’s a girl. 

The bicarbonate soda test
Add a teaspoon or two of bicarbonate soda into a glass then add some of your urine. If the mixture starts to bubble, it’s a boy. If there’s no reaction at all, it’s a girl.

The verdict:
“It’s good to have fun with these, have a guess and have a punt, but at the end of the day it’s 50/50,” says Dr Ross.

“A lot of the stuff like the peeing on the bicarbonate soda, that’s probably attributed to the changing level of hormone,” he says. “The mother’s hormonal changes will completely overwhelm any hormonal influence from the tiny little foetus sitting in the uterus, so it’s not going to influence any test such as that.”
pregnant woman holding picture

The medically reliable

If you really want to know whether you’re having a girl or a boy, there are plenty of medically reliable baby gender tests out there. 

The 20 week ultrasound
One of the most common ways people find out the sex of their baby is at an ultrasound. Ross says at the 20 week scan, you get a pretty accurate determination of your baby’s gender. As the test is primarily a medical examination, it’s not always possible if your baby is in an awkward position with his or her legs crossed. It can even show at the 12 week ultrasound but there is a fair amount of guesswork involved and it also depends on the baby’s position.
Non-invasive prenatal testing (NIPT)
NIPT is a blood test taken from your arm which examines pieces of the baby’s DNA found circulating in mum’s blood. The primary purpose of the test is to screen for common chromosome conditions in newborns including Down syndrome, Edwards syndrome and Patau syndrome, but it can also determine your baby’s sex with an accuracy rate of about 99.5%.
This test can be taken from about 10 weeks. It’s not covered by Medicare and costs around $500.
An amniocentesis is an invasive test which screens for chromosomal abnormalities like Down syndrome. It’s also the most accurate way to determine a baby’s sex. 
A person may choose to have an amniocentesis if their combined first trimester screen revealed they have a high risk of birth defects. The test involves a needle, guided by an ultrasound, being inserted through the abdomen and into the uterus, to take a sample of amniotic fluid. The test involves a small (1 in 200) chance of causing a miscarriage.
Chorionic Villus Sampling (CVS)
Again, this is a test normally performed if someone has an increased risk of genetic abnormalities, but can also accurately reveal a baby’s gender. 
It involves taking a small sample of the developing placenta, using a small needle inserted through your abdomen. The sample is then examined in a laboratory. There is a one per cent chance this test can cause a miscarriage.
Finding out whether you’re having a baby boy of a girl, either while pregnant or after delivery is such a special moment in your life. Don’t forget to let your doctor and/or sonographer know whether you’d like to find out early or not to make sure the big news is revealed at just the right time.

You can find information, support and inspiration to help guide you through the first thousand days your parenting journey, from conception to two years old, here.

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