Boy or Girl: When and How Can You Find Out Your Baby's Sex?

The positive test has barely been put away when the question comes, at the family dinner table as at work: "So, boy or girl?" Some mums-to-be want to know as early as possible, others prefer to keep the surprise until the birth. Either way, it helps to know what is reliable, and what is just a game.

Here is when your baby's sex becomes visible, what blood tests can tell you, what to make of old wives' tales, and a few ideas for announcing it.

When is the baby's sex decided?

At fertilisation. It depends on the sperm that fertilises the egg, which carries either an X or a Y chromosome. But the genitals take several weeks to form and differentiate: according to the Mayo Clinic, the external genitals start to develop around 11 weeks. Before that, no imaging test can tell a girl from a boy.

At which scan can you see the sex?

The sex often becomes identifiable on a scan around 14 weeks, according to the Mayo Clinic. At that stage it is still tricky to see, and most parents find out at the second-trimester scan, around 20-22 weeks, as the Larousse encyclopaedia points out. The medical website Altibbi also considers it the most reliable time.

Your baby still has to cooperate: depending on their position, the sonographer may not be able to say. The Quebec guide Mieux vivre avec notre enfant stresses that the sex can often be revealed, but not always, and with a small risk of error.

Remember that the second-trimester scan is first and foremost a medical examination: checking your baby's organs one by one. Everything it looks at is explained in our article on pregnancy scans.

The blood test (fetal DNA): reliable, but not designed for this

During pregnancy, small fragments of the baby's DNA circulate in the mother's blood. Analysing this fetal DNA (often called NIPT) screens for certain chromosomal conditions, such as Down syndrome (trisomy 21) or trisomy 18, and can also show the sex, the Mayo Clinic explains.

This test is above all a medical screening test, with specific indications. In Quebec, it is offered as a second step, when the first screening shows a higher chance of trisomy, or straight away in certain situations: mother aged over 40 at the birth, a previous pregnancy with trisomy, multiple pregnancy. Like all screening tests, it isn't perfect. Talk to your gynaecologist, who will tell you whether it is useful in your case and what it costs.

Chinese calendar, pointed bump, cravings: are old wives' tales worth anything?

They are part of pregnancy folklore, in Morocco as elsewhere, and there is no reason not to enjoy the game. But none of them has any predictive value.

Remember the simple rule: any method that "guesses" between two possibilities has about a one-in-two chance of being right, even knowing nothing at all. That is why every family has a method that has "never been wrong".

Announcing the sex: simple, safe ideas

Once you know the sex, nothing obliges you to shout it from the rooftops. Some couples keep it to themselves, others organise a small reveal. A few easy ideas:

• a cake with a pink or blue inside, revealed with the first slice;
• a box full of balloons to open in front of the family;
• a little bodysuit or booties slipped into an envelope for the grandparents-to-be;
• a video call for family living far away, in Paris, Madrid, Montreal or elsewhere;
• the reveal as part of a party you were already planning, such as a baby shower.

Keep the party simple: no fireworks or smoke bombs near a pregnant woman, and nothing staged that stresses you out. And if you haven't yet announced the pregnancy itself, our article on announcing your pregnancy has ideas for the dad-to-be, the family and work.

Baby clothes: pink, blue or neutral?

Until the sex is confirmed, go for basics in neutral colours, white, beige or grey, such as cotton bodysuits and vests: they suit every baby and can be used again for a future child. To put together the rest of the newborn wardrobe, size by size, follow our guide to the newborn layette (in French). If you are putting together a baby registry, your loved ones can choose from it.

From the shop

Baby clothes that suit every baby

While you wait to find out, or to keep the surprise: white or beige basics and a pretty going-home outfit, at a range of prices.

• −74 %BabiduLong-sleeved bamboo baby bodysuit, white – Babidu34 DHinstead of 130 DHView product
• −74 %BabiduLong-sleeved baby bodysuit, 6 months, white – Babidu34 DHinstead of 130 DHView product
• −74 %Pureté du bébé3-piece cotton set, 3M, beige 02 220 – Pureté du bébé153 DHinstead of 590 DHView product
• −74 %Pureté du bébéEssentials velvet sleepsuit, girl, 1 month, beige, model 216 – Pureté du bébé164 DHinstead of 630 DHView product
• −74 %Pureté du bébéEssentials velvet sleepsuit, 3 months, white – Pureté du bébé203 DHinstead of 780 DHView product
• Mac IlusionTenderness 3-piece christening outfit, white, size 3 months – Mac Ilusion500 DHView product
• The whole aisle · Christening and coming-home outfits16 products online, delivered anywhere in Morocco.Open the aisle

Products sold by La Maison du Bébé, publisher of this magazine. Prices as of 12 October 2026; please check the product page.

And once you know the sex, it is time for another big family discussion: the name. Our lists of Arabic boys' names and Arabic girls' names, with their meanings, are there to inspire you.