Sexe de bébé : décrypter la première échographie grâce au bourgeon génital - Élhée

Sex of baby: deciphering the first ultrasound using the genital bud

According to a study carried out by INED ( National Institute of Demographic Studies), 9 out of 10 couples want to know the sex of their unborn baby, in particular to choose their first name and better prepare for their arrival. Speaking of which, have you ever heard of the genital bud? A name evocative of a whole concept around birth, growth... and the sex of the child. Yes, today we are going to talk about the first prenatal ultrasound, the one from which the predictions are made! So, girl or boy? It all starts with a bud.


The first trimester ultrasound, THE long-awaited moment

Scheduled around 12 weeks of pregnancy, the first trimester ultrasound, also called dating ultrasound, is often the first meeting with your baby . While your belly is just starting to round out, while you may not have even told those around you the good news yet, parenthood is becoming a tangible reality. For the first time you see him move. For the first time, you hear his heartbeat. And for the umpteenth time, you ask yourself:

  • “Is it a girl or a boy?” »

But, beyond this crucial question, the first ultrasound serves above all to reassure you that your pregnancy is going well . Using medical imaging, the sonographer checks the presence of the gestational sac in the uterus, and that of the embryo. Without an embryo, we speak of a clear egg, without cardiac activity of the fetus, of an arrested pregnancy and if there are several fetuses, of a twin pregnancy. All of this information is checked one by one to ensure the viability of your pregnancy.

This is also when you get a precise date of start of pregnancy, and therefore an expected date of delivery (DPA)!

Your doctor or midwife will then take a detailed look at your baby, measuring the cranio-caudal length (from head to seat) among others. Nuchal translucency is also assessed to estimate the risks of Down syndrome. If the fetuses have a slight separation between the skin of the neck and the spine, a space greater than the norm suggests an increased risk of Down syndrome. Risk which also increases with the age of the mother and depending on the heredity factor.

Finally, if you wish to know the sex of your child and only at your request, it is possible that your midwife or your doctor will discuss his genital bud with you.

The genital bud: what is it?

To give a definition of the genital bud, or genital tubercle, let's say that it is an outline of a penis in the baby boy or an outline of the clitoris in the baby girl .

baby first trimester ultrasound

Determined as soon as the egg is fertilized by the sperm — two X chromosomes give a girl, one SG) or 7th week of amenorrhea (SA). You then have to wait around 9 weeks to see a real difference appear between girls and boys.

At 12 weeks, at the time of your first ultrasound , if you are expecting a boy, his penis is taking shape while his testicles are already secreting testosterone. If you are expecting a baby girl, the uterovaginal canal, ovaries and fallopian tubes develop in her body.

It is this difference, in the form of a tubercle, which allows a trained eye to make its first predictions.

The genital bud method to guess the sex of the baby

  1. Use a clear image of your baby taken whole and horizontally at the time of the first ultrasound.
  2. Locate the genital bud located at the bottom of the abdomen, between the legs, and the spine.
  3. Compare the location of the bud in relation to the column, especially its inclination . If they are more parallel to each other, you are probably expecting a girl. If the bud is pointing upwards, it's probably a boy.

However, if the photo is a little blurry, if baby turns his back to you or if his hand moves when the photo is taken, that's the end of the guesswork! You will have to wait until the second trimester morphological ultrasound to find out more.

Before 22 SA, an uncertain interpretation

In optimal conditions, if the fetus is the right way up and the image quality is good, interpreting the genital bud is a fairly reliable (but never certain) method of getting a good idea of ​​the sex of the unborn baby.

That said, keep in mind that no technique is infallible . As proof, who has never known a mother ready to welcome a little boy, who ultimately gives birth to a little girl, or vice versa? While the sex of the baby is usually revealed with certainty during the second trimester ultrasound, some mothers only have a definitive answer once their newborn is nestled in their arms.

Morphological ultrasound, a confirmation

The morphological ultrasound is the second obligatory examination of your pregnancy. Carried out during the 5th month, between 21 and 24 weeks , it is longer than the others and focuses in detail on the growth of your baby, who then measures on average 25 cm from head to toe, for 500 grams.

As the main objective of the dating ultrasound is to verify the correct implantation and viability of the fetus, the objective of the morphological ultrasound is to look for possible fetal anomalies.

The practitioner therefore takes cross-sectional images of the different organs , heart, brain, stomach, bladder and intestine, but also of the baby's arms and legs, to check that everything is fine. Finally, your little one is measured from every angle : biparietal and transverse abdominal diameter, cranial and abdominal perimeter and femoral length.

On the mother's side, the different aspects of the placenta are studied, the quantity of amniotic fluid is checked as well as the cervix.

Once all these steps have been completed, your doctor or midwife are generally able to tell you the sex of your baby.

Please note: if you do not want to know the sex of your baby, say so and remind yourself as often as necessary during your prenatal check-ups. Yes, sonographers being used to the impatience of future parents, are likely to share the information with you very quickly!

To reveal the sex of the baby or not?

guess the baby's sex using his mother's pregnant belly

Genital bud, morphological ultrasound, in 3D and sometimes even additional, very impatient you try everything to finally know if a little boy or a little girl will come to enlarge the family.

Other future parents, after having examined the baby's tubercle without success or after a second trimester ultrasound carried out with their backs turned, abandon any idea of ​​discovering the sex of their child before birth to let themselves be carried away by the surprises of life.

Sometimes, reassured by the revelations of the genital tubercle, couples choose to wait until the day of delivery to have confirmation.

Finally, by superstition, by conviction or because they are already parents of children of both sexes, a certain number of future mothers and future fathers choose to keep the whole secret. Whatever happens, know that this intimate decision is yours alone.

And what about grandma’s tips then?

The shape of your pregnancy belly or your food desires would say a lot about the child you are expecting. Indeed, there are many grandmother's tricks to try to unlock nature's greatest secret.

  • Pronounced nausea would be associated with the birth of a girl. And why not ? In October 2020, an American study showed that the birth of a girl leads to higher levels of the hCG hormone. However, its high concentration is responsible for nausea at the start of pregnancy.
  • In terms of eating during pregnancy , wanting to eat sweet foods would be the sign of a baby girl, while preferring savory dishes would mean that you are expecting a boy. Do you validate?
  • The shape of the pregnancy belly would also be a clue to study. Tall and pointy? It's a boy. Low and wider, it's a girl. That said, the shape of your belly also depends on the position of the baby, your body shape and the number of previous pregnancies.
  • Do you know the pendulum test? All you need to do is let a pendulum hang above your stomach and observe its movements. Are they circular? It's a girl. The pendulum swings back and forth? It's a boy.
  • Grandmothers used to say that a baby girl steals her beauty from the mother . Thus, a resplendent future mother would rather be expecting a boy, as opposed to a pregnant woman with pale complexion and tired hair, who would be expecting a little girl .
  • The line that sometimes appears on the stomach of pregnant women, called linea nigra (black line in Latin), would also reveal a little girl's secret, but only if it extends beyond the navel. Otherwise, it's a boy.


Have you tried one or more of these tips? Have you tried to decipher your 12-week ultrasound using the bud method? Tell us if it worked for you!

*Ultrasound source: Medical Imaging of South-East Lyon

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