If you are pregnant, you may want to find out your baby's gender. This is one of the biggest curiosities of pregnancy and also one of the most exciting. Are you growing a son or a daughter in your belly? Many women want to know their baby's gender before the ultrasound confirms it; this way, they can start preparing the room, choosing names, buying clothes, or simply imagining what it will be like.

However, there are also families who prefer to keep the mystery until birth. Not everyone wants to know the baby's gender; for some parents, learning it at the moment of birth is a unique and exciting experience, and during this time, they focus only on having a healthy pregnancy.

For those who want to learn more about this, we will explain in detail on MadresHoy how to find out the baby's gender: from truly reliable medical methods to methods you can apply at home and the most popular myths. This way, you will be able to distinguish what is science, what is play, and how accurate each option can be.

Method of Learning the Baby's Gender with Ultrasound

Ultrasound or ultrasound tests are the most common and accessible method to learn the baby's gender. In addition to checking whether everything is developing properly, it also allows visualization of fetal genital organs.

In most pregnancies, the gender can be seen between the 16th and 21st weeks of pregnancy; the second trimester ultrasound (commonly referred to as morphology ultrasound) is the most common time to report this. In this examination, the specialist checks the baby's anatomy in detail and, if the position is suitable, determines with quite a high degree of accuracy whether the baby is a boy or a girl.

In many countries, including Spain, this ultrasound is included in public health services. If you want to have an additional ultrasound, to get ahead of time, or to see the baby in 3D/4D, you can consult a private clinic, but these services usually come with a cost. Even with modern equipment, it may not always be possible to see the gender: If the baby is facing backward, has crossed legs, or is not in a suitable position, the image will not be clear, and the specialist may prefer to wait.

Additionally, the ultrasound has a high reliability (around 95-99% in clear images), but there is also a small margin of error. Therefore, many specialists act cautiously if the image is not clear and prefer to provide information only when they see it definitively.

Genetic Tests and Blood Analyses to Learn the Baby's Gender

Aside from ultrasound, there are also genetic tests and blood analyses that allow you to learn the baby's gender with high accuracy. It is important to distinguish between invasive and non-invasive tests.

Invasive Tests: Amniocentesis and Chorionic Biopsy

Invasive tests are primarily used to diagnose chromosomal or genetic abnormalities, not to learn the gender. However, this information is also obtained when analyzing fetal DNA.

  • Chorionic villus sampling (chorionic biopsy): usually performed between the 10th and 13th weeks of pregnancy. A small tissue sample is taken from the placenta. It allows you to learn the baby's gender with nearly 99% accuracy.
  • Amniocentesis: usually performed between the 15th and 20th weeks, but sometimes it can be done a little earlier if the medical team deems it appropriate. A sample is taken from the amniotic fluid surrounding the baby. It also offers very high reliability for learning the gender.

Both tests carry a small risk of infection or pregnancy loss. Therefore, they are not recommended solely for learning the gender; they are performed for specific medical reasons (risk of genetic disorders, family history, findings from other tests, etc.). When conducted, the gender is reported as additional information.

Non-Invasive Prenatal Tests and Maternal Blood Analyses

In recent years, non-invasive prenatal tests (NIPT) and other specialized analyses based on maternal blood have become popular. These tests allow for learning the baby's gender from a sample of the mother's blood.

Fetal DNA fragments circulate in the mother's blood. By analyzing this sample in a laboratory setting, the presence of the Y chromosome is investigated:

  • If the Y chromosome is detected, the baby is male.
  • If the Y chromosome is not detected, the baby is female.

These tests can be performed from the 8th to 9th week of pregnancy depending on their techniques and pose no risk to the mother or fetus; because they only require a blood analysis. The accuracy in determining the gender is very high, provided that the fetal fraction (the amount of baby-related DNA in the mother's blood) is sufficient.

Additionally, these non-invasive analyses can predict the risk of common genetic disorders by examining certain chromosomes. They do not replace invasive tests when a definitive diagnosis is needed, but they provide a lot of information, including gender, without risking the pregnancy.

Belly Size and Shape: Myth or Reality?

You have probably heard many times that the shape of the belly indicates whether a boy or a girl is expected. Old tales say that if the belly is round, it means a girl, and if the belly is sharper and protruding, like a “cucumber,” it means a boy.

Other myths add that if the belly is higher and round, a girl will be born, and if it looks “lower” and longer, a boy will be born. Such beliefs are common in various countries and cultures.

However, from a medical perspective, there is no relationship between the shape of the belly and the gender of the baby. The silhouette of the belly depends on many factors:

  • The mother's physical structure and the shape of her uterus.
  • The number of previous pregnancies (the uterus of a first pregnancy is not the same as that of a woman who has had previous pregnancies).
  • Weight gain and the distribution of body fat.
  • Fluid retention and the tone of the abdominal muscles.
  • The position of the baby at any moment within the uterus.

For all these reasons, while it may be fun for the family to guess “is that belly a boy or a girl,” the likelihood of being correct is 50%, just like flipping a coin.

Chinese Chart and Mayan Chart

The Chinese Chart in Pregnancy has become quite popular on the internet for predicting the baby's gender. According to tradition, you only need to combine two pieces of data:

  • Mother's age and
  • The month of the baby's birth.

By placing both in the chart, you can learn the baby's gender. Some people claim that if the chart is incorrect, it is due to the Chinese counting age differently (they have an age when born) and suggest that mothers add a year to their age.

There is also a Mayan Chart; this chart works similarly: the mother's age is combined with the month of birth, and the color of the box (usually blue or pink) indicates the gender. These methods are widely used on social media, forums, and in groups of pregnant women.

Despite being famous, they have no scientific basis. Studies comparing the results of these tables with actual baby gender have found that the accuracy rates are very close to 50%; which is akin to a completely random guess. Therefore, they can be used as a game, but should not be used as a reliable method for decision-making.

Fetal Heart Rate

Many years ago, the idea emerged that fetal heart rate could predict the baby's gender: if the heart rate is above 140 beats per minute, it was said to be a girl, and if below, a boy.

This belief became so popular that many pregnant women ask whether this value gives a clue about gender when they hear the heartbeat during ultrasound. However, research has shown that this relationship does not exist. The baby's heart rate:

  • Is very variable throughout pregnancy and can even change during the same examination.
  • Depends on factors such as the baby's current activity or the mother's condition.
  • Is used to assess fetal health, not to determine gender.

Some studies have attempted to test the validity of this rule, but the results again found a 50% chance of accuracy. Nevertheless, many families continue to “guess” the gender by listening to the heartbeat; this can be fun, but it is important to remember that it is not a reliable criterion.

Ramzi Early Ultrasound Method

This technique, known as the Ramzi Method, is recognized for determining the baby's gender from the 6th week of pregnancy with an early ultrasound. The aim is to observe the position of the placenta within the uterus:

  • If the placenta is located on the right, it is assumed to be a boy.
  • If observed on the left, it is assumed to be a girl.

This method generates great curiosity as it offers the opportunity to “play” with the first ultrasound, but it is important to be aware of its limitations:

  • Ultrasound images can be shown in different orientations (like reversed or mirrored); therefore, everything that appears on the right side of the screen may not correspond to the anatomical right side of the mother.
  • So far, independent studies have not found solid evidence to support the accuracy of the method.
  • It is not part of official diagnostic protocols, and many experts view it as a myth.

In short, analyzing the position of the placenta in the initial images can be fun, but nowadays we do not recommend using the Ramzi method as a reliable gender determination method. It is better to wait for the second trimester ultrasound or genetic tests for accurate information.

Mobile Applications and Online Tests

In the digital age, mobile applications and online surveys have emerged, promising to predict the baby's gender. Some applications combine ovulation tracking functions with gender calculation; these calculations are based on theories such as due date, mother's age, cycle length, or the Chinese calendar.

Most of these applications are based on the myths and traditional tables we mentioned, but they offer a more modern and interactive format. There are even some “quiz” style tests; in these tests, questions are asked about appetite, nausea, belly shape, or changes in appearance, and they ultimately tell whether it is “a boy or a girl.”

While they can be fun while waiting for the ultrasound during pregnancy, their actual reliability is low. In practice, the accuracy rate is again around 50%. The interesting aspect of these tools is that they help share the excitement with a partner, friends, or other family members, but they should not change medical recommendations or affect objective preparations for the baby's arrival.

The positive side is that in the middle of pregnancy, when the ultrasound reveals the gender, you can check whether the application or test was correct and view it as a game of this stage.

Methods and Popular Beliefs for Discovering the Baby's Gender at Home

In addition to charts and the shape of the belly, many cultures have passed down methods used at home to predict the baby's gender from generation to generation. None of them have scientific support, but they are harmless, and many pregnant women practice them as a game.

Changes in the Mother's Body

Some beliefs focus on the physical appearance or how the pregnant woman feels:

  • The mother's beauty: if the skin is brighter, hair is shiny, and the pregnant woman appears “more beautiful,” it is said that a boy is expected. Otherwise, if the face looks paler, acne or spots appear, and the hair looks drier, a girl is expected; because “girls take the mother's beauty.”
  • Face shape: if the face looks rounder, it usually means a girl; if it looks sharper, it is assumed to be a boy.
  • Body hair: if body hair grows faster or the hair looks particularly strong and silky, some legends associate this with a boy; if it does not change much, it is associated with a girl.
  • Cold feet: feeling very cold feet during pregnancy is associated with expecting a boy in some places.
  • Fatigue and sleep: excessive sleep or extreme fatigue is associated with a gender; however, the popular versions vary by region.

Typical Discomforts: Nausea and Headache

Nausea in the first trimester has also been used as a clue:

  • If there is lots of morning sickness, it means a girl is expected.
  • If there is very little nausea or the beginning of pregnancy is “easier,” it is associated with a boy.

Some beliefs regarding headaches assert:

  • If the pregnant woman experiences frequent headaches, it means she is expecting a boy.
  • If there are no headaches or very few, it indicates a girl.

The truth is that both nausea and headaches are related to hormonal responses and each woman's individual sensitivity, not the baby's gender. Studies have been conducted trying to associate specific symptoms with a gender, but the results do not allow for a direct relationship.

Food Cravings

Cravings during pregnancy are also part of these games. According to traditions:

  • If there is a particular desire for sweets, chocolate, very sweet fruits, or pastries, it means you are expecting a girl.
  • If salty or sour foods, pickles, salty cheeses, or deli products (always among those allowed during pregnancy) are preferred, it is associated with a boy.

In fact, cravings are more related to hormonal changes, nutritional needs, and emotional states, not the baby's gender. Still, it can be quite fun to keep a list of what cravings occur and what “results” are indicated.

Ring or Swing Test

One of the most famous home tests is the ring test:

  • A ring (usually an engagement ring) is tied to a string or chain, creating a small swing.
  • The pregnant woman lies down, and another person holds the swing over her belly or palm.
  • If the ring moves side to side, it means a boy is expected.
  • If the movement is circular, it means a girl is expected.

There is no physical basis showing the relationship of these movements to the baby's gender; the movement usually occurs due to the unconscious influence of the person holding the string. However, this is one of the classics of fun tests during pregnancy.

Oil, Baking Soda, and Other “Experiments” Test

There are also other very popular home laboratory tests:

  • Oil test: the pregnant woman lies down and someone drops a few drops of oil (for example, olive oil) on her belly. If the drops remain almost still or move very slowly, it means there will be a girl; if they slide quickly, it means there will be a boy.
  • Baking soda test: the first urine of the morning is collected in a cup, and an equal amount of baking soda is placed in another cup. It is mixed and observed: if the mixture bubbles a lot, it means there will be a boy; if nothing happens, it means there will be a girl.
  • Cabbage test: purple cabbage is boiled, the cooking water is kept, and after it cools down, it is mixed with an equal amount of the pregnant woman's urine. If the liquid turns pink or red, many traditions say it indicates a boy; if it becomes more purple, it means there will be a girl.

All these tests are harmless when done with cleanliness and common sense, but none are supported by scientific studies. The chemistry of urine (pH, concentration, etc.) is influenced by the mother's nutrition, hydration, and metabolism, not by the baby's gender.

Emotional State and Decision to Know the Gender

Beyond the methods of learning the baby's gender, another important point to consider is: how each family experiences the decision to learn the baby's gender.

Some couples feel that learning it early helps them establish a more concrete bond (naming, imagining the face, preparing the room or clothes). Others prefer to keep the surprise until the end for different reasons:

  • Superstitions or difficult past experiences: after pregnancy losses or other issues, some parents prefer to protect themselves from getting too excited about a specific gender or making detailed plans.
  • Desire to experience pregnancy with fewer expectations: some families think it is better to focus on the baby's health and enjoy each stage rather than focusing on whether it will be a boy or a girl.
  • Fear of mistakes in predictions: although ultrasounds are quite reliable, there can be uncertainties, especially if the image is unclear. Some parents prefer to avoid creating expectations about a gender and then finding out the opposite.

Each of these options is valid. The most important thing is that you and your partner feel comfortable with your decision, without external pressures. Whether you want to know the gender as soon as possible or prefer to discover it at birth, the pregnancy will still be just as special.

In conclusion, there are many myths and home methods to learn the baby's gender, but the only truly reliable ways are medical tests: second-trimester ultrasound, maternal blood analysis (NIPT), and genetic tests if necessary. Everything else can be a lovely entertainment during the waiting period, as long as it is treated as a game and not seen as an absolute truth.