How to choose the sex of the baby: Traditional and scientific methods

First of all, if you want to have a boy, congratulations! Of every 100 births in the world, 51 are male and 49 are female, so statistically following the natural method of conception, you are slightly more likely to have a child. Now, to tip the balance, one of the most popular methods is that of Shettles.

Shettle’s method

This method is based on a genetic difference between male and female spermatozoa, the “Y” chromosome of men is smaller than the “X” chromosome of women, this produces that male spermatozoa are smaller and faster, but female spermatozoa are smaller and faster. although slower, they can be more resistant and survive longer in the womb.

We invite you to use our ovulation calculator since the theory says that if you want a man, the ideal is to have intercourse several times on the day of ovulation and the days after, so the male sperm have a better chance of arriving first and if you want a girl you have to have intercourse only once 3 or 4 days before ovulation so that the female sperm are more likely to be the only ones to survive.

Shettles plus penetration, feed or chemicals

Some variations of this method include using low-penetration sexual positions if you want to have a girl, since only the strongest spermatozoa should reach the egg, as well as eating foods that can alter the acidity levels in the vagina: Acidic foods if you you want a girl and more neutral if you want a boy.

In the most extreme cases, there are those who introduce gels or chemicals to alter the pH of the vagina, but this can cause infections or serious fertility complications. Defenders of the Shettles method claim that it has a 75% success rate, however, there are two fundamental problems with this method.

The problem with Shettles

The first is that the difference in size is not as extreme as is usually drawn in the diagrams, in reality the difference is a maximum of 3% in the volume of the head and this does not affect the size or shape of the body and tail, and as As we have seen in previous videos, many sperm have slight deformations, so there may be larger and more resistant male sperm than female sperm and there may be female sperm much faster than the rest.

The second problem is even more serious, because even if a female sperm can survive for 4 days, this does not guarantee that the genetic material remains intact, so if fertilization occurs, the embryo could have various problems in its development.

Ericsson method

In some fertility clinics, the Ericsson method is offered, which follows a similar principle: The semen sample is centrifuged and in theory the largest and heaviest female sperm will remain at the bottom of the sample, so if a boy is desired, a artificial insemination or in vitro fertilization collecting sperm from the upper part and if a girl is desired, sperm from the lower part will be used.

Proponents of this technique claim that it is 75% successful, but again… The actual difference between male and female sperm is only 3% so there are many flaws in the method.

Genetic Diagnosis

When analyzed objectively, one of the main reasons why a couple decides to choose sex is to rule out hereditary diseases. Diseases such as color blindness, hemophilia, aneurysms, and even autism are predominantly male, while Sjögren’s syndrome, scleroderma, osteoporosis, and Alzheimer’s tend to affect women more, so if you want to avoid a hereditary disease, most People want to be 100% certain.

That is why at Creafam we carry out a preimplantation genetic diagnosis, which basically means that once the embryos are fertilized we can analyze their chromosomes and thus know the sex, but we can also know if an embryo is likely to develop Down syndrome or other genetic diseases, thus providing the maximum certainty and security about the health of the baby. If you are already looking for a pregnancy, remember to attend a preconception consultation to resolve your doubts and prepare yourself to fully enjoy your fulfilled dream.