When sperm fertilizes an egg, the genetic material (DNA) from both parents combines to form a zygote. This is also when the gender of the baby is determined.

The egg always carries an X chromosome, while the sperm can carry either X or Y. If the sperm carries an X chromosome, the child will be female (XX). If it carries a Y chromosome, the child will be male (XY).

Scientific studies show that the acidity (pH) of the female reproductive system also plays a role. A highly acidic environment is unfavorable for Y sperm, increasing the chances of a girl being born. Conversely, an alkaline environment energizes Y sperm, increasing the likelihood of a boy.

After fertilization, the zygote develops its 46 chromosomes in about five hours and travels to the uterus, where it implants and begins developing into an embryo. This entire process takes around seven days, marking the start of a new human life.