Childbirth has been a long time mystery, from conception and fetal development to labor and delivery. Since ancient times, guessing the gender of a developing baby was a sort of divinatory activity mixed with superstitions.

Today, ultrasound makes it possible find to out the gender of the fetus as early as 16 to 20 weeks. However, is not only a matter of guessing a baby's sex, but a useful tool to find developmental problems that can be corrected opportunely, including preventing miscarriages.