Since the probability of having a girl is determined by the male’s sperm, there is usually no way to increase the probability of having a girl in case of natural conception. The sex of the baby cannot be controlled because it is determined by the father’s chromosomes. If the father’s X chromosome-containing sperm fertilizes the baby, then the baby is a girl. However, if the father’s sperm containing Y chromosome is fertilized, the baby will be a boy. In fact, for both men and women during the preparation period, whether it is a boy or a girl baby, it is their own baby. It is recommended that during the preparation for pregnancy, both husband and wife should change their dietary habits, eat more grains and cereals, chicken, duck, fish and meat to supplement the nutrients, quit smoking and drinking, and exercise properly.