Breeding

Breeding is a method of giving birth to a new Pokémon by producing and hatching an Egg.

Conception
Like in the games, it requires two Pokémon to breed a child. However, unlike in the games, they do not need to be of the same Egg Group to conceive. It is quite possible for two Pokémon of different Egg Groups of conceive a child, albeit with some issues. If two Pokémon of different Egg Groups attempt to conceive a child, they will have a harder time and their offspring will most likely be born with some kind of defect (ranging from the infant's appearance to their ability to develop). Because of these risks, it is much preferred for Pokémon of the same Egg Group to breed. Pokémon of the same Egg Group also have a higher chance of multiple births.

After successfully conceiving a child, the Egg will remain in the mother for a period of six months before laying the Egg. The Egg will typically take another three months before hatching if kept healthy. Thus, a healthy delivery will take up to nine months before the child is officially born.

Hatching Eggs
After the Egg is laid, the Egg still requires great care and attention. Eggs must be kept warm and protected from harm. If the Egg becomes too cold or too hot, it could result in danger or even death to the infant dormant inside. However, it has been determined that the temperature the Egg is kept at can determine the gender of the infant. Warmer temperature will increase the chances of the infant being a male while cooler temperature will increase the chances of the infant being born a female. If the Egg receives proper care, it should hatch within three months after being laid. The Egg hatching too soon or taking too long to hatch could be quite dangerous to the infant.

Tips For Caring For Eggs
Upon hatching, the infant will imprint on whomever it sees first, instinctively recognizing them as their parent.
 * Keep Egg warm
 * Protect Egg from any possible harm
 * Wrapping Egg in blankets is highly recommended for protection, warmth and comfort
 * Studies prove that keeping an Egg close to a beating heart will help increase the infant's health and establish a stronger bond with its caretaker(s)

Trivia

 * Breeding Pokémon of different Egg Groups is usually impossible in the games while it is not in the PMD comic series