Maiesiophilia (or Maieusiophilia) is the sexual fetish for pregnant women and/or childbirth. See Pregnancy fetishism.

On occasion the fetish is not contained to humans, as some childbirth fetishists are similarly aroused by images of animals giving birth. It is said that a potential cause of maiesiophilia is the lack of a mother figure in the fetishist's life, thus making him/her lustful for someone who will be a mother. However, this theory is subjective and mostly considered a misconception by the Maiesiophiliac community, the majority of whom have mothers.

The arousal caused by Maeiusiophilia could possibly be attributed to the following reasons:

While the woman is pregnant, men can ejaculate inside them without the problem of the woman conceiving since she has already conceived.
Pregnant women can get more aroused than normal, so men/women have more sex than usual.
A pregnant woman can be viewed as the height of feminism and eroticism.
The big belly. This is the most common cause of arousal.
However, many self-confessed Maeiusiophiliacs would say that they do not believe this, and that in most cases their preference is inexplicable, essentially instinctual.