It is a psychotic pathology. There are people who have children because they....CAN. They maintain that they have the "unmitigated right" to be parents. They are mothers in name only.
There are women who have children because they believe that children are gifts from God. They have children because they are OBLIGATED to do so. They may not want or take care of the children but they feel that they must have children to fulfill some type of preordained obligation. These women make very perfunctory parents at best.
There are women who have children to fulfill voids in their lives whether it is relationship, job, or other psychic voids. Many women have children to fulfill some type of need in their lives. Many of these women have no outside interests so they have....CHILDREN.
There are women who have children to garner attention from others. They use the issue of having children so that people can praise them for being mothers. There are women who somehow feel "glorious" by becoming mothers.
Then there are women who have children mindlessly. They have sex & refuse to use contraception & then become oopsie, pregnant. So instead of using birth control &/or having an abortion, they just have children. They really don't care about their children, they just produce children like amoebic lifeforms.
Then there are women who are theoretically in love w/the idea of motherhood. However, when motherhood actually happens, they are overwhelmed by the responsibility & can't handle it. These women fantasize about the beauty of motherhood but when reality hits, they can't handle motherhood at all.
Then there are women who have children because of a deep-seated psychosis. They have the incessant need to have children(mothers of large families fit this category). However, they don't have to raise the children but oftentimes give the children to oldest/older children to raise & they continue to aimlessly reproduce. Mothers of large/very large families have children yet they don't/won't take care of them as the oldest/older children are THE REAL PARENTS of the family.