The endometrium is the innermost layer of the uterus that contains the lining which is responsible for accepting and nourishing a fetus during the pregnancy process. The lining of this cavity changes with every monthly cycle in response to the primary female hormones produced by the ovaries: estrogen and progesterone.
If one parent is more stable than the other, judges can decide to award primary custody to that parent. As a result, parental fitness is often a mechanism used in custody battles. Each state has its own set of rules regarding what makes a parent unfit.
Child custody laws vary by state, but in general, when both parents are alive, the court prefers to place the child with one or both of the parents. Third parties may be able to obtain custody if both parents are unable or unwilling to care for the child. Both parents are deemed unfit.