A Mother is a type of "job" in Tropico 3 and Tropico 4. When a woman is married to a man, there's a chance each month that she'll become pregnant, changing her sprite to that of a mother.
Tropico 3[]
Motherhood is for a full year. Fire them if they are occupying a productive work slot that is critical. T4 changed their behaviors somewhat. Garages only work for them if receiving funds via work or social security. The contracept ban increases the chances of pregnancy as does the clinic/hospital obstetrics. It has been witnessed that lesbian couples sometimes have a pregnancy; couldn't tell if they were recent relationship changes, so maybe not.
College-educated females have a limit set at the College which is effected by fired mothers with a College education.
Tropico 4[]
She'll continue working at her usual job for a while but will eventually be given maternity leave. After some time, she'll return home and give birth to a toddler before returning to work.
Mothers move very slowly, so it's important to have Garages(Tropico 3 & 4) and metro stations to prevent them from having to walk too far.
The chances of a woman becoming a mother can be increased in several ways, such as by using obstetrics-focused healthcare, banning contraceptives, and starting a Festival of Love.