Why would a man reject a woman he claimed to love when she becomes pregnant for him?
This is one of those questions that do not have one straight answer because it could be because of many different reasons depending on the individual who has done it.
Most men who do this because of various reasons like, not being ready for a child or even the relationship itself, running away from responsibility, they could be running away from the commitment to the girl. It could be because they fear their family reactions and others are just irresponsible and don't care about the child or its mother.
It could be a lot of other reasons as well. The important thing is to always try to know your partner well before you take a risk like having unprotected sex. Better still is to consider use of contraceptives like condoms and others not to just prevent infections but also unintended pregnancy.
Learn more about contraceptives here https://lovematters.co.ke/resource/birth-control-methods .