Humans can live on Mars. The problem comes when reproducing. Apart from being a simple physics problem, Mars is exposed to high radiation levels that could easily damage a fetus or a child. The human ability to conceive in reduced gravity is not known yet. No one has ever researched how a fetus might develop on Mars. A woman still hasn’t given birth on Mars or in a shuttle in space or even traveled to space while pregnant. NASA has not permitted this yet.
The low gravity can cause ectopic pregnancy on women. Ectopic pregnancy is when a fertilized egg attaches somewhere else in your body, usually in your fallopian tube that’s why it’s sometimes called a tubal pregnancy. But they’re very dangerous if not treated. Fallopian tubes can break if stretched too much by the growing pregnancy — this is sometimes called a ruptured ectopic pregnancy. This can cause internal bleeding, infection, and in some cases death. Another option is to genetically modify humans before sending them to space because humans were made to live on Earth, not in other conditions like extreme weather ranges and low gravity.