Can the astronauts have children on Mars?

Mars One will advise the first settlement inhabitants not to attempt to have children because:

In the first years, the Mars settlement is not a suitable place for children to live. The medical facilities will be limited and the group is too small.
The human ability to conceive in reduced gravity is not known, neither is there enough research on whether a fetus can grow normally under these circumstances.

In order to establish a true settlement on Mars, Mars One recognises having children is vital. Therefore this will be an important point of research.