Mercury and Saturn both are neuter planets. 5th house belongs to children. That’s why Saturn and Mercury conjunction in the 5th house may cause infertility issues. Native may have problems regarding childbirth.
Mercury is the natural karaka of business and Saturn is the natural karaka of the profession. So, Mercury and Saturn conjunction in 1st house is indicating, that the native may be an expert in business or trading activity. He knows all sorts of tricks to run a business. Such as he can twist any matters for his own profits. He may acquire commercial land.
Native with Mercury & Jupiter conjunction in 10th house is good for earning purpose. He has a good reputation at their workplace. Such natives may have a profession in teaching or banking or the financial sector. He may be getting success in tricky work such as astrology, mathematics, and financial data management.