A thick line indicates a male and a thin line represents a female. If any line cuts by bar line then always chances of abortion or miscarriage.
Yav and barley sign on the base of thumb also indicates children. Big yav denotes male child and small yav shape denotes female child and if yav is cut by any line then it denotes abortion or miscarriage.
If children line forked like a "V" indicates twins. See - 1
Islands in the base of the thumb also indicate number of children. If there are two islands attached to each other like "8" indicates twins. See - 2