How To Get Pregnant With History Of Miscarriages?

hiim 32 years i first got pregnant in 2013 but at 28 weeks had to do a c section coz the baby had severe deformarties like the legs and hands did not developed properly then got pregnant in 2014 march but had miscarriage at 7 wks and until now i have not been able to get pregnant again what can i do to get pregnant again and stay pregnant.about the first baby the doctor were unable to tell me why the baby had the deformaties