How long does it take for c-section scars to completely heal? can they re-open?

Few weeks: C-section scars are fairly well healed by two weeks , but it can take up to 4 weeks to be completely pain free. The scars do not reopen , however seromas (collection of fluid) under the skin can leak through small opening in the scar. Occasionally infection can cause the scar to be open in small areas.

Weeks: Scars achieve the majority of their healing potential by 6 weeks from the time of repair of the incision. However, this time could be prolonged if you have health problems which would delay healing. A scar is never as strong as uninjured/normal skin. It is possible for a scar to reopen, but after six weeks this is very unlikely without significant stress to the scar.