Thank you for your query and Welcome to HCM community.
Virtually all ovarian Dermoid
Cysts require surgical removal for definitive diagnosis, treatment and staging. So, this cyst must have to be removed, as failure to do this may result in serious life threatening conditions like shock
resulting from haemorrhage and/or torsion of the cyst which is very much painful. Whether ovary will be removed or not , it depends on clinical scenario.
You didn't mention your age. Cysts that occur at second/third decade are usually benign (less harmful), but those occur after 45 usually malignant (ie cancer)
As dermoid cysts occur from the tissue of ovary and it can distort the ovarian structure thereby disturbing the normal function of ovary. So, it can interfere conceiving. After removal of one ovary, if the remaining other ovary is healthy, then there is still chance for conceiving.
Hope, this helps.