Can pocs cause infertility in women. What is the effect on a young woman of 26 year?

Same. Pcos will have the same effects in any woman at any age. Use diet, exercise and weight loss. Talk to your doctor about metformin, which can help normalize menses and may restore fertility in many women.
PCOS. Pcos can cause issues with fertility. You can see your ob-gyn or an endocrinologist who can help you with this. There are medications that decrease Insulin resistance and can help with fertility. Would discuss this with the physician.