The levonorgestrel-releasing intrauterine system is effective and well accepted for long-term therapy after conservative surgery for patients with moderate to severe pain related to endometriosis. It can improve the patient's quality of life, including physical and mental health.

The present study has currently been the largest case series of primary amenorrhea. Müllerian agenesis is the most prevalent cause in our study, while gonadal dysgenesis is the most common cause in the largest-scale study in the USA. Hence, racial, genetic and environmental factors could play roles in the cause of primary amenorrhea.

Our data showed that 17beta-estradiol increased the release of PGI2 from HUVEC via the induction of COX-2 which was mediated through protein kinase C. The results suggested that COX-2 might have a role in the cardiovascular protective effect of estrogen.