This paper is a case report on the success of oocyte retrieval and good quality embryo development following controlled ovarian hyperstimulation at early pregnancy. A 30-year-old patient underwent controlled ovarian hyperstimulation by gonadotropin-releasing hormone agonist long protocol. On the day of oocyte collection, a 5-week gestational sac was observed by exact sonography monitoring. However, via ultrasound guided follicle puncture, 7 oocytes were collected. After intarcytoplasmic sperm injection, 3 developed good quality embryos were cryopreserved. Moreover, the natural pregnancy was continued and finally a healthy live birth was achieved. Despite physiological hormonal changes during pregnancy, the follicular growth occurred and followed by oocyte retrieval and embryo development, subsequently.