When the ultrasound reveals a hypotonic gestational sac, it is advisable to treat the pregnancy with fertility preservation and to review the ultrasound regularly to observe the growth and development of the embryo. A hypotonic gestational sac indicates an irregular shape of the gestational sac on ultrasound, indicating a possible abnormality in the development of the embryo. Therefore, when there is poor development of the gestational sac, it is recommended to apply appropriate birth control medication and to improve the blood progesterone and chorionic gonadotropin tests to assess the development of the embryo, as well as to review the ultrasound regularly to dynamically compare the growth and development of the gestational sac.