Recently, Ms. Liu, who lives abroad, brought her six-month post-operative Niu Niu to the hospital for a review. She was very happy to see that the incision scar was almost invisible if she did not look at the abdomen carefully, and the ultrasound examination showed no obvious abnormalities on the right ovary. However, when she recalled her family’s carelessness, she regretted it. She was very happy when she recalled that her family had been negligent, but she regretted it when she recalled that the prenatal ultrasound examination revealed a cystic mass of about 5.0 cm in diameter in her pelvis in the sixth month of pregnancy, which continued to grow as the gestational weeks increased. When Nui Nui was born at full term, her family was so happy with the birth of her baby that no further treatment was performed. When Niu Niu was 2 months old, she had intermittent crying for several days, and after many local consultations, she could not figure out the cause. Dr. Huang Hua, deputy chief physician of our department, and his assistant Dr. Gu Yachuan, attending physician, performed a single-incision laparoscopic minimally invasive surgery via the umbilicus for the child on an emergency basis. During surgery, bilateral ovarian cysts were found and the left ovarian cyst was twisted and necrotic, so the right ovarian cyst was removed and the left ovary was removed as a last resort. What should be done if ovarian cysts are suspected and found before and after the birth of the baby? Should they be treated surgically? Let’s find the answer step by step from the following aspects. In fact, ovarian cysts are the most common benign pelvic masses in infants and children. Moreover, most infant ovarian cysts are discovered unintentionally during the baby’s prenatal or postnatal ultrasound examination. However, they should be differentiated from other abdominal masses such as mesenteric cysts, intestinal cysts (intestinal duplication malformations), and ovarian cystic teratomas. With the continuous improvement of ultrasound technology, the initial diagnosis can be made by determining that the mass is cystic and originates from the ovary, supplemented by ovarian tumor markers: HCG, AFP, etc., to further differentiate it from ovarian tumors. Due to high levels of hormones in infants such as gonadotropin releasing hormone (GnRH), FSH, LH, HCG and E2 all affect and stimulate the follicular development of the ovary, leading to the occurrence of ovarian cysts. And after birth, as the levels of some hormones decrease rapidly, ovarian cysts begin to fade away. Therefore most simple ovarian cysts can spontaneously subside within six months after birth. However, it should be noted that most scholars favor surgical treatment in the following cases: (1) for ovarian cysts with a direct diameter greater than 4-5.0 cm, because the cyst is prone to torsional necrosis (to the point of loss of that side of the ovary) and other complications such as compression of the intestinal canal, ureter or inferior vena cava, rupture and hemorrhagic peritonitis, or entrapment of the nucleus pulposus, among other complications; (2) if the cyst does not disappear or continues to increase in diameter under dynamic observation; (3) if the cyst continues to increase in diameter. (3) if the cyst has been twisted; (4) mixed cysts, containing solid components and high levels of tumor markers, such as ovarian teratoma, etc., surgery is considered. Surgery can be performed in two ways: minimally invasive laparoscopic or traditional open surgery.