retained fetal bone in infertile patients: two case reports

the prolonged retention of fetal bone structure is an uncommon condition after a previous abortion. we describe two cases with fetal bone fragment amongst 3589 hysteroscopies (0.05%) who had no complaint other than secondary infertility. in both patients hyperechogenic areas were found through transvaginal ultrasound and the bones were removed by hysteroscopy. despite meticulous evaluation during hysteroscopy some bones were not observed and were stable during the next sonography. according to the formation of fetal bones after 11 weeks of pregnancy; patients with secondary infertility who have a history of abortion that progressed beyond this time and endometrial hyperechoic areas by transvaginal ultrasound should be evaluated for any retained fetal bone. hysteroscopy should be performed under abdominal ultrasonography guide to ensure fetal bone tissue is entirely removed during a single surgery.