Influence of Early Pregnancy Termination by Focused Ultrasound Beams on Menstrual Recovery of Macaques

Objective To explore the effects on macaques' menstrual recovery after terminating early pregnancy by focused ultrasound beams (FUB)Methods FUB was used to terminate early pregnancy in 5 macaques with gestation duration ranging from 37-66 d. Two circles after the recovery of menstruation, color Doppler flow imaging (CDFI) and magnetic resonance imaging (MRI) were used to estimate the shape, size and blood flow of uterus, and pathological examinations were performed to check against any lesions to uterine endometrium and ovary.Results Forty days after FUB abortion, menstruation recovered and the volume and duration of each macaque's menstruation were not changed compared with those before gestation. CDFI and MRI suggested that the siz.e and shape of uterus were normal.The endometrial line was clear and no lesions were found in adjacent organs.Conclusion FUB termination of early pregnancy in macaques did not damage their ovarian tissue and had no influence on subsequent menstrual recovery.