Effects On Mature Mouse Oocytes Of Ultrasound Treatment Applied Before Invitro Fertilization

Although ultrasound is becoming widely used for monitoring follicular maturation and for oocyte recovery in IVF, there is still need for information about its possible effects on fertilisation, development and even implantation. In this paper, we report our findings on the effect on ovulated mouse oocytes of low-power ultrasound applied before IVF, culture and transfer. Pulse ultrasound was delivered at 3.5 MHz for one hour by a transducer with an average power output of 4.32 mW/cm2, to recently ovulated mouse oocytes. IVF and culture were performed in Whittingham's T6 medium supplemented with bovine serum albumin. No difference was observed between control and sonicated eggs in terms of developmental rate and speed. After 102 h. of culture, expanded blastocysts (75% in both group) were transferred to recipient females which were at day 3 of pseudopregnancy. These animals were autopsied at day 15. Although overall rates of implantation did not differ, there was a statistically significant increase of the number of resorption sites in the ultrasound-treated group (p