First pregnancies after intravaginal transport and partial zona dissection of human oocytes

Abstract

We report on 72 couples with previous failure of fertilization during several trials of conventional IVF. For the present study, a part of the aspirated oocytes was subjected to partial zona dissection before insemination, thereby achieving 7 pregnancies during 104 cycles. Normal in vitro insemination of the remaining zona-intact oocytes was unsuccessful again. Because microinsemination techniques, in contrast to routine IVF, are not yet offered by many clinics, we developed the following new concept: hormonal stimulation, sonographic control of follicular growth, aspiration of oocytes, and sperm preparation were performed at the usual place (Munich), whereas partial zona dissection and control IVF were accomplished in another laboratory (Ulm). To transport the gametes between these two institutes, we modified the previously reported intravaginal culture of inseminated oocytes by transferring oocytes and spermatozoa into separate plastic capsules. In our view, this procedure offers an opportunity for infertile couples living too far away from a microinsemination center to afford long daily journeys or even several overnight stays just for superovulation treatment. The fertilization and PRs in our study are comparable with those reported in the literature.