[Fertilization in vitro: ovulation induction and oocyte harvest]

Abstract

In vitro fertilization, the pregnancy rate obtained by transfer of embryo increases with the number of embryos transferred. For this reason, ovarian follicles are made to multiply and mature by means of various therapeutic patterns which stimulate ovulation. The conventional treatments with gonadotropins administered alone or combined with clomifene citrate have been superseded by GnR analogues-gonadotropin combinations. The effects of treatment are monitored by ovarian ultrasonography and by repeated measurements of serum oestradiol levels. This enables the HMG dosage to be adjusted and the injection of HCG, which completes follicular maturation, to be given at the right time. The oocytes, initially collected by coelioscopy, are now usually collected by transvaginal aspiration under ultrasonic guidance.