This chapter describes the progress that has been made in the development of in vitro ovarian follicle culture systems, and highlights the importance of maintaining follicular architecture to facilitate follicle growth and oocyte development. The follicle is the main reproductive unit of the ovary, and is composed of a single oocyte and its surrounding somatic support cells. The interaction between follicle cells and the surrounding extracellular matrix (ECM) is essential for facilitating intercellular communication within an individual follicle. The goal in ovarian follicle culture, particularly with follicles from larger mammalian species, is to mimic the complex molecular, functional, and structural changes that occur in vivo in order to produce a fully mature, fertilizable egg in vitro. The chapter reviews the various systems that have been developed for the in vitro culture of preantral follicles. Initial work focused on achieving oocyte growth in vitro relied on adherent two-dimensional (2D) culture systems.

Clinical manifestation of anovulation is oligomenorrhea or amenorrhea. Patients with hyperandrogenemia and polycystic ovaries (without ovulation disorders) and patients with polycystic ovaries and ovulation disorders (without hyperandrogenism) may now be included in polycystic ovary syndrome (PCOS) diagnosis. The majority of anovulatory patients (about 80%) will have normal serum concentrations of estradiol (E2) and follicle-stimulating hormone (FSH) and a small proportion (approximately 10%) decreased concentrations of both hormones. Traditionally, ovulation induction treatment in normogonadotropic anovulation is started with an antiestrogen (CC) and, in case of treatment failure or absence of conception, this is followed by exogenous FSH. The most serious complications resulting from ovulation induction are caused by the limited control of follicular development. Increased availability of genetic profiles will be helpful to accomplish a more patient-tailored approach by identification of beneficial subgroups for certain interventions.