Improving oocyte maturation in vitro

Abstract

Introduction Successful infertility treatment, especially in vitro fertilization (IVF) and accompanying clinical and laboratory technologies, has to be one of the great medical success stories of the late twentieth and early twenty-first centuries. In the space of 35 years of development, assisted reproduction through IVF now contributes up to 4% of all births in developed nations, with these figures set to increase further due to the influence of increasing maternal age to first conception, lifestyle choices, and the exposure to environmental toxins. The success of current technology utilized in an IVF cycle is dependent on gonadotropic hormone hyperstimulation of the ovary to generate large numbers of mature oocytes (Figure18.1). Nevertheless, hormonal stimulation of the ovary by follicle stimulating hormone (FSH), or an analog, is associated with various risks and financial costs. These include: a health risk to women caused by severe ovarian hyperstimulation syndrome (OHSS), which affects 0.5–5% of gonadotropin-treated women [1]; a risk to oocyte and resulting embryo health (e.g., embryo an-euploidy [2] and perturbed genomic imprinting [3]); and a significant financial burden placed on couples and/or healthcare providers due to the cost of the gonadotropin treatment. Furthermore, FSH has dose-dependent adverse effects on subsequent embryo quality, endometrial protein expression, and pregnancy rates in adult, cycling female mice [4, 5]. Therefore, safe, reliable alternatives to the current clinical IVF practices that remove the need for hyperstimulatory FSH treatment, accompanied with increased treatment options for women, is highly attractive. This would be particularly so for women who suffer from the very prevalent condition of polycystic ovaries (estimated to be around 20% of women of reproductive age), who are particularly susceptible to OHSS and as a result, at times have limited IVF treatment options.