Engineering as a Tool in Assisted Reproduction: An Investigation Using Mathematical Modelling of Oxygen Transport in the Ovarian Follicle

The key objective of any Assisted Reproductive Technology (ART) is to provide infertile couples with the maximal chance of producing healthy offspring and there is a large body of research within this field directed toward this objective. However, despite this volume of research attention, the success rates of many procedures such as In-Vitro fertilization (IVF) have improved little since their inception. Engineering principles have not been widely applied to ART and, as a result, it appears that there is great potential for engineering to make a contribution to this field. The objectives of this work were to demonstrate the usefulness of engineering principles in this field via the example of modelling oxygen transport in the preovulatory human ovarian follicle. The results show mathematical relationships between follicular fluid dissolved oxygen levels, follicular vascularity and the developmental potential of the oocyte can be described. These relationships are shown to be consistent with findings reported in the literature. Significant results include the emergence of cut off levels of both follicular vascularity and follicle size below which all eggs will be starved of oxygen. Based on current model parameters these cut off levels are predicted to range from 22–40% and 3.5–4.3 ml (19.0–20.3 mm follicle diameter) for follicle vascularity and volume respectively. These results serve to highlight the potential contribution of engineering in general to ART. The implications of these findings are also discussed as are future improvements for modelling mass transport in the ovarian follicle.