Pathogenesis of delayed ovulation

Reasons for poor fertility associated with delayed ovulation

1. Ageing of the oocyte(within the follicle), precocious resumption of meiosis
   1. failure of fertilisation
   2. poor developmental potential of the embryo
   3. early embryo mortality
2. Ageing of sperm
3. Changes in the oviduct environment- The passage of the zygote through the ovidct is delayed in a changed endocrine environment

Factors predisposing to delayed ovulation

The direct case of delayed ovulation is a delay in or an inadequate preovulatory LH peak.

The following can negatively influence the preovulatory peak , influencing follicular growth and oestradiol secretion:

• negative energy balance
• heat stress
• certain infections such as BVD and IBR
• subluteal levels of progesterone (treatment with progesterone/progestagen releasing devices, inadequate luteal function)