Last reviewed 01/2018

  • ovulation occurs as a result of a surge in levels of lutenizing hormone (LH) which in turn is caused by a rise in the level of oestrogen (oestradiol) in the peripheral circulation
  • the oestradiol surge is produced by the follicle remaining at the end of the follicular phase
  • meiosis is completed in the oocyte as a result of the mid-cycle surge in LH and, to a lesser extent, follicular stimulating hormone (FSH). Also, the follicle is stimulated to produce prostaglandins and progesterone. The oocyte is released from its attachments to surrounding granulosa cells via prostaglandins and enzymes activated by the LH/FSH surge.