Whether you are thinking about trying for a baby or trying already, gaining a better understanding about how your body works can be a big help. One in two couples could be trying to conceive on the wrong days of the womanâs cyclei, so weâve put together some information to help you understand your menstrual cycle and the ovulation process. Ovulation happens when hormone changes trigger your ovaries to release an ovum (egg) â usually 12 to 16 days before your next period starts. You are most fertile on the few days leading up to and including the day of ovulation.
The ova (eggs) are contained in your ovaries. During the first part of each menstrual cycle one of the eggs will be prepared for release from the ovary. As you approach ovulation, your body produces more estrogen. This hormone causes the lining of your uterus to thicken and also creates a sperm friendly environment. The higher estrogen level triggers a sudden rise or âsurgeâ in luteinising hormone (LH) which then triggers the release of the egg from your ovary, this is called ovulation.
Normally, ovulation occurs 24 to 36 hours after the LH surge, and you are at your most fertile on the day of the LH surge and the day after.
The egg survives for up to 24 hours after ovulation which is when it can be fertilised. If fertilisation does not occur, the levels of the fertility hormones decline and the next cycle starts with the shedding of the thickened uterus lining (period).
Although the egg only survives for up to 24 hours, sperm can survive for up to five days. That is why you can still conceive even if you have sex 4 -5 days before the egg is released.
i Johnson SR, Foster L and Ellis J. Human Reproduction (2011) 26: i236