Yes, Marion. Irregular periods (those that fall outside the normal 27–32 day range) are often caused by irregular ovulation (the release of eggs from the ovary) or a complete lack of ovulation (oligo-ovulation and anovulation, respectively). These are some of the most common causes of infertility.
Subfertility is defined as the failure to conceive after regular sexual intercourse for one or two years in the absence of any known reproductive disease. This implies that regular ovulation is necessary for conception.
In the general population, up to 90 per cent of couples will conceive after regular, unprotected sexual intercourse within two years. However, if menstrual cycles are irregular, conception may not occur because ovulation signifies egg release from the ovary, which typically occurs 14 days before the first day of menstruation. For fertilisation to take place, a viable sperm must be present when the egg is released.
Missing or irregular periods suggest that ovulation may not be occurring consistently. If an egg is released after a delay, there is a possibility that sperm may no longer be available to fertilise it. When this condition persists, it can lead to infertility in one of its forms.
