Medical Q&As

Short cycle - affect fertility?

I am trying to conceive for the first time. I am 37years old and my partner is 40 years old. I have just had a period after 18 days; my normal cycle is between 25 and 28 days, with heavy bleeding for 5 or 6 days. Should I be worried about the short cycle? This is the second time in about 8 months that I have had a short cycle.

In answering your question I want to discuss the events that occur during the ovulation cycle, which is a key stage in the monthly cycle. The ovulation cycle refers to those physiological events that occur around the time of ovulation or egg release. It is divided into two phases; the follicular phase and the luteal phase. The follicular phase refers to those events leading up to the release of the egg and the luteal phase refers to the events that occur after egg release. On average the follicular phase lasts 14 days and the luteal phase can last from 11 to 16 days. When a woman has a short menstrual cycle it is because of shortening of the luteal phase. The term “luteal” is derived from corpus luteum, which is the empty sac that is left on the surface of the ovary when the egg is released. The corpus luteum has a very important role in that it is responsible for progesterone production in the second half of the menstrual cycle. If the luteal phase is shorter than normal this can interfere with the process of implantation. Therefore conception could have taken place and the pregnancy did not proceed because of failure of implantation. However, I want to enter an extremely important caveat here; most fertile women have the occasional short cycle. I would consider the two short cycles you have described to be normal but I am conscious of your age and the fact that you have not conceived previously. To repeat again, the experience you have described is normal, but if you should experience consistently short consecutive menstrual cycles it would be worth attending your GP for further assessment.