By Jackie

The majority of women have heard that the average length of a menstrual cycle is 28 days. But what if your menstrual cycle is longer or shorter than the average? Most women don’t care if their cycle is a few days off. However, if a woman is trying to conceive, knowing what is “normal” and what isn’t can make a big difference in conception efforts.

A study recently published in Fertility and Sterility examined the menstrual cycles of 167 women. In total, the researchers followed 459 nongestational (not pregnant) and 111 gestational menstrual cycles (pregnant). They found these interesting facts:

• Menstrual cycles were 27.7 days, plus or minus 2.4 days, in length. This means that for some women, their period came as early as 25.3 days and as late as 30.1 days.
• LH peaked at 14.7 days, plus or minus 2.4 days. This means that the presumed ovulatory window began as early as day 12.3 and as late as day 17.1.
• For women who became pregnant, implantation occurred (measured by first day of sensitive detection of hCG) on day 24.6, plus or minus 3.1 days.

The researchers reported that their findings were normal for menstrual cycle length, but that that there data on implantation was different from previously published data. If you are currently trying to become pregnant and your menstrual cycle falls outside of these parameters, you should speak with a gynecologist. Furthermore, if you have been trying for over a year with no success, you should also speak with a gynecologist who can complete a thorough blood work-up.

Curious to learn more about the menstrual cycle and fertility? Read Menstrual Cycle Length and Fertility, which discusses a study that found menstrual cycle length may correlate with fertility.