Understanding the Menstrual Cycle: Top Five Facts

Understanding the Menstrual Cycle: Top Five Facts

By Dr Neil Astill, Clinical Director at City Fertility Centre Brisbane Southside. Dr Neil Astill, specialist at City Fertility Centre Brisbane Southside

The menstrual cycle occurs within the female ovaries and uterus for the purpose of reproduction. It is a complex process controlled by many different glands and the hormones that these glands produce. It is essential for the production of eggs and preparation of the uterus for a pregnancy, and should occur monthly from puberty until menopause.

For many women, trying to conceive can be a challenging time and by learning to better understand your body’s menstrual cycle and to recognise the signs of ovulation, it may help you feel more in control. Here are a few of the top facts about the menstrual cycle:

1.Menstrual Cycles vary

The average menstrual cycle length can vary from 25 to 35 days. A menstrual cycle is the number of days from the first day of your last period to the first day of your next period.

2. A Menstrual cycle has four phases

The four phases of the menstrual cycle are:

The Follicular phase: where the ovarian follicles mature and prepare to release an egg.

Ovulation: is where a mature egg is released from a follicle.

The Luteal phase: where the remaining follicle that produced the egg now produces hormones to provide nutrition to an embryo should one be created and implant successfully.

Menstruation: is the elimination of the lining of the uterus (endometrium) and is usually a sign that pregnancy has not been achieved.

3. Ovulation is a female’s most fertile time of the month

Ovulation is when the egg is released from the ovary and is definitely a female’s most fertile time of the month.

The likelihood of conceiving is substantially increased if you have sexual intercourse in the three days leading up to and including ovulation, which are the most fertile days in your menstrual cycle. This is when the egg is moving down the fallopian tube waiting to be fertilised. The egg can survive for up to 24 hours after ovulation, while sperm can survive and fertilise an egg for two to three days in the fallopian tubes.

If you are wishing to conceive, you should have unprotected intercourse every two days throughout the female’s “fertile window”. This means that sperm are ready and waiting for the egg when the female ovulates. If you wait until after ovulation to have sex, it is likely you will have missed the opportunity to conceive that month.

4. Calculating your fertile window is vital

To calculate your “fertile window”, you need to know the length of the menstrual cycle (which can vary from 23 to 35 days or longer). So, if your cycle is 28 days, subtract 14 days from the first day of your last period to identify the day you are likely to ovulate.

If your cycles are irregular, or vary in duration each month, your ovulation date will be difficult to calculate. While ovulation urine tests may be useful, you may want to consider seeking further advice from your GP or a fertility doctor.

A Fertility Awareness Calendar can help you predict your ovulation date.

5. Irregular menstrual cycles can indicate a problem with ovulation

Irregular menstrual cycles may suggest a problem with ovulation. As previously mentioned, the menstrual cycle is determined by a complex interaction of hormones, so any hormone imbalance can make a period irregular. Although, in most cases, irregular cycles are not dangerous, it is important to determine what is causing the irregularity. There are several ways to help regulate menstrual cycles.


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