Trying for a Baby? See What You Should Know About Your Fertile Window

When it comes to getting pregnant, timing is everything because a woman’s fertile window is pretty short. Knowing where you are in your cycle and when you are due to ovulate will help you make the most of that small window of opportunity, which differs from one woman to the other.

What is the fertile window?

It refers to the days in a woman’s menstrual cycle when pregnancy is possible. Pregnancy is technically only possible during the five days before ovulation through to the day of ovulation.

These six days are the ‘fertile window’ in a woman’s cycle, and reflect the lifespan of sperm (5 days) and the lifespan of the ovum (24 hours).

If a woman has sex six or more days before she ovulates, the chance she will get pregnant is virtually zero. If she has sex five days before she ovulates, her probability of pregnancy is about 10%.

The probability of pregnancy rises steadily until the two days before and including the day of ovulation.

At the end of the ‘fertile window’, the probability of pregnancy declines rapidly and by 12-24 hours after she ovulates, a woman is no longer able to get pregnant during that cycle.

For those women who are not aware of their ‘fertile window’ or when they ovulate, sexual intercourse is recommended every 2 to 3 days to help optimise their chance of conceiving.

The likelihood of actually becoming pregnant is dramatically increased if you have intercourse in the three days leading up to and including ovulation. If a woman has sex on any of these three days, she has a 27-33% chance of becoming pregnant.

So, what is ovulation?

Ovulation is when a mature egg is released from the ovary, moves down the fallopian tube, and is available in the fallopian tube to be fertilised.

Tracking your ovulation

• Work out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins.
• Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14.

Remember the ‘fertile window’ is the six days leading up to and including ovulation.

The three days leading up to and including ovulation are the most fertile. Depending on your cycle length the most fertile days in the cycle varies:

• If you have 28 days between periods, ovulation typically happens on day 14, and the most fertile days are days 12, 13, and 14.
• If you have longer cycles, say 35 days between periods, ovulation happens on day 21 and the most fertile days are days 19, 20, and 21.
• If you have shorter cycles, say 21 days between periods, ovulation happens on day 7 and the most fertile days are days 5, 6, and 7.

How do you know you’re ovulating?

Women’s cycles can vary and are not always as regular as clockwork, so to know that you are ovulating and on which day of your cycle you are ovulating, observe your fertility signs throughout your cycle and record them on a chart.

The most accurate methods of working out when ovulation is about to occur are:

• Keeping an eye out for changes in your mucus. Around the time of ovulation, you may notice your vagina’s mucus is clear, slick and slippery, the consistency of egg white. This is the best sign of when ovulation is actually happening. It’s prime time for action.
• Using an ovulation predictor kit. You can start testing with your ovulation predictor kit a few days before your estimated day of ovulation. Subtract 17 days from your average cycle length and start testing from this day of your cycle, e.g. if you have a 28 day cycle, you would start testing from day 11. A positive result means you are going to ovulate within the next 24 to 36 hours.
• Record your basal body temperature (BBT) each day before getting out of bed. A special basal body temperature thermometer will ensure accurate measurement. Your BBT rises about half a degree Celsius after ovulation has occurred. By charting your temperature, it’s easy to see when the rise in temperature and ovulation happens. This can help you work out your own pattern of ovulation. However, because at that stage ovulation has already passed, it does not help you pinpoint the fertile window but may guide you for next month. Read more about ovulation signs here.

Source: yourfertility