A woman’s fertile period refers to the few days around her ovulation period in which there is a heightened chance of conception during copulation. On the other hand her safe period refers to the contrary, i.e. any other day in her cycle that she is not likely to conceive after copulation. For a woman to understand her fertile period and hence her safe period, she must first be aware of her cycle length and then be able to predict to a very good extent her next menstrual date. This is however only possible in women with regular menstrual cycles. This is because women with regular menstrual cycles ovulate frequently, regularly and in a predictable manner described as ovulatory cycles, in contrast to those with irregular cycles who ovulate occasionally if at all, irregularly and in an unpredictable manner, described as anovulatory cycles. For information on how to determine if your menstrual cycle is regular or not, please see NORMAL AND ABNORMAL MENSTRUAL CYCLES.



The concept of the fertile and safe period is based on the following facts;

1.  The male sperms live in the female reproductive tract for about 2 to 3 days after ejaculation and in some instances up to 5 days while the female ovum only lives for about 12 to 24 hours after ovulation.

2.  Because the luteal phase is fairly constant at about 14 days for all women, menstruation occurs approximately 14 days after ovulation in women with regular cycles. Therefore, menstruation= ovulation day + 14 days

3.  The follicular phase varies considerably among all women but less considerably in a woman with a regular menstrual cycle. As such, when subtracting the shortest cycle length from the longest cycle length in a six month period for a woman with a regular menstrual cycle, the difference should not be more than five days, otherwise the cycles are irregular and anovuatory.

From the above, we can deduce the following:

1,  Unless a woman has a normal or regular menstrual cycle, anticipating the likely ovulation day may not be possible.

2,  After calculating the average cycle length over a period of 6 months, subtracting 14 days from the average cycle length will provide the most likely day of ovulation. i.e. Average cycle length – 14 days = the most likely day of ovulation in your menstrual cycle.

3,  By subtracting and adding 2 to 3 days from and to the most likely day of ovulation within one’s menstrual cycle, one can anticipate the likely days of ovulation within a 6 month period putting in perspective the subtle variation in the follicular length anticipated not to exceed five days after subtracting the shortest cycle from the longest cycle in any woman ovulating regularly. In other words if the average cycle length is 28 days in a six month cycle granted all other criteria are fulfilled (see: NORMAL AND ABNORMAL MENSTRUAL CYCLE), her cycle length therefore may range from 26 days to 31 days or from 25 days to 30days of her cycle and she may ovulate on any days ranging from day 12 to day 17 if her cycle length is from 26 days to 31 days or from day 11 to day 16 if her cycle length is from 25 days to 30 days.

4,  While a woman is most fertile on her ovulation day, which can fall within a 5 day window, because the sperms can live for about 3 to 5 days in a woman’s genital tract and the egg or ovum can live up to about 24 hours after ovulation, it suffice that fertility is possible 5 days before ovulation, peaking at ovulation and ending 24hours after ovulation. i.e. Fertilization of the egg/ovum can occur if there is sex about five days prior to ovulation till about a day after ovulation.

5,  Due to the subtle variability in the ovulation period as mentioned above ( 2 to 3 days before and after the average ovulation day), a woman’s fertile window or period therefore can be said to be from about 7 to 8 days before the likely ovulation day to about 2 to 3 days after the likely ovulation day, giving a window of about 10 days. i.e fertile window = 7 to 8 days before likely ovulation day to 2 to 3 days after.

6,  The safe period is however, any other day outside this fertile window, i.e. any other day apart from about 7 days before the average ovulation date till about the 3rd day after the average ovulation date.

In addition to the above facts, women who are aware of signs and symptoms of ovulation may be able to pin down their most fertile period as close to their ovulation day as possible. To learn more about signs and symptoms of ovulation and how to predict ovulation period with these signs see SYMPTOMS, SIGNS AND PREDICTION OF OVULATION.

Although, women with irregular menstrual cycles are faced with a high chance of infertility due to anovulation, the calculation of a safe period or a fertile period in such women is virtually impossible, predisposing them to an unlikely but possible risk of an unanticipated and unwanted pregnancy due to the possibility of an irregular, unpredictable and occasional ovulation. Therefore, such women should seek a specialist to determine both the underlying cause of their condition for prompt and proper management and at the same time obtain proper contraception to avoid unwanted pregnancies.

Although the knowledge of the fertile period is good for all women desirous of pregnancy, timed intercourse only during the fertile period, is not encouraged for couples living together because it eventually makes intercourse mechanical and un-interesting as repeated anticipation of pregnancy at the end of each cycle, coupled with the high premium placed on child bearing on newly married couples in our environment, create a lot of psychological pressure, doubt and damage to the self esteem of many couples, especially women from this part of the world. On the contrary, having regular well spaced intercourse 3 to 4 times a week, on every other day is very effective as about 70% of couples will eventually conceive within one year of doing so with or without the use of timed intercourse during the fertile period. Having said this, all women are advised to know their fertile period, especially when frequent and regular intercourse is impossible, for example, couples living apart, so as to know when to time their intercorse. If after a year of trying to conceive a couple is unable to do so, it advisable that such couples should seek counseling from a gynecologist to unravel the underlying cause of their infertility. Finally using the safe period as a means of contraception requires a lot of discipline from both parties involved as its high failure rate is due to poor compliance to the principles explained above rather than to the failure of the method itself. For more information, please CHAT WITH OUR CONSULTANTS.