Sunday, July 25, 2010 by: Louanne Piccolo, citizen journalist
Natural family planning depends on a couple`s ability to recognise the phases of a woman`s menstrual cycle and to calculate when ovulation is most likely to occur. In this way, they can avoid an unwanted pregnancy.
How Reliable are Natural Birth Control Methods?
For a natural method to be effective a woman`s menstrual cycle must follow the same pattern month after month so that she can rely on the regularity of her fertile period. A woman with a regular menstrual cycle will ovulate approximately fourteen days before her following period. An egg has 24 hours to be fertilized before dying but sperm can live for up to seven days after ejaculation. Therefore, a woman with an irregular cycle may have difficulty in identifying the phases when she should avoid unprotected sex.
Natural Birth Control Methods
Being able to pinpoint the period of ovulation is the most important part of natural family planning methods. Two methods for calculating ovulation are:
The Basal Body Temperature Method: Progesterone makes a woman’s body temperature rise, to half a degree Celsius higher than normal, the day after ovulation has occurred. A woman will easily recognise this slight rise in temperature if she measures her temperature, using the same thermometer every day, immediately after waking and before getting out of bed.
This method is entirely natural making it a good choice of contraception for women wishing to avoid the contraceptive pill. However, it may be difficult to maintain the habit of temperature taking every morning and even a slight cold may cause temperatures to rise resulting in a false reading.
The Calendar Method: To use this method effectively, the amount of days between the beginning of one period and the next must be jotted down for a period of six months. Eighteen days are subtracted from the shortest interval between periods and eleven days from the longest interval between cycles. Calculations could look like this: the shortest interval is 25 days – 18 = 7 and the longest interval is 30 days – 11 = 19. The fertile phase for a woman with this data would be from day seven of her cycle to day nineteen. During this period, unprotected sex could result in an unplanned pregnancy.
For this method to work, data must be recorded every month, without fail, for six months. The calendar method requires couples to abstain from sex for one to two weeks per month unless they use other forms of contraception during the fertile period.