There are several methods to detect ovulation and thereby determine when it is necessary to abstain. This includes
Although an egg can be fertilized only for about 12 hours after ovulation, sperm can fertilize an egg up to 5 days after coitus; therefore an intercourse of nearly 5 days before ovulation can lead to pregnancy. Therefore, natural methods demand the renunciation of sexual intercourse from the 5th day before ovulation. There are several methods to detect ovulation and thereby determine when it is necessary to abstain. These include calendar method Two-day (ovulation) method Symptothermalmethode The calendar method attempts to predict the time of ovulation due to menstrual data and is only suitable for women with regular menstrual cycles. Ovulation usually occurs about 14 days before the start of menstrual bleeding. Therefore, the interval of abstinence is calculated during the menstrual cycle, by subtracting 18 days from the duration of the shortest cycle during the previous 12 months and 11 days from the longest cycle. When the cycles vary, for example 26-29 days, in each cycle a abstaining from day 8 through day 18 is required. The greater the variability of cycle length, the longer the abstinence must last. “CycleBeads” (a string of colored beads that represent the days of the menstrual cycle) can be used to determine the fertile days. The two-day (ovulation) method based solely on the judgment of the cervical mucus. Cervical mucus may be absent for several days after menses. the mucus occurs again, it is rather flaky, thick and inelastic. Then the amount of mucus increases, it becomes thinner, clearer and more flexible than before. It resembles raw egg whites and pulls his fingers threads. Sexual intercourse is completely eliminated during the menses (because the cervical mucus can not be verified). He is allowed to days when the cervical mucus entirely missing, but the coital frequency is limited to every second day (so that the semen is not confused with the cervical mucus). Sexual intercourse is from the date on which the cervical mucus after menses is available again, avoided altogether to 4 days after the biggest mucus production. Sexual intercourse is possible without restriction from 4 days after the largest production of mucus to the beginning of menses. A change in the cervical mucus shows the ovulation of reliable than body temperature. The Symptothermalmethode combines the measurement of basal body temperature (which increases after ovulation), the evaluation of the cervical mucus and the calendar method. Sexual intercourse is avoided on the first day of the calendar method to 3 days after acceptance of the Zervixschleimmenge and increase in temperature. The Symptothermalmethode has a lower pregnancy rate than the 2-day method under ideal application (based on the cervical mucus) or as the calendar method (with or without “CycleBeads”). However, the pregnancy rates in these methods under typical use is high, so that these methods are not recommended women who want to avoid pregnancy in every case. The lactational amenorrhea is a further natural contraception method. It is based on the physiological Inferilität after childbirth in women who breastfeed exclusively (or almost exclusively) and the menses has not yet occurred again. The suction of the infant inhibits the release of hormones that are necessary for the stimulation of ovulation. Without ovulation, there can be no pregnancy. This method is 98% sure if the following criteria are met: The infant is <6 months old. Breastfeeding is the primary type of infant feeding (addition of baby food, or solid food or pumping breast milk reduces the effectiveness). It is breastfed at least every 4 hours during the day and every 6 hours during the night. The menses has not yet been reinstated (amenorrhea).