Prevention of pregnancy (from Latin contraceptio) can be temporary or permanent – sterilization (sterilisatio). There is a wide variety of contraceptive methods and combinations between them. However, in general, four groups can be divided – natural, barrier, intrauterine and hormonal. 1. Natural methods of contraception Calendar method Through it you can make an assumption when ovulation is expected to occur, and in most cases, with a 28-day cycle, it is believed that ovulation will occur on the 14th day, that is, in the middle of the cycle. An egg is known to be fertile for only 24 hours, and sperm are fertile for 5 to 7 days. Of course, not all women have a 28-day cycle – menstruation occurs on the 28th day. There are women with shorter and longer menstrual cycles, which makes the method quite ineffective. NEWS_MORE_BOX Basal temperature measurement method The measurement is done in the morning before getting out of bed, and it is most appropriate to measure the rectal temperature. When ovulation occurs it increases as impulses are sent to the thermoregulatory center in the medulla oblongata due to rising progesterone levels and entry into the luteal phase of the cycle. According to this method, sexual contact is considered safe after three consecutive days in which a higher basal temperature is measured. Billings method for examining the quantity and quality of cervical mucus As ovulation approaches, cervical mucus becomes more watery, transparent, stretchy, “staining” underwear. If a woman’s cervix is ​​examined with a speculum during this period, the so-called “pupillary” phenomenon – the cervical canal is open and spermatozoa can easily pass through it, and this process is greatly facilitated by the watery cervical secretion. After ovulation, due to the increased synthesis of progesterone, the cervical secretion becomes thick, then almost disappears. The method is of low efficiency, but women, knowing themselves and knowing this feature that accompanies ovulation, can avoid sexual contact in this period. Interrupted sexual intercourse – coitus interruptus This method is based on stopping the sexual act immediately before ejaculation. The method requires a lot of self-control on the part of the man, which is sometimes related to the incomplete satisfaction of the partners. Unfortunately, it is only applicable in 50% of couples because there is a large percentage of men with premature ejaculation. In addition, the ejaculate can get close to the entrance of the vagina – introitus vaginae and spoil the method. Lactational amenorrhea The method is based on the fact that during breastfeeding, the secretion of prolactin from the posterior lobe of the pituitary gland increases, which suppresses the “maturation” of the follicle and ovulation. This also explains why women with high prolactin levels and the desire to get pregnant have failure to conceive. Breastfeeding should be at intervals of no more than 4 hours. during the day.However, some women may also menstruate as well as ovulate while breastfeeding. For this reason, the method is not reliable enough.