Introduction
Every woman can have unprotected sex due to various circumstances. Typical reasons for this are forgetting to take the pill or a torn condom. To prevent pregnancy nevertheless, there is the so-called “morning-after pill”.
It is also known as emergency contraceptive and can prevent pregnancy if taken promptly. The EllaOne®, whose active substance is Ulipristalacetat, is considered thereby in Germany as “means of the first choice”. Its more cost-effective alternative would be PiDaNa® with the active ingredient levonorgestrel. However, since both active ingredients can also cause some side effects, they should not be used as permanent contraception despite their good efficacy.
Female cycle: ovulation
In order to understand the effects of the emergency contraceptive pill, a short explanation of the female cycle follows. In a normal cycle (28 days duration) ovulation occurs between the 12th and 16th day of the cycle. For most women, ovulation takes place on the 14th day, i.e. in the middle of the cycle.
With the help of an ovulation calculator or ovulation calendar, the exact time of ovulation can be calculated. Some women may perceive ovulation as a short, stabbing pain in the area of the ovaries, but most women do not feel it. After ovulation, the egg is fertile for 12 to 24 hours, which means that pregnancy can occur when it comes into contact with sperm.
It is important to know that the average survival time of sperm is about 2-3 days. So if a woman had unprotected sexual intercourse a few days before or exactly on the day of ovulation, the possibility of pregnancy is given. For ovulation itself, the hormone LH (luteinizing hormone) is required.
Shortly before ovulation, its concentration increases enormously, so that the so-called LH peak (a peak LH concentration) occurs and thus ovulation occurs. After ovulation, the ruptured follicle begins to produce the hormone progesterone, which is responsible for creating ideal conditions for pregnancy. For example, progesterone causes the lining of the uterus to build up, into which the fertilized egg can implant. However, if the egg is not fertilised, other hormones (oestrogens) are produced in the course of the pregnancy, which break down the lining of the uterus and thus trigger menstruation.