Synonyms in a broader sense
- Pill
- Contraception
- Condom
- Hormone bomb
- Post-coital contraception
Definition of the “morning after pill
Effectiveness
The effectiveness of the morning-after pill depends on the interval between taking it and sexual intercourse. Within the first 24 hours the pregnancy rate is 0.4%, but rises to 2.7% on the 3rd day. Thus, the reliability is 70-90%, depending on the time of taking the pill.
Mode of action
Recently, 2 different hormonal substances have been added to the morning-after pill. One is the chemically produced preparation Levonorgestrel, which mimics a hormone produced naturally in the body, the progestin, and the other is the preparation Ulipristal, which changes a hormone receptor. The mode of action of levonorgestrel (trade name: Duofem or Levogynon) is not fully understood.
However, the inhibition of ovulation (ovulation inhibition) has been reported as one of the main effects of levonorgestrel. This can be explained by the inhibition of the body’s own hormone LH (=luteinizing hormone), which is secreted in a part of the brain (pituitary gland) and normally causes ovulation in the second half of the cycle by increased secretion. From this it can be deduced that pregnancy cannot be prevented when ovulation has already occurred.
The implantation inhibition (= implantation inhibition) is explained by the hormone-induced premature transformation of the inner uterine lining (= endometrium), which then leads to a short withdrawal bleeding after the hormones have been discontinued and thus prevents the implantation of the egg (morning-after pill). Other approaches are that the increased progestin concentration leads to a tougher cervical mucus (similar to the way the minipill works), which hinders sperm migration. In addition, the pH value of the secretion also decreases, which reduces the mobility of the sperm.
The mode of action of Ulipristal (trade name: ellaone) consists in the occupation of the body’s own progesterone receptors. Progesterone (= yellow body hormone) is a sex hormone which is produced in the ovaries of women. The inhibition of the progesterone effect also leads to the prevention of ovulation and to the prevention of a change in the lining of the uterus necessary for implantation (=nidation) (morning after pill).
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