The various forms of hormonal contraception
- Estrogen and progesterone, combined or sequentially in pill form
- Progesterone alone in the form of pills
- Progesterone alone in the form of an implant
- Progesterone given off by an intra-uterine system
How the hormonal method of contraception functions
- They lower FSH secretion so that normal follicle maturation does not occur and no LH peak happens. This effect is mainly due to estrogen, but progesterone can also inhibit ovulation when ingested in high dosages.
- They transform the uterine endometrium so it becomes pseudoatrophic, thereby making an implantation practically impossible, should an ovulation and fertilization take place.
- They modify the cervix mucous so that it becomes less permeable for sperm cells (this effect is mainly due to the progesterone).
Most pills are monophasic, i.e., they always contain the same amounts of estrogen and progesterone for the whole cycle. Nevertheless, bi- and triphasic pills also exist that attempt to imitate the cyclic physiological changes. The ideal pill yields the lowest amounts of estrogen and progesterone but, at the same time, is an efficient contraceptive with minimal side effects.
The main side effects
- Thrombo-embolisms: primarily due to the alteration of coagulation factors that are induced by the estrogen. Risk factors are age (for those older than 35), arterial hypertonia and tobacco abuse
- Myocardial infarction and cerebral insult, especially with smokers that are older than 35. The arterial disease is primarily due to the effects of progesterone. This lowers the HDL-2 value (high density lipoprotein) that has a heart protective activity.
- Hypertonia: blood volume and angiotensin secretion are elevated.
- Some studies have suggested that patients who are older than 25 and take progesterone for a long time have an increased risk of breast cancer. Oral contraceptives taken for an extended period of time are also supposed to increase the risk for cervical carcinomas.
Less prominent side effects
- Estrogen: Bleeding, feeling bad, aching breasts, headaches
- Estrogen + progesterone: Weight gain, absence of menstruation bleeding
- Progesterone: Acne, depression, lowering of libido.