Generality
The term "contraceptives" is used to indicate the set of drugs and devices used to prevent the onset of a pregnancy.
- Contraceptive methods of the hormonal type, among which we find the oral contraceptives, the injectable contraceptives, the contraceptive patch and some types of intrauterine devices;
- Barrier contraceptive methods, among which we find the condom and other types of intrauterine devices.
In the following, these contraceptive methods will be briefly described, with particular attention given to hormonal contraceptives.
Oral contraceptives
As mentioned, oral contraceptives fall into the category of hormonal contraceptives.
In turn, oral contraceptives can be divided into two groups:
- Oral contraceptives in combination;
- Progestin-based oral contraceptives (often referred to as "mini-pill").
As you can easily guess, oral contraceptives in combination are drugs that contain a combination of different active ingredients. More specifically, they contain a combination of an active ingredient of the estrogenic type and an active substance of the progestin type.
In contrast, oral progestagens do not contain the estrogenic component, but only the progestin component.
They belong to the category of hormonal contraceptives for oral use, active ingredients such as ethinylestradiol (Ginoden®, Loette®, Arianna®, Belara®, Yasmin®, Yasminelle®), estradiol (Zoely®), levonorgestrel (Loette®, Egogyn®), gestodene (Ginoden®, Arianna®, Milavane®), drospirenone (Yasmin®, Yasminelle®) and desogestrel (Cerazette®, Mercilon®, Minulet®).
Action mechanism
The estrogen contained within oral contraceptives exerts its contraceptive action by suppressing the release of follicle stimulating hormone (or FSH), thus preventing the formation of a dominant follicle during the follicular phase of the menstrual cycle.
The dominant follicle, in fact, is responsible for the synthesis of estradiol which, in turn, sends a signal to negative feedback to the hypothalamus. All this results in an inhibition of the secretion of gonadotropins, which in this way prevents the maturation of other follicles. Therefore, estrogen is able to prevent this series of events, but not only. In fact, the estrogenic component is also responsible for maintaining endometrial stability.
The progestin, on the other hand, exerts its contraceptive action by blocking ovulation by inhibiting the synthesis of luteinizing hormone (or LH) in the middle of the menstrual cycle. Furthermore, the progestin component is also able to induce a thickening of the cervical mucosa, which hinders the passage of the sperm into the endometrial cavity and is also capable of transforming the endometrium into a hostile environment for embryo implantation.
Side effects
The main side effects produced by the estrogenic component are those of the cardiovascular type; in fact, estrogen increases the risk of developing venous thromboembolism, acute myocardial infarction and stroke.
The main undesirable effects caused by the progestin component, on the other hand, are the increase in blood triglyceride levels and the decrease in serum HDL levels. Therefore, if the so-called mini-pill is used, the risk of onset of cardiovascular effects is greatly reduced since there is no presence of estrogen.
However, for more information regarding the aforementioned side effects, we recommend reading the articles dedicated "Contraceptive pill and blood pressure" and "Contraceptive pill and cholesterol".
Transdermal contraceptive patches
Transdermal contraceptive patches also fall into the category of hormonal contraceptives, but unlike oral contraceptives, transdermal patches are long-acting pharmaceutical formulations. In fact, these patches, once applied, slowly release the active principles of estrogenic and progestin type.
More specifically, these active ingredients are generally ethinyl estradiol and norelgestromin (Evra®).
The patch must be applied on an arm, on a buttock or on the abdomen and must be replaced once a week (always on the same day) for three consecutive weeks. At the end of these three weeks it is necessary to observe a break of a week, in order to allow suspension bleeding.
Moreover, it is good to remember that - although it is well tolerated - the contraceptive patch may not be effective in patients with a body weight above 90 kg.
Action mechanism
Since they are hormonal contraceptives, the mechanism of action by which the active ingredients contained in the transdermal patches exercise their contraceptive activity is the same as described for the aforementioned oral contraceptives.
Side effects
The main side effects that can occur following the use of transdermal contraceptives are: nausea, headache, abdominal pain, breast pain and irritation at the site where the patch is applied.
Injectable contraceptives
In some cases, the doctor may decide to resort to long-term contraception through the use of injectable contraceptives, which can be either in combination, or progestogen type.
More in detail, both pharmaceutical formulations containing a combination of medroxyprogesterone acetate and estradiol cipion, and pharmaceutical formulations containing the only active substance of the progestagen type, such as medroxyprogesterone acetate (Perlessa®, Sayanaject), are commercially available.
The mechanism of action of these drugs is similar to that described for oral contraceptives.
Also the side effects are similar to those deriving from the use of oral contraceptives and consist of: headache, breast tenderness, decreased libido, increase in body weight.
However, in addition to the aforementioned undesirable effects, the injectable progestogen contraceptives may also increase the risk of irregular and abundant bleeding, amenorrhea and infertility that may persist for a long time after the last injection.
Implantable contraceptives
To this particular category of contraceptives belong both surgically implantable contraceptives (such as hormonal sticks ), and some types of intrauterine devices (or IUD, from the English "Intra-Uterine Device"), such as the hormonal spiral that releases a contraceptive in the body progestin and like the copper-coated spiral.
In particular, the latter type of device exerts contraceptive activity through mechanical irritation of the endometrium. In this way an unfavorable inflammatory environment is created for sperm and ovules, which does not allow the embryo to be implanted.
All these devices must be implanted (in the case of sticks) or inserted (in the case of spirals) only and exclusively by a medical expert in the field.
Side effects
The undesirable effects caused by the use of implantable hormonal sticks are the same as those described for oral progestogen-type contraceptives.
As for spirals, on the other hand, they are generally well tolerated, but in some cases they can give rise to serious complications, such as infections and ectopic pregnancy.
Contraceptive Ring
The contraceptive ring, similarly to what happens for the spirals, must be inserted in the vagina, inside which it will then release the active principles (estrogen and progestin) contained in it. Generally, these active ingredients are ethinyl estradiol and etonogestrel (NuvaRing®).
However, no medical attention is required for the insertion procedure of this device. Therefore, the ring can be safely inserted and removed by the same patient.
The mechanism of contraceptive action and the side effects resulting from the use of the contraceptive ring are similar to those previously described for oral contraceptives in combination.
In any case, for more information on this, see the articles dedicated to "Contraceptive Ring" and "Contraceptive Ring: Advantages and Disadvantages".
Contraceptive methods Barrier
The barrier - or mechanical - methods of contraception are contraceptive devices that perform their action by preventing direct contact between the egg cell and the spermatozoa.
Among the various devices belonging to this category we recall the condom, the contraceptive diaphragm (to be used preferably in association with spermicides), the cervical cap and the female condom .
This type of contraceptive will not be addressed in this article. Therefore, for more in-depth information on this, see the articles on this site: "Mechanical contraceptives - Barrier methods", "Condom - Condom", "Contraceptive diaphragm", "Cervical hood" and "Female condom" .
Emergency Contraceptives
The term "emergency contraception" is used to indicate a method that is able to prevent the onset of pregnancies following unprotected sexual intercourse, or following the failure of a contraceptive method (such as, for example, the breaking of the condom).
This type of contraceptive therapy can be sufficient on a single contraceptive agent, as in the case of the so-called "five-day pill after" based on ulipristal acetate (EllaOne®) and as in the case of the known "morning-after pill" containing levonorgestrel ( NorLevo®); or it can be based on an estrogen-progestin combination.
The most common side effects resulting from the use of this type of contraceptive consist of nausea and vomiting.
In the event that the patient cannot take hormonal contraceptives, then the doctor may decide to intervene by implanting a copper spiral within five days of unprotected intercourse or ovulation.
