Significance and functions of contraceptive use
Modern contraception addresses not only the task of preventing unwanted pregnancy but also performs a number of crucial medical functions. First, it radically reduces the incidence of abortions, which remain a leading cause of miscarriage, gynecological pathologies, as well as maternal and perinatal mortality. Second, contraception methods make it possible to consciously regulate birth rates: to plan conception taking into account the health status of the partners and to maintain optimal intervals between childbirths.
In addition, many agents possess pronounced protective properties. They provide oncoprotection and gynecological protection by reducing the risk of developing malignant neoplasms, pelvic inflammatory processes, and even postmenopausal osteoporosis. Finally, contraceptives provide a powerful therapeutic effect and are actively used in treatment regimens for infertility, menstrual cycle disorders, and ovarian apoplexy.
Classification and efficacy evaluation
The universal criterion for evaluating the reliability of any contraceptive is the Pearl index. This indicator demonstrates the number of pregnancies that occurred in 100 women during one year of continuous use of a specific method.
In modern gynecological practice, there are five main groups of contraceptive methods:
- Intrauterine;
- Hormonal;
- Barrier;
- Natural;
- Surgical (voluntary sterilization).
Intrauterine contraception (IUD)
The insertion of special devices directly into the uterine cavity is one of the most popular methods in Russia, Asian countries (especially China), and Scandinavia.
The history of the method dates back to antiquity, but the first documented prototype was proposed in 1909 by the German gynecologist Richter — it was a silkworm gut ring fastened with metal wire. Later, the gold or silver "Ott ring" with an internal disk appeared. After the official ban of the method in 1935, a real breakthrough occurred in 1962, when Lippes created a flexible plastic design in the shape of a double Latin letter "S" (Lippes loop). Its main advantages were the possibility of insertion without significant cervical dilation and the presence of a nylon thread for convenient removal.
Today, all IUDs are divided into two groups:
- Inert (non-medicated): simple plastic devices of various shapes. In 1989, the WHO called for abandoning their use due to low reliability and a high risk of complications.
- Medicated: plastic bases of various configurations (in the shape of an umbrella, loop, number "7", or letter "T"), enriched with active substances. The addition of metals (copper, silver) or hormones (levonorgestrel) dramatically increases contraceptive efficacy and reduces the frequency of adverse reactions.
In the Russian Federation, the following models are most commonly used:
- Multiload Cu 375: an F-shaped copper-bearing IUD with barbs for secure retention in the uterine cavity. The metal surface area is 375 mm², designed for 5 years.
- Nova-T: a T-shaped copper-bearing contraceptive (copper winding area 200 mm²), duration of use is 5 years.
- Copper T 380 A: a T-shaped model with a high copper content, inserted for 6–8 years.
- Mirena intrauterine system: a T-shaped hormonal contraceptive combining the properties of intrauterine and hormonal contraception. Equipped with a cylindrical reservoir with a semipermeable membrane that releases 20 mcg of levonorgestrel daily. Duration of action is 5 years.
Mechanism of action of intrauterine devices
The action of IUDs is complex in nature and divided into two directions: prevention of fertilization itself (contraceptive effect) and prevention of implantation if cell fusion has nevertheless occurred (abortifacient effect).
Contraceptive action is ensured by:
- Reduction of sperm activity and sperm death in the uterine cavity.
- A pronounced spermatotoxic effect, which is significantly enhanced by the addition of copper.
- Increased activity of macrophages, which begin to phagocytose spermatozoa that have entered the uterine cavity.
- Thickening of cervical mucus under the influence of progestogens (specific to hormonal systems with levonorgestrel), which creates a mechanical barrier to the passage of spermatozoa.
Abortifacient action comes into play in the event of occurred fertilization:
- Increased peristalsis of the fallopian tubes, causing the blastocyst to enter the uterine cavity too quickly, when the endometrium is not yet ready for implantation.
- The foreign body causes local aseptic inflammation of the endometrium. This triggers enzymatic disorders that prevent the attachment of the fertilized egg (the addition of copper enhances this effect).
- Increased synthesis of prostaglandins, leading to enhanced contractility of the uterus itself.
Briefly: answers to topical questions
What are the absolute contraindications to intrauterine device insertion?
Absolute contraindications to intrauterine device insertion are pregnancy, inflammatory and oncological diseases of the genital organs.
These include:
- Pregnancy is an absolute contraindication to contraceptive insertion.
- Acute or subacute pelvic inflammatory diseases — the presence of an active inflammatory process.
- Chronic pelvic inflammatory diseases — in the presence of frequent exacerbations.
- Malignant neoplasms — cancer of the cervix and uterine body.
What complications can occur with the use of intrauterine contraception?
With the use of intrauterine contraception, pain syndrome, uterine bleeding, inflammatory diseases of the internal genital organs, and partial uterine perforation may occur.
The following complications are distinguished:
- Partial uterine perforation — often asymptomatic and diagnosed upon an unsuccessful attempt to remove the IUD.
- Pain syndrome — constant intense pain may be a sign of a mismatch between the IUD size and the uterine cavity, while cramping lower abdominal pain with spotting is a sign of expulsion.
- Inflammatory diseases of the internal genital organs — can be severe and cause pronounced destructive changes in the uterus and appendages.
- Uterine bleeding — more commonly menorrhagia, less commonly metrorrhagia; increased blood loss volume can lead to the development of iron deficiency anemia.
What groups are hormonal contraceptives divided into?
Hormonal contraceptives are divided into agents for scheduled and emergency contraception.
Among scheduled methods, the following are distinguished:
- Combined oral contraceptives — micro-dose, low-dose, and triphasic preparations.
- Progestogen-only oral contraception — so-called mini-pills.
- Prolonged progestogen contraception — injections and implants.
For emergency hormonal contraception, five groups of drugs are used:
- Estrogens;
- Combined estrogen-progestin medications;
- Progestogens;
- Danazol;
- Mifepristone.
Which methods belong to natural (biological) contraception?
Natural methods of contraception include approaches based on calculating the fertile period and abstaining from sexual intercourse during the days close to ovulation.
This group includes:
- Ogino-Knaus calendar (rhythm) method — calculation of the average timing of ovulation and the lifespan of spermatozoa and the oocyte.
- Temperature method — determination of ovulation by changes in rectal (basal) temperature.
These methods have low efficacy (Pearl index ranges from 6 to 40) and require constant self-monitoring.
To memorize the five main groups of contraceptives, use the mnemonic: "All Brilliant Botanists Eat Persimmons" (Intrauterine, Hormonal, Barrier, Natural, Surgical).
Class and exam questions
How is the efficacy of any contraceptive method evaluated?
The Pearl index is used for this purpose. It shows how many women out of a hundred became pregnant within one year of using the evaluated method.
What is the difference between inert and medicated IUDs?
Inert ones consist solely of plastic and are no longer used per WHO recommendations. Medicated ones contain active additives (copper, silver, or hormones), which increases their reliability and reduces the number of adverse reactions.
How does a hormonal intrauterine system work?
In addition to the standard foreign-body effect, it releases levonorgestrel daily. This leads to thickening of the cervical mucus, creating a mechanical barrier to spermatozoa.
What else to study on this topic
- Specifics of using copper-bearing intrauterine contraceptives.
- Therapeutic effects of hormonal contraceptives in gynecology.
- Mechanisms of aseptic inflammation development upon IUD insertion.
- Historical evolution of intrauterine devices from antiquity to the present day.
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