Contraception: most used birth control methods
For the woman and the couple, contraception is a fundamental choice to live sexuality in a conscious and responsible way.
However, it is important to keep in mind that the choice of the birth control method depends on several social, health, economic and religious features of the couple. I always recommend to my patients who are having a gynecological examination in Florence to both ask themselves and ask me specific questions, to be able to choose the most suitable contraceptive for the needs of each of them; let’s see some useful questions:
How effective is a particular contraceptive?
The effectiveness of a contraceptive is indicated as the number of unintended pregnancies in 100 women using a particular method for one year (Pearl index). Values < 1 represent a good index of Pearl, as happens with the pill and with condoms when used correctly.
In addition to pregnancy, what am I protected from?
Not all birth control methods also offer protection against sexually transmitted diseases: the best efficacy against STDs is offered by condoms, while the pill and the intrauterine device offer no health protection.
What are the side effects of the different contraception methods?
Some contraceptives (e.g. combined contraceptives, or IUD) have adverse effects, sometimes even serious, and they have certain drawbacks in people at risk. Barrier methods, such as condoms, can only have allergic reactions as a side effect, while intrauterine devices (coil) determine a minimal increase in the risk of infections, ectopic pregnancy and pelvic pain. There are however the latest generation of small IUDs, which limit or cancel out a good part of these side effects, by acting on one side as intrauterine device and on the other as a hormonal contraceptive, because they release directly and locally small amounts of a hormone.
How does a birth control method interfere with the relationship?
The couple should be able to deal easily with the method, which should interfere as little as possible with the spontaneity of the sexual intercourse. Unlike condoms and natural methods, the pill and the IUD do not interfere with the spontaneity of the relationship.
What are the other benefits of contraceptives?
Some methods may have beneficial effects on women’s health, such as oral contraceptives, which reduce the risk of ovarian and endometrial cancer if taken for a certain time.
How much do they cost?
Some methods are very inexpensive, if not free (see natural methods), the pill has a cost ranging from about 7 to 15 euros per month and the average cost of condoms is slightly less than 50 euro cents each.
Contraception methods are distinguished in:
- natural methods
- barrier methods
- hormonal methods
1. Natural methods:
The natural regulation of fertility is based on abstention from sexual relations during the fertile period of the female cycle, which is identified with specific techniques. These methods include:
- rhythm or calendar method
- BBT measurement
- evaluation of cervical mucus
- symptothermal method
- hormonal method of measurement by household kits
The rhythm method (also known as Ogino Knauss) is based on the calculation of the fertile days and assesses the ovulation to be likely to happen on the 14th day before the future menstruation, which is assumed by averaging the previous 6 cycles. This method has a high failure rate (10%) especially in subjects who have hormonal cycles exceeding 32 or shorter than 26 days.
The measurement of basal body temperature should be done with a special thermometer every morning before getting out of bed and written down in a special chart or on your phone using a tracking app. At about half of the cycle the temperature increases of about one degree due to ovulation. Since the average survival of sperm in the female genital tract is 5 days and the egg survival time is about 24 hours, the days after the rise of the temperature, i.e. after ovulation, are considered non-fertile days.
The Billings method or cervical mucus method involves the observation of cervical mucus, that around ovulation becomes abundant and more fluid. The fertile period is the one that includes the first day from the onset of this feature up to 4 days from the end of it.
Household kits have been developed to identify the fertile days using several variables: the rovumeter is a small device capable of sucking the vaginal mucus at the level of the posterior fornix and to evaluate its volume. Indeed, the volume of cervical-vaginal secretions varies significantly during the fertile phase, reaching the highest level 48-24 hours before ovulation. Another device proposed by Freundl is capable of measuring the electrical resistance of saliva and vaginal secretions and their variations during the menstrual cycle, thus signaling the fertile periods. Recently a device called Persona® has been proposed, it measures urinary levels of LH and estrone-3-glucuronide, a metabolic of estradiol. The detection lasts a few seconds and is performed by means of a stick which must be kept in the flow of the first urine of the day, and is then analyzed by the device, which is capable of storing the hormonal values recorded, the length of each cycle and the first day of fertile period. A red or green light communicates the data processing results (red = fertile, green = infertile). The Pearl index of this method is about 2.
The sympto-thermal method combines the Ogino Knaus method to that of basal temperature and cervical mucus achieving a failure rate of 2% (if done correctly).
The natural birth control methods have many advantages because they don’t have adverse effects, educate adolescents to a correct interpretation of the value of sexuality, are openly supported by the Catholic church and are inexpensive. On the other hand, however, they are hindered by a variable efficacy that is much lower than the other methods; above all they rely on a constant commitment of both partners, and periods of abstinence can determine psychological stress. In addition, they require a training period and have no protective effect against sexually transmitted diseases.
2. Barrier methods:
- male condom
- IUD (Intrauterine Device)
The male condom is the most widespread mean of contraception and the safest for the prevention of sexually transmitted diseases, with a failure rate mainly due to breakage associated with incorrect use. Some important steps can prevent this complication, such as usage before expiration date, proper storage, i.e. away from heat sources, and a correct application according to the instructions. Also it should be noted that the use of vaginal creams, both therapeutic and lubricants, can damage the surface of the condom and increase the risk of breakage. In case of allergy to latex, there exist specific condoms free of this substance. The condom has the advantage of being easy to use, requires no medical prescription, has a lower cost per single use, but high if used for a long time, and is the best protection for sexually transmitted diseases. On the other hand, it has the drawback of possible breakage, it entrusts the control of contraception to the male partner and interferes with the spontaneity of sexual intercourse, finally, Roman Catholic Church was opposed to its use, especially in the past.
The diaphragm is an element, usually made of latex, which is to be introduced into the vagina to cover the cervix. On the inner surface it is covered with spermicidal cream for extra protection. It can be placed some time before the start of sexual intercourse and should be removed 8 hours after the intercourse itself. It is an inexpensive method, but has a high failure rate, and many of the failures are due to incorrect insertion. Also exerting pressure on the urethra increases the risk of urinary tract infections, and does not protect against sexually transmitted diseases.
Spermicides are substances in the form of suppositories, creams, jellies or sponges, readily available and not subject to medical prescription. They should be introduced deeply in vagina shortly before intercourse and are effective for about one hour. They have the advantage of providing a certain vaginal lubrication, useful in the period of perimenopause, and of being inexpensive and easy to use. On the other hand, the Pearl index is high (10-20); they can cause local allergic or irritant reactions, do not protect against sexually transmitted diseases and can be associated with other barrier methods.
The intrauterine device (IUD) is placed by the gynecologist at the level of the fundus of the uterus. It is usually used in women who have already given birth. It creates a situation of local sterile inflammation that hinders sperm function.
Hormonal IUD which releases Levonorgestrel is also available, levonorgestrel is a derivative of progesterone that enhances the effects on sperm. Among the advantages of the IUD there is the independence from sexual intercourse, and its low cost since it can be kept in place for up to 3-5 years. It is one of the safest methods of contraception with 0.8% of Pearl index for the nonhormonal IUD and 0.1% for the hormonal IUD. The most common side effects are abdominal colic and menorrhagia, limited to the first months of use, while rarer effects result in an increased risk of ectopic pregnancy, pelvic inflammation and infection (endometritis or salpingitis) and, in extreme situations, the uterine perforation.
3. Hormonal methods:
Hormonal contraceptive methods involve the assumption, with different timing and routes of administration, of estrogen and progesterone or only progesterone. The mechanism of action depends on the block of ovulation through inhibition of gonadotropin secretion, the modification of the endometrium which makes it unfavorable to the implant, the influence on cervical mucus which makes it more thick and therefore an obstacle to the passage of sperm.
I contraccettivi orali sono costituiti da confezioni contenenti 21 o 28 pillole. Nei preparati a 21 pillole la donna assume una pillola al giorno per 21 giorni iniziando dal primo giorno del ciclo (primo giorno di mestruazione) segue una pausa di 7 giorni duranti i quali compaiono le mestruazioni. Le confezioni da 28 pillole sono costituite da 21 pillole efficaci e 7 pillole senza alcun principio attivo per permettere un’assunzione continuativa senza pausa. La composizione delle pillole può essere uguale in tutte e si parla di contraccettivo monobasico o può variare la percentuale di estrogeni e progesterone e si parla di contraccettivo bifasico o trifasico.
Oral contraceptives consist of packs containing 21 or 28 pills. In compounds of 21 pills a woman takes a pill once a day for 21 days starting from the first day of the cycle (first day of menstrual bleeding), followed by a seven-day break during which menses occur. The packs of 28 pills consist of 21 effective pills and 7 pills without any active ingredients to allow a continuous intake without pause. The composition of the pills can be equal for all and we talk about monobasic contraceptive or can vary in the percentage of estrogen and progesterone, and we talk about biphasic or triphasic contraceptive.
The advantages of oral contraceptives consist of an excellent efficacy with Pearl Index <0.3 in case of proper use, the fact that they aren’t correlated with the sexual act and the rapid reversibility to fertility. They have additional beneficial effects on women’s health: it has been shown that some estrogen and progestogen associations reduce the risk of ovarian and endometrial cancers, and that this reduction persists years after their use; reduce the risk of benign conditions such as ovarian cysts, pelvic inflammatory disease and endometriosis, improve the clinical pictures of acne, hirsutism, endometriosis, dysmenorrhea and premenstrual syndrome, menorrhagia from fibroids, and polycystic ovary syndrome.
The use of oral contraceptives, however, must be under medical supervision because of possible side effects; oral contraceptives are contraindicated in some patients with certain risk factors.
The most common and mild side effects consist of nausea, headache, breast tenderness, weight gain and altered mood and libido. In rarer cases, and in subjects at risk they can cause deep vein thrombosis, cerebral ischemia, occurrence of hepatic adenomas and, very rarely, hepatocellular carcinomas. It is the duty of the physician to perform an adequate personal and family medical history in order to identify certain risk factors for which the administration of oral contraceptives may be contraindicated.
More in detail, the use of hormonal contraceptives is contraindicated in patients with:
- Hypertension, headache, and smokers (> 15 sig / day)
- Personal history of previous brain ischemia, pulmonary embolism, venous thrombosis.
- Hepatitis in active phase or benign or malignant tumors of the liver and gallbladder diseases.
- Inflammatory bowel disease (use of contraceptives leads to a worsening of the disease)
- Breast Cancer
- Positive family history of thromboembolism (in the case it is present it may be useful to explore the clinical picture with specific blood tests)
- There are also special conditions such as epilepsy, obesity etc. for which is required a consultation of more specialists in order to obtain the best result for the patient.
An oral contraceptive containing progestin only may also be prescribed, its action is aimed solely at promoting the thickening cervical mucus, creating an environment unfavorable to the implant on the surface of the endometrium. Because of the absence of estrogen, this pill is indicated for those patients who have contraindications to the use of combined contraceptives.
In addition to the oral mode there are other ways of administration of hormonal contraceptives:
- Injectable contraceptives based on progestin that may be administered on a quarterly basis or on a monthly basis.
- Subcutaneous implants that release a fixed daily amount of hormones.
- Transdermal delivery devices which are applied from the first day of flow and replaced every week for 3 weeks followed by one-week interval.
- Transvaginal delivery devices that are inserted by the fifth day of the cycle into the vagina and left in place for three weeks at the end of which are removed with the appearance of the menstrual flow.