Contraception is an important component of family planning and involves the use of scientific methods to temporarily or permanently prevent pregnancy in women. Contraceptive methods primarily act by regulating three critical processes in reproduction: (1) inhibiting the production of sperm or eggs, (2) preventing the meeting of sperm and eggs, and (3) creating a uterine environment that is unfavorable for sperm capacitation and survival or unsuitable for implantation and development of a fertilized egg. An ideal contraceptive method is one that is safe, effective, simple, practical, economical, has no adverse effects on physiological or sexual functions, and is acceptable and sustainable for both partners. Common contraceptive methods for women include intrauterine device (IUD) contraception, hormonal contraception, barrier contraception, and female sterilization, whereas male methods include condoms and male sterilization.
Intrauterine Device (IUD) Contraception
The intrauterine device (IUD) is a safe, effective, simple, economical, and reversible contraceptive tool that is a commonly used method for women of reproductive age. The typical usage duration ranges from 5 to 10 years.
Types of IUDs
Inert IUDs
Inert IUDs are the first-generation IUDs, commonly made of polyethylene plastic (e.g., Lippes loop IUDs) or stainless steel (e.g., metallic single-ring IUDs). Due to high expulsion and pregnancy rates while in place, the metallic single-ring IUD is no longer produced or used.
Active IUDs
Copper-Containing Active IUDs
These IUDs continuously release biologically active copper ions (Cu2+) into the uterine cavity, offering strong contraceptive effects. Some copper IUDs also contain indomethacin, which reduces heavy menstrual bleeding and dysmenorrhea caused by IUD use. Copper IUDs are available in various shapes, such as T-shaped, V-shaped, and uterine-shaped designs, with different surface areas for copper. Contraceptive effectiveness increases with the copper surface area. Common side effects include changes in menstrual patterns, such as heavier flow, prolonged periods, or irregular bleeding. Popular types of copper IUDs include T-shaped, V-shaped, uterine-shaped, or frameless copper IUDs.
Hormone-Releasing IUDs
The levonorgestrel-releasing intrauterine system (LNG-IUS) is the most widely used hormone-containing IUD in clinical practice. It consists of a polyethylene T-shaped frame with a reservoir storing synthetic levonorgestrel, covered by a membrane made of polymethylsiloxane. There are two common formulations: one containing 52 mg of levonorgestrel, releasing 20 μg daily with a 5-year duration, and a smaller version containing 13.5 mg of levonorgestrel, releasing 8–12 μg daily with a 3-year duration. The smaller version is particularly suitable for young women who have not given birth. Common side effects include menstrual changes such as spotting, reduced flow, or even amenorrhea, which typically resolve after the device is removed.
Mechanisms of Action
The intrauterine device prevents pregnancy through multiple mechanisms.
Interference with Implantation
Foreign body stimulation triggers uterine endometrial damage and chronic inflammatory responses, along with the production of prostaglandins that alter tubal motility, disrupting synchronization between embryo transport and endometrial development, thereby preventing implantation. This is the primary mechanism of action.
Uterine compression leads to localized ischemia and phagocytic cell activation, enhancing plasminogen fibrinolysis and resulting in blastocyst disintegration and absorption.
Copper ions disrupt zinc-dependent enzyme systems such as alkaline phosphatase and carbonic anhydrase, thereby impeding implantation and embryonic development. They also interfere with glycogen metabolism, estrogen uptake, and DNA synthesis, disrupting the metabolic activities of endometrial cells and impeding blastocyst growth.
Toxic Effects on Sperm and Embryos
Copper ions exhibit toxic effects on sperm, causing separation of the sperm head and tail, thereby preventing capacitation.
Inflammation induced by the IUD creates a local environment toxic to embryos, fosters the proliferation of macrophages on the uterine lining, hinders implantation, and impairs both sperm function and embryonic development.
Mechanisms of LNG-IUS
Local progestin effects lead to glandular atrophy in the endometrium, stromal decidualization, and the infiltration of inflammatory cells in the stroma, creating an environment unsuitable for implantation.
Alterations in cervical mucus consistency render it viscous, making it difficult for sperm to penetrate.
Changes in the intrauterine and tubal environment suppress sperm function and inhibit fertilization.
In some women, ovulation may be partially inhibited.
Intrauterine Device (IUD) Placement Procedure
Indications
Women of reproductive age requiring long-term contraception without contraindications are candidates for IUD placement.
Contraindications
These include:
- Pregnancy or suspected pregnancy.
- Acute inflammation of the reproductive tract.
- Tumors of the reproductive organs.
- Congenital abnormalities of the reproductive organs, such as a septate uterus or double uterus.
- Uterine prolapse.
- Severe systemic diseases.
- Uterine cavity depth of less than 5.5 cm or more than 9.0 cm (except in cases of full-term delivery, late-term induced abortion, or placement of frameless copper IUDs).
- Recent menstrual irregularities or unexplained vaginal bleeding within the past 3 months.
- A history of copper allergy (copper IUDs are not suitable in this case).
- Heavy bleeding after surgical abortion with suspected retained pregnancy tissue or infection.
- Uterine atony with bleeding or potential infection following mid-trimester induced abortion, childbirth, or cesarean section with placental delivery.
Timing of Placement
Copper-containing IUDs are usually placed 3 to 7 days after menstruation ends.
LNG-IUS devices are placed within 7 days from the start of menstruation.
Placement can occur immediately postpartum, including after cesarean delivery, provided the healthcare provider has received specialized training.
For postpartum placement, the procedure may also be performed 42 days after delivery, provided lochia has ceased, the perineal wound has healed, and the uterus has returned to normal.
Placement should exclude the possibility of early pregnancy during lactation.
Placement may occur after recovery from natural or medically induced abortion.
Suction curettage for pregnancies less than 10 weeks gestation can include immediate IUD placement.
Placement is also an option within 5 days after intercourse for emergency contraception.
Placement Procedure
Bimanual examination determines the size, position, and condition of the uterus and adnexa. The external genitalia and vaginal area undergo routine disinfection, and sterile drapes are prepared. A speculum is introduced to expose the cervix, which is then disinfected along with the cervical canal. A tenaculum is used to clamp the anterior lip of the cervix, and a uterine probe measures uterine cavity depth along its axis. The IUD is advanced into the uterine cavity using a placement instrument, ensuring the upper edge of the IUD reaches the uterine fundus, after which the instrument is removed. For IUDs equipped with retrieval threads, the threads are trimmed to 2 cm from the external cervical os. The procedure concludes with the removal of the tenaculum and speculum once no bleeding is observed.
Postoperative Care and Follow-Up
Rest for 3 days post-procedure, avoiding heavy physical labor for one week and abstaining from sexual activity and bathing for two weeks are required. External genital hygiene is maintained.
Scheduled follow-ups take place in the first year at 1, 3, 6, and 12 months after placement, and then annually as long as the device is in use. Additional visits are conducted as needed for special circumstances. Follow-up monitors IUD position within the uterine cavity, and any issues are addressed promptly to ensure contraceptive effectiveness.
Side Effects of Intrauterine Devices
Irregular vaginal bleeding is the most common side effect following IUD placement, manifesting as heavier menstrual flow, prolonged periods, or light spotting. These issues typically resolve within 3 to 6 months without intervention. A small percentage of women may experience increased vaginal discharge or lower abdominal discomfort after IUD placement, which should be evaluated and treated symptomatically as needed.
Complications Associated with IUD Placement
IUD Displacement
Causes include unintended uterine perforation during the procedure, where improper manipulation directly places the IUD outside the uterine cavity, or gradual displacement due to uterine contractions when the IUD is too large, rigid, or placed in soft and thin uterine walls. Displacement is confirmed via imaging, and laparoscopic or open surgery may be required to retrieve the IUD.
IUD Embedding or Fracture
Damage to the uterine wall during insertion or prolonged IUD retention may lead to partial embedding in the myometrium or device fracture. Removal should be performed promptly, under ultrasound or hysteroscopic guidance if necessary.
IUD Migration or Expulsion
Causes include improper placement, with the IUD failing to reach the uterine fundus, or mismatch between IUD size and uterine cavity shape and dimensions. These issues are also associated with heavy menstrual bleeding, excessive cervical dilation, or uterine hypersensitivity and commonly occur within the first year of placement.
Pregnancy with an IUD
Pregnancy with an IUD in place is often associated with IUD migration, expulsion, or displacement. Pregnancy termination and simultaneous IUD removal are advised upon confirmation.
Intrauterine Device Removal Procedure
Indications
Physiological:
- Individuals planning to conceive or no longer requiring contraception due to cessation of sexual activity.
- Expired IUD requiring replacement.
- Within one year of menopause for perimenopausal women.
- Preference for alternative contraceptive methods or sterilization.
Pathological:
- Complications or side effects unresponsive to treatment.
- Pregnancy with an IUD, including intrauterine or ectopic pregnancy.
Contraindications
These include:
- Active reproductive tract infections, where IUD removal should be deferred until after anti-infective treatment.
- Poor general health or acute medical conditions, during which removal is postponed until stabilization.
Timing for Removal
Ideally, removal is performed 3 to 7 days after menstruation ends.
Early pregnancy with an IUD in place may coincide with surgical abortion and IUD removal.
Ectopic pregnancy with an IUD in place may require removal before, during, or after ectopic treatment.
Unexplained uterine bleeding allows for removal at any time, during which diagnostic curettage may be performed and endometrial tissue submitted for pathology to exclude endometrial disease.
Removal Procedure
Routine sterilization is performed. For IUDs with retrieval threads, a hemostat gently pulls the threads to retrieve the device. For IUDs without threads, removal is conducted in an operating room using specialized tools such as retrieval hooks or forceps. For difficult cases, removal may be guided by ultrasound or performed under hysteroscopic visualization.
Precautions
Ultrasound or X-ray imaging should confirm the IUD's location within the uterine cavity and identify its type before removal.
Careful manipulation is necessary when using retrieval hooks to avoid uterine wall damage.
The retrieved IUD should be inspected for completeness. Fragments or incomplete removals require further imaging and corresponding intervention.
Post-removal, alternative contraception, or sterilization plans should be established.
In postmenopausal women, cervical condition assessment, cervical preparation, and anesthesia may be required prior to IUD removal.
Hormonal Contraception
Hormonal contraception refers to an effective method of contraception for women that involves the use of steroid hormones. The active components of hormonal contraceptives are estrogen and progestin.
Mechanisms of Action of Steroid Hormonal Contraceptives
Inhibition of Ovulation
Progestins in contraceptives inhibit the hypothalamic release of GnRH via negative feedback, which in turn suppresses pituitary secretion of FSH and LH, interfering with follicular development. Progestins also directly affect the pituitary's response to GnRH, preventing the pre-ovulatory LH surge and thereby suppressing ovulation.
Alteration of Cervical Mucus Properties
Progestins reduce the quantity of cervical mucus, increase its viscosity, and lower its stretchability, which impedes sperm penetration. This alteration of cervical mucus may be one of the primary mechanisms of action in progestin-only formulations.
Changes in Endometrial Structure and Function
Normal physiological changes in the endometrium are essential for embryo implantation. Steroid hormones in contraceptives suppress the proliferative changes in the endometrium, causing an asynchrony between endometrial development and embryonic requirements, rendering the lining unsuitable for implantation of a fertilized egg.
Disruption of Fallopian Tube Function
Under the influence of estrogen and progestin, functional changes occur in the epithelial cilia, segmental muscular activity, and fluid secretion within the fallopian tubes. These disruptions interfere with the normal transport of the fertilized egg through the fallopian tube.
Types of Steroid Hormonal Contraceptives
Steroid hormonal contraceptives are categorized by duration of action into short-acting, long-acting, rapid-acting, and slow-release types. They can also be classified based on the mode of administration, including oral, injectable, transdermal, vaginal, and intrauterine routes.
Oral Contraceptives (OC)
Combined Short-Acting Oral Contraceptives
These formulations combine estrogen and progestin. The estrogen component is primarily ethinyl estradiol, while the progestin components vary to create different formulations. Over time, the ethinyl estradiol content in combined oral contraceptives has been reduced from 35 μg to 20 μg, and the progestin structures have become more similar to natural progesterone, enhancing contraceptive efficacy and reducing side effects.
Dosage and Use
Combined short-acting oral contraceptives are commonly initiated on the first day of the menstrual cycle. The number of active pills varies with the formulation. For a 21-pill pack, pills are taken daily for 21 days, followed by a 7-day break before starting the next cycle. For a 24+4 pack, 24 active pills are followed by 4 placebo pills, with no break before transitioning to the next cycle. In cases of missed pills, it is important to take the missed dose as soon as possible and be aware of the potential for pregnancy. Detailed instructions for use and missed doses are provided in the medication's prescribing information. When used correctly, this method achieves high contraceptive efficacy, but effectiveness declines with missed doses.
Combined Long-Acting Oral Contraceptives
These are composed of long-acting estrogens and synthetic progestins. A single dose provides contraception for one month. The estrogen component is ethinylestradiol cyclopentyl ether (CEE), which is absorbed through the gastrointestinal tract and stored in adipose tissue, from where it is slowly released to exert prolonged contraceptive effects. Progestins induce the transformation of the endometrium to the secretory phase, resulting in withdrawal bleeding. Due to their high hormone content and associated side effects, such as early pregnancy-like symptoms and menstrual irregularities, long-acting oral contraceptives are rarely used in clinical practice.
Injectable Contraceptives (IC)
Injectable contraceptives consist of either progestin-only formulations or combined estrogen-progestin formulations. They are particularly suitable for women experiencing significant gastrointestinal side effects from oral contraceptives. A single intramuscular injection of a combined estrogen-progestin preparation provides contraception for one month. The initial dosage requires injections on the 5th and 12th days of the menstrual cycle, followed by subsequent injections on the 10th to 12th day of each cycle. Typically, menstruation occurs 12 to 16 days after injection.
Progestin-only injectables include depot medroxyprogesterone acetate (DMPA), administered once every 3 months, and norethisterone enanthate, administered once every 2 months intramuscularly. Common side effects include menstrual irregularities, spotting, and amenorrhea. Progestin-only formulations have minimal impact on breast milk volume and quality, making them particularly suitable for breastfeeding women.
Slow-Release Contraceptives
Slow-release systems use polymers with controlled-release capabilities to deliver sustained, low-dose steroid hormones for long-term contraception. These systems include subdermal implants, vaginal rings, contraceptive patches, and hormone-containing intrauterine devices.
Subdermal Implants
Subdermal implants are contraceptive systems containing progestins. Levonorgestrel subdermal implants are available in two types: Type I contains six silicone rods, each containing 36 mg of levonorgestrel (totaling 216 mg), providing contraception for 5 to 7 years. Type II contains two silicone rods, each containing 75 mg of levonorgestrel (totaling 150 mg), with a duration of 3 to 5 years. Etonogestrel single-rod implants contain 68 mg of etonogestrel, are simple to insert, have fewer side effects, and provide contraception for 3 years.
Administration: Subdermal implants can be placed within the first 7 days of the menstrual cycle. The rods are inserted subcutaneously into the inner side of the upper left arm in a fan-shaped arrangement. These implants begin to take effect within 24 hours of placement, releasing approximately 30 μg of hormone daily. As a progestin-only method, the most common side effects are spotting or irregular bleeding, which tend to improve over time. Rarely, functional ovarian cysts, mood changes, or headaches may occur.
Vaginal Contraceptive Rings
These rings are composed of silicone or flexible plastic materials containing hormones that are released in small daily doses. The hormones are absorbed through the vaginal wall into the bloodstream to achieve a contraceptive effect. Etonogestrel and ethinyl estradiol-containing vaginal rings measure 54 mm in diameter and 4 mm in cross-sectional thickness, with 11.7 mg of etonogestrel and 2.7 mg of ethinyl estradiol. They are inserted on the first day of menstruation, left in place for 3 weeks, and removed for 1 week before the next ring is inserted.
Contraceptive Patches
These patches are loaded with contraceptive hormones that are absorbed through the skin. A single patch is worn for one week, with a total of three patches used in a 4-week cycle. Hormones are released in controlled doses daily, providing effective contraception.
Contraindications and Cautionary Use of Steroid Hormonal Contraceptives
Contraindications and cautionary conditions for the use of steroid hormonal contraceptives include:
- Severe cardiovascular conditions and thrombotic diseases, such as hypertension, coronary artery disease, and venous thrombosis.
- Acute or chronic hepatitis or nephritis.
- Hormone-dependent tumors or precancerous lesions.
- Endocrine diseases, such as diabetes mellitus and hyperthyroidism, are considered relative contraindications.
- During breastfeeding, contraceptives containing estrogen are not recommended.
- Women over the age of 35 who smoke.
- Patients with mental health conditions.
- Severe or recurrent migraines.
Side Effects of Steroid Hormonal Contraceptives and Management
Early Pregnancy-like Reactions
Approximately 10% of women may experience symptoms during the initial period of use, including reduced appetite, nausea, vomiting, fatigue, dizziness, and breast tenderness, which resemble early pregnancy. These typically resolve naturally after a few cycles of continued use without the need for special treatment. For severe symptoms, alternative formulations or other contraceptive methods may be considered.
Changes in Bleeding Patterns
Changes include irregular vaginal bleeding and amenorrhea. Vaginal bleeding during use is often referred to as breakthrough bleeding. Most cases occur after missed doses of contraceptive pills, although they may also occur without missed doses. Mild spotting typically decreases and stops over time with continued use and does not require intervention. For heavier bleeding, supplemental estrogen may be taken nightly in conjunction with the contraceptive until cessation of symptoms. If bleeding resembles menstrual flow or occurs near the expected period, use may be paused and counted as a menstrual cycle. The contraceptive can then be restarted in the next cycle or replaced with an alternative option. Approximately 1–2% of women may experience amenorrhea after using oral contraceptives. If menstruation does not resume after discontinuation, pregnancy should be ruled out. Following a 7-day discontinuation, use may continue, but if amenorrhea persists for three months, discontinuation and further observation may be necessary.
Weight and Skin Changes
Earlier contraceptive formulations with strong androgenic activity occasionally caused increased appetite, enhanced anabolic effects, and weight gain in some women, as well as mild hyperpigmentation on the face in rare cases. With newer formulations, androgenic activity is significantly reduced, progestin activity is enhanced, and doses are smaller, leading to fewer side effects. They may even alleviate skin conditions such as acne and excessive hair growth. Drospirenone/ethinyl estradiol tablets contain drospirenone, which has anti-mineralocorticoid effects, reducing water and sodium retention caused by estrogen.
Other Effects
Some women may experience headaches, double vision, or other symptoms. Management involves symptomatic treatment, and further examination may be required if symptoms persist, possibly necessitating discontinuation.
Effects of Steroid Hormonal Contraceptives on the Body
Effects on Metabolism
The impact of long-term use of steroid hormonal contraceptives on glucose metabolism depends on the composition and dosage of estrogen and progestin in the contraceptive. A small number of users may experience changes in glucose tolerance due to effects on pancreatic islet function, but symptoms typically resolve after discontinuation. Regarding lipid metabolism, estrogen reduces low-density lipoprotein (LDL) levels while increasing high-density lipoprotein (HDL) levels, and it can also raise triglyceride levels. Progestins may counteract estrogen-induced increases in triglycerides but may reduce HDL levels. Women with cardiovascular conditions and high-risk factors (e.g., age >40 years, long-term smoking, obesity, or hypertension) are not suitable candidates for long-term use of steroid hormonal contraceptives. Effects on protein metabolism are minimal and lack clinical significance.
Effects on the Cardiovascular System
Long-term use of steroid hormonal contraceptives may influence the cardiovascular system, increasing the risk of conditions such as stroke and myocardial infarction due to effects on lipid metabolism. However, modern low-dose steroid hormonal contraceptives significantly lower the risk of cardiovascular complications, especially in women under 35 years old who do not smoke, have no history of hypertension, and do not experience elevated blood pressure during use.
Effects on Coagulation
Oral estrogens can increase coagulation factors, and high doses of estrogen elevate the risk of thrombotic disorders. Current short-acting contraceptives contain 20–35 μg of ethinyl estradiol, categorized as low-dose steroids, which do not increase the incidence of thrombotic diseases. For individuals at risk of thrombosis, non-oral options such as subdermal implants, vaginal contraceptive rings, or contraceptive patches are recommended to reduce thrombotic risk.
Effects on Tumors
The progestin component in combined oral contraceptives has a protective effect on the endometrium, reducing the risk of endometrial cancer. Long-term use of combined oral contraceptives also lowers the incidence of ovarian cancer. However, whether long-term use of steroid hormonal contraceptives increases the risk of breast cancer remains a subject of ongoing research and debate.
Effects on Offspring
Evidence suggests that pregnancy following the discontinuation of combined short-acting oral contraceptives does not increase the incidence of fetal abnormalities. Due to the short half-life of hormones in combined short-acting oral contraceptives, conception can occur immediately after discontinuation without impacting the growth and development of the offspring. For long-acting contraceptives, the difference in hormone composition and dosage compared to short-acting options necessitates a safer window of six months between discontinuation and conception.
Other Effects
Combined steroid hormonal contraceptives provide additional non-contraceptive benefits, including regulation of the menstrual cycle, reduction of menstrual volume, relief of dysmenorrhea and premenstrual syndrome, and prevention of endometrial hyperplasia-related disorders.
Other Contraceptive Methods
Other contraceptive methods include emergency contraception, barrier contraception, and natural family planning.
Emergency Contraception
Emergency contraception refers to a remedial method of contraception used by women within hours or days after unprotected sexual intercourse or contraceptive failure to prevent unintended pregnancy. This includes the insertion of a copper-containing intrauterine device (IUD) and the use of oral emergency contraceptive pills.
Indications
These include:
- Contraceptive failure, such as condom rupture or slippage, failure to withdraw before ejaculation, miscalculation of the safe period, missed doses of short-acting oral contraceptives, or expulsion of an intrauterine contraceptive device.
- Sexual intercourse without any contraceptive measures.
- Sexual violence.
Methods
Intrauterine Device
A copper-containing intrauterine device can be used for emergency contraception. It is particularly suitable for individuals who require long-term contraception, meet the criteria for IUD placement, or have contraindications to hormonal contraceptives. Insertion within 5 days (120 hours) of unprotected sexual intercourse has a failure rate of less than 1%.
Types and Usage of Emergency Contraceptive Pills
These include:
- Progestin-Only Preparations: Levonorgestrel tablets that contain 0.75 mg of levonorgestrel. One tablet is taken within 72 hours of unprotected intercourse, followed by another tablet 12 hours later.
- Anti-Progestin Preparations: Mifepristone (10 mg), which has been used as an emergency contraceptive. A single dose taken within 72 hours of unprotected intercourse is effective.
- Combined Estrogen-Progestin Preparations: The combined preparations available typically include levonorgestrel (150 μg) and ethinyl estradiol (30 μg). Four tablets are taken within 72 hours of unprotected intercourse, followed by an additional four tablets 12 hours later.
Side Effects
After taking emergency contraception, some individuals may experience nausea, vomiting, irregular vaginal bleeding, or menstrual disturbances. These effects generally do not require treatment. If menstruation is delayed by more than one week, pregnancy should be ruled out. It is important to note that emergency contraception is only effective for one instance of unprotected intercourse and is less effective than routine contraceptive methods.
Barrier Contraception
Barrier contraception involves using physical or chemical barriers to block sperm from reaching the uterus or to inactivate sperm within the vagina.
Male Condoms
Male condoms prevent sperm from entering the vagina by acting as a physical barrier. They are made from high-quality, thin latex in a tubular shape with a small pouch at the tip for semen collection, typically with a capacity of 1.8 ml. Condoms are available in four sizes: 29 mm, 31 mm, 33 mm, and 35 mm. Before use, they should be tested for leaks by inflating them, and air should be removed from the tip before application. Condoms should be removed together with the penis while it is still erect, holding the base of the condom to prevent leakage. The correct size should be selected to avoid improper fit. Each condom is for single use only, and they should be used consistently during every sexual encounter. Proper use results in a contraceptive efficacy of 93–95%. Male condoms also provide protection against sexually transmitted infections (STIs), making them particularly suitable for young and sexually active individuals.
Female Condoms
Female condoms provide both contraceptive benefits and protection against STIs.
Spermicides
Spermicides are chemical contraceptives inserted into the vagina before intercourse that inactivate sperm. Common formulations include suppositories, tablets, gels, creams, and contraceptive films, typically made with the active ingredient nonoxynol-9 combined with a base material. Nonoxynol-9 disrupts the acrosomal membrane of sperms, rendering them inactive. The base material ensures even distribution over the cervical opening, enhancing the spermicide's effectiveness. Some considerations include:
- Application is required before each act of intercourse.
- Suppositories, tablets, and films need to dissolve in the vagina for 5–10 minutes before intercourse. If no intercourse occurs within 30 minutes after insertion, another dose is necessary.
- For women in peri-menopause with reduced vaginal secretions, gel-based formulations are recommended as they dissolve more effectively than other forms.
- Misuse or inconsistent application can result in a failure rate exceeding 20%.
Natural Family Planning (NFP)
Natural family planning involves leveraging knowledge of the menstrual cycle to determine the "safe period" for contraception. This method is based on estimating ovulation dates and abstaining from intercourse during the fertile window to prevent conception. Due to its high failure rate, natural family planning is not highly reliable and is not recommended for widespread use.
Calendar Method
This method is suitable for women with regular menstrual cycles. Ovulation typically occurs approximately 14 days before the next menstrual period. Based on this, the 4–5 days surrounding ovulation are considered the fertile period, while the remaining time is considered the safe period.
Basal Body Temperature (BBT) and Cervical Mucus Methods
These methods involve observing basal body temperature or cervical mucus to predict ovulation. However, the relationship between basal body temperature changes and ovulation is not consistent, and proper assessment of cervical mucus requires prior training.
Lactational Amenorrhea Method
This natural contraceptive method applies to the first six months postpartum in women who are exclusively or predominantly breastfeeding and have not resumed menstruation.
Other Contraceptive Methods
Other methods under research include the use of luteinizing hormone-releasing hormone (LHRH) analog contraceptives, immunocontraception techniques, and antifertility vaccines.