Contraceptives

Definition

Contraception is the prevention of conception by methods other than abstinence. It is used to limit the size or space the family (birth control or family planning).

Ideal Contraception

An ideal contraception should fulfill the following:

• Highly efficient

• Free from unwanted side effects

• Absolute safety

• Independent of intercourse

• Simplicity of use

• Reversible

• Well tolerated

Methods of Contraception (Overview)

Barrier Methods

• Have been the most widely used contraceptive technique throughout recorded history.

• The condom – male and female

• Diaphragms and cervical caps

• Sponge

• Spermicides

Hormonal Methods

Combined preparations:

• Combined oral contraceptive pills

• Combined hormonal patches

• Combined vaginal rings

Progestogen-only preparations:

• Progestogen-only pills (mini pill)

• Injectable contraceptives

• Subdermal implants

Intrauterine Contraception

• Copper intrauterine contraceptive device (IUCD)

• Hormone releasing intrauterine system (LNG-IUS)

Sterilization

• Vasectomy (male sterilization)

• Female sterilization

Natural Family Planning

• Coitus interruptus

• Fertility awareness methods:

  • Billings (cervical mucus)

  • Basal body temperature

  • Calendar (rhythm method)

• Lactational amenorrhoea (LAM)

Efficacy of Contraceptive Methods

• Virtually all methods occasionally fail. Some are much more effective than others.

• Pearl index (failure rate): Expressed as the number of failures per 100 women-years (HWY) – that is, the number of pregnancies occurring if 100 women were to use a method for 1 year.

Failure rates (per 100 women-years):

Perfect use / Typical use

• Combined oral contraceptive pill: 0.1 / 3

• Progestogen-only pill: 1.1 / 9.6

• Depo-Provera: 0.1 / 2

• Implant: 0.05 / 0.05

• Copper-bearing IUD: 0.8 / 3

• Levonorgestrel-releasing IUD: 0.5 / 0.5

• Male condom: 2-5 / 15

• Female diaphragm: 5 / 16

• Female condom: 21 / 21

• Natural family planning: 2-3 / 28

• Vasectomy: 0.02 / 0.15

• Female sterilization: 0.13 / 0.5

• LAM: 2 / (not specified)

• No method: 85

Barrier Methods (Detailed)

The Condom

• Simple

• Effective – 85 to 98% success rate

• No side effects

• Readily available

• Reduces the risk of STIs, HIV, and cervical neoplasia

Diaphragms, Cervical Caps, and The Sponge

• Diaphragms and cervical caps should be used with spermicide.

• Failure rate: 5-16%

• The sponge: Known in the UK and USA.

• Advantage of the sponge: Can be left for 24 hours in the vagina; one size fits all women.

Spermicides

• Available as creams, gels, aerosols, melting suppositories, and foaming tablets.

• Used alone: Failure rate 10-15%

Hormonal Methods (Detailed)

Oral Contraception – Two types:

Combined oral contraceptive pill (COC): Most commonly used (estrogen + progestogen). Examples: Microgynon, Safeplan, oralconF.

Progestogen-only pill (POP / mini pill): Example: Microlut.

Combined Oral Contraceptives (COCs)

Composition: Estrogen (E) and progestin (P)

Types:

• Monophasic pills: Same dose of E/P throughout the course.

• Biphasic pills: Fixed dose of E/P, then more P in the last 14 days.

• Triphasic pills: Variable dose of E/P.

• Sequential pills: Fixed dose of E, no P for first 7 days, then P for 14 days.

• Note: Biphasic, triphasic, and sequential pills are not in common use.

Mechanism of Action:

• Prevents ovulation by inhibiting gonadotrophin secretion (effect on both pituitary and hypothalamic centres).

• Progestin suppresses LH secretion (prevents ovulation).

• Estrogen suppresses FSH secretion (prevents selection and emergence of a dominant follicle).

Efficacy of COC:

• Typical use: 3.0% failure rate during the first year.

• Efficacy decreases significantly when the estrogen component is removed.

Absolute contraindications to COC use:

• Thrombophlebitis, thromboembolic disorders, CVA, coronary occlusion

• Markedly impaired liver function

• Known or suspected breast cancer

• Undiagnosed abnormal vaginal bleeding

• Known or suspected pregnancy

• Smokers over age 35

Relative contraindications to COC use:

• Migraine headaches

• Hypertension

• History of gestational diabetes

• Elective surgery

• Epilepsy

• History of obstructive jaundice in pregnancy

• Sickle cell disease or sickle C disease

• Diabetes mellitus

• Gall bladder disease

Clinical problems associated with COCs:

• Drugs that affect efficacy

• Migraine headaches

• Breakthrough bleeding

• Amenorrhoea

• Weight gain

• Acne (rarely)

Drug interactions:

Effect of other drugs on COC (reduce efficacy):

• Enzyme-inducing drugs: barbiturates, antiepileptics (except sodium valproate and clonazepam), rifampicin, ketoconazole, griseofulvin, ritonavir, nevirapine.

• Some broad-spectrum antibiotics: amoxicillin, tetracycline, doxycycline (impair absorption of ethinyl estradiol).

• Management: Use high-dose preparations (ethinyl estradiol 50µg or more) or add barrier method.

Effect of COCs on other drugs:

• Decreased effectiveness of aspirin, oral anticoagulants, oral hypoglycaemics.

• Increased effectiveness of beta-blockers, corticosteroids, diazepam, aminophylline.

Non-contraceptive benefits of OCs:

Incidental benefits:

• Less endometrial cancer

• Less ovarian cancer

• Fewer ectopic pregnancies

• More regular menses

• Less anaemia

• Less PID

• Less rheumatoid arthritis

• Increased bone density

• Less endometriosis

• Less benign breast disease

• Fewer ovarian cysts

COCs as treatment for:

• Dysfunctional uterine bleeding (DUB)

• Dysmenorrhoea

• Mittelschmerz

• Endometriosis prophylaxis

• Acne and hirsutism

• Hormone therapy for hypothalamic amenorrhoea

• Control of bleeding

• Premenstrual syndrome

Pill taking:

• Effective contraception is present during the first cycle if pills are started no later than the 5th day of the cycle and no pills are missed.

Missed pills protocol:

• 1-2 pills missed: Take the most recent missed pill as soon as remembered. Continue remaining pills daily at usual time. No back-up needed.

• 3 or more pills missed: Take the most recent missed pill as soon as remembered. Continue remaining pills daily. Back-up needed for next 7 days.

• If 3+ pills missed in first week: Consider emergency contraception if she had sex.

• If pills missed in 3rd week: Finish current pack, then start new pack the next day (omit pill-free interval).

Advantages of COCs:

• Simple to use and highly effective

• No special preparation before intercourse

• May relieve irregular periods, cramps, and premenstrual tension

Progestogen-Only Pill (POP / Mini Pill)

• Contains a small dose of progestogen (25% of that in COC). Must be taken daily, continuously.

Mechanism of action:

• Endometrium involutes and becomes hostile to implantation.

• Cervical mucus becomes thick and impermeable.

• Gonadotrophins are not consistently suppressed.

Features:

• No significant metabolic effects (lipids, CHO metabolism, coagulation factors unchanged).

• Immediate return to fertility upon discontinuation.

• Failure rates: 1.1 to 9.6% per 100 women in first year.

Pill taking:

• Start on first day of menses. Back-up method needed for first 7 days.

• Take at the same time each day.

• If more than 3 hours late, use back-up method for 48 hours.

Problems associated with POP:

• Unpredictable effect on ovulation:

  • 40% normal ovulatory cycles

  • 40% short irregular cycles

  • 20% total lack of cycles (irregular bleeding, spotting, amenorrhoea)

• Development of functional cysts

• Levonorgestrel minipill may be associated with acne

Situations with excellent efficacy:

• Lactating women (prolactin-induced suppression of ovulation adds to effect)

• Women over age 40 (reduced fecundity adds to effect)

Implant Contraception

Norplant:

• 6 capsules (34mm long, 2.4mm diameter) containing 36mg crystalline levonorgestrel each. Total 216mg.

• Releases ~80µg levonorgestrel per 24 hours during first 6-12 months.

• Effective life: 5 years.

Mechanism of action:

• Suppresses hypothalamic and pituitary LH surge needed for ovulation.

• Constant progestin thickens cervical mucus.

• Suppresses estradiol-induced cyclic endometrial maturation, causing atrophy.

Disadvantages of Norplant:

• Disruption of bleeding patterns in up to 80% of users.

• Surgical insertion and removal by trained personnel.

• Implants visible under skin.

• No STI/HIV protection.

• Acne.

Absolute contraindications:

• Active thrombophlebitis or thromboembolic phenomena

• Undiagnosed genital bleeding

• Acute liver disease

• Benign or malignant liver tumours

• Known or suspected breast cancer

Implanon:

• Single implant, 4cm long, contains 60mg of 3-keto desogestrel.

• Releases ~60µg per day.

• Provides contraception for 2-3 years.

• Efficacy and side effects similar to Norplant.

Jadelle:

• Two rods containing 75mg levonorgestrel crystals.

• Rods: 43mm long, 2.5mm wide.

• Lasts 5 years.

• Easier insertion and removal than Norplant.

• Norplant and Jadelle are bioequivalent over 5 years.

Injectable Contraception

Depo-Provera (Depot medroxyprogesterone acetate):

• Dose: 150mg IM (gluteal or deltoid) every 3 months.

• Mechanism: High progestin peaks inhibit ovulation and thicken cervical mucus (blocks LH surge).

• Injection timing: Within first 5 days of menstrual cycle, otherwise back-up for 2 weeks.

• Technique: Deep IM by Z-track, do not massage.

Advantages:

• Easy to use, no daily or coital action required

• Safe, no serious health effects

• As effective as sterilization, IUCD, and implants

• Free from estrogen-related problems

• Private, not detectable

• Enhances lactation

• Has non-contraceptive benefits

Disadvantages:

• Irregular menstrual bleeding

• Breast tenderness

• Weight gain

• Depression

• Cannot be removed

• Delayed return to fertility

• Regular injections required

• No STI/HIV protection

Absolute contraindications:

• Pregnancy

• Unexplained genital bleeding

Noristerat (Norethisterone enanthate):

• Dose: 200mg every 2 months.

• Similar to Depo-Provera in all areas.

Intrauterine Contraception

Types of IUDs:

• Copper IUDs (e.g., TCu-380A)

• Hormone-releasing IUDs (LNG-IUS, e.g., Mirena)

Mechanism of action:

• Produces an intrauterine environment that is spermicidal and interferes with implantation.

• Ovulation is not affected. The IUCD is NOT an abortifacient (abortifacient means "causing abortion").

Efficacy:

• First-year failure rate: approximately 3%

• Expulsion rate: 10%

• Removal rate (bleeding and pain): 15%

• Non-medicated IUDs never need replacement.

Timing of insertion:

• Can be inserted at any time: after delivery, abortion, during menstrual cycle, or at Caesarean section.

Contraindications to IUCD use:

• Presence of pelvic infection (current or within 3 months)

• Undiagnosed genital tract bleeding

• Suspected pregnancy

• Distortion of uterine cavity (fibroids, congenital malformation)

• Past history of ectopic pregnancy

• Trophoblastic disease

• For CuT380A: Wilson's disease and copper allergy

Pregnancy with IUD in situ:

• Spontaneous abortion risk: 40-50%

• If pregnancy diagnosed and strings visible at <12 weeks: remove IUD.

• Removal may trigger abortion; may leave if ≥12 weeks or strings not visible.

• Preterm labour and birth: incidence increased 4-fold.

Missing strings – causes:

• Thread coiled inside

• Thread torn through

• Device expelled unnoticed

• Device perforated uterine wall (in peritoneal cavity)

• Device pulled up by growing uterus in pregnancy

• Identification method: Ultrasonography

Natural Family Planning

Methods:

• Coitus interruptus

• Fertility awareness methods:

  • Billings (cervical mucus)

  • Basal body temperature

  • Calendar (rhythm method)

• Lactational amenorrhoea (LAM)

Coitus Interruptus

• Removal of penis from vagina before ejaculation.

• First-year failure rate: 18%.

• Some sperm may be released before ejaculation.

• Better than no method.

Fertility Awareness

• Observing naturally occurring signs and symptoms of the fertile phase.

• Takes into account sperm viability in female tract and ovum lifespan.

Methods of fertility awareness:

• Calendar method: Fertile period calculated.

• Cervical mucus method: During fertile period, mucus is copious; during absolute infertile period, no mucus.

• Basal body temperature method: Rise in temperature of 0.5°C for 3 days indicates luteal phase.

Lactational Amenorrhoea Method (LAM)

• High prolactin inhibits pulsatile GnRH secretion → lactational amenorrhoea and anovulation.

• Only amenorrhoeic women who exclusively breastfeed at regular intervals (including nighttime) during first 6 months have protection equivalent to oral contraception.

• With menstruation or after 6 months, risk of ovulation increases.

• Supplemental feeding increases risk of ovulation (and pregnancy) even in amenorrhoeic women.

Breastfeeding and Contraception – The Rule of 3s

• With FULL breastfeeding: Start contraceptive method in the 3rd postpartum month.

• With PARTIAL or NO breastfeeding: Start contraceptive method during the 3rd postpartum week.

Effect on breast milk:

• Combined oral contraceptives (even low doses) diminish quantity and quality of breast milk.

• Progestogen-only contraceptives do not affect breastfeeding.

Sterilization

• Female and male sterilization are permanent, highly effective methods.

• Indicated in clients with satisfied parity or medical conditions precluding pregnancy.

Female Sterilization

• Mechanical blockage / excision of both fallopian tubes.

• Can be done via laparoscopy, laparotomy, or mini-laparotomy.

• Timing: during Caesarean section, puerperal, or interval.

Male Sterilization (Vasectomy)

• Excision of the vas deferens to prevent release of sperm during ejaculation.

• Easier, quicker, and more straightforward than female sterilization.

• Not effective immediately: may take 3-4 months.

• Alternate method should be used until azoospermia is confirmed.

Emergency Contraception

• Can prevent pregnancy after unprotected intercourse, method failure, or incorrect method use.

• Helps reduce unplanned pregnancies (many result in unsafe abortion).

Timing:

• Pills: within 72 hours of unprotected sex.

• IUCD: can be inserted up to 5 days after unprotected sex.

Methods:

Progestin-only pills (POP):

• Single dose: 1500mcg levonorgestrel, OR

• Two doses of 750mcg levonorgestrel taken 12 hours apart.

• Examples: Ovrette (20 tablets per dose, each 0.0375mg), Microlut/Microval/Norgestron (25 tablets per dose, each 0.03mg).

IUCD:

• Copper T inserted within 120 hours (5 days) of unprotected intercourse.

Combined oral contraceptive pills (COC):

• Two doses 12 hours apart. Each dose must contain at least 100µg ethinyl estradiol (EE) and 500µg levonorgestrel.

• Examples (2 tablets per dose): PC-4, Eugynon 50, Neogynon, Noral, Nordiol, Ovidon, Ovral, Ovran (each tablet contains 50µg EE + 0.25mg or 0.50mg levonorgestrel).

• Examples (4 tablets per dose): LoFemenal, Microgynon 30, Nordette, Ovral L, Rigevidon (each tablet contains 30µg EE + 0.15mg or 0.30mg levonorgestrel).