CONTRACEPTION Flashcards
(28 cards)
Define contraception and contraceptives.
Contraception is the prevention of pregnancy. Contraceptives are the drugs or devices used to achieve this.
What is dual contraception?
Use of a contraceptive method plus a barrier method (e.g., condoms).
What is the Pearl Index and what does it measure?
The number of pregnancies per 100 women using a method for 1 year. Lower = more effective. Calculated as: pregnancies × 1200 / (# women × months used)
Characteristics of an ideal contraceptive?
Safe, effective, acceptable, accessible, reversible, non-interfering with sex, minimal side effects, easy to use, affordable.
Name two progestin-only injectables and their dosing schedule.
Medroxyprogesterone acetate (Depo-Provera): 150mg IM every 12 weeks
Norethisterone enanthate (Nur-Isterate): 200mg IM every 8 weeks
What is the main mechanism of progestin injectables?
Prevent ovulation by inhibiting GnRH and thickening cervical mucus.
Key advantages of injectable contraceptives?
Highly effective, long-acting, safe post-partum, protects against endometrial cancer and anaemia, convenient for unreliable users.
When are injectable contraceptives contraindicated?
If pregnancy is planned soon, unexplained vaginal bleeding, late injections (delays of >2–4 weeks).
What is the mechanism of action of COCs?
Progestin inhibits LH → no ovulation. Estrogen suppresses FSH → no follicle development.
Types of COC formulations?
Monophasic: uniform estrogen + progestin
Biphasic/Triphasic: variable hormone doses
Includes placebo tablets for cycle control
List common side effects of too much progestin.
Acne, hirsutism, mood changes, ↑ appetite, jaundice, yeast infections, non-cyclical weight gain
Absolute contraindications for COCs?
Pregnancy, undiagnosed bleeding, estrogen-sensitive cancer, liver disease, severe CV/migraine conditions.
What to do if a woman misses COC pills?
1 missed: take ASAP, continue as usual
≥2 missed: use backup for 7 days, consider EHC if missed in week 1
Missed in week 3: skip placebos, start new pack
Do antibiotics reduce the effectiveness of oral contraceptives (OCs)?
Yes, some antibiotics—particularly enzyme inducers—can lower the effectiveness of hormonal contraceptives, especially low-dose combined oral contraceptives (COCs).
How do antibiotics interfere with contraceptive effectiveness?
Broad-spectrum antibiotics can suppress intestinal flora
This affects enterohepatic recirculation of ethinylestradiol (EE)
Less EE is reabsorbed → lower plasma EE levels → risk of ovulation and pregnancy increases
What should patients do if taking enzyme-inducing antibiotics?
Use extra contraception (e.g., condoms) during and for 2 weeks after the antibiotic course
Consider high-dose EE pills (if appropriate) for long-term antibiotics
Be alert for breakthrough bleeding (BTB)—this may indicate reduced efficacy
How do POPs prevent pregnancy?
Inhibit LH surge, thicken cervical mucus, cause endometrial atrophy, and reduce tubal motility.
Differentiate copper vs hormonal IUDs.
Copper: toxic to sperm, lasts >10 years, non-hormonal
Hormonal (e.g., Mirena): releases levonorgestrel, thickens mucus, effective for 5 years
Advantages and disadvantages of IUDs?
✔️ Long-term, reversible, no daily use, minimal systemic effects
❌ Skilled insertion, initial bleeding, ↑ risk of infection if STI present
When can IUDs be inserted post-partum?
Within 48 hours or after 4 weeks. Avoid insertion in between due to infection risk.
Types and role of barrier methods?
Male/female condoms, diaphragms—used to prevent sperm from reaching egg. Essential for STI/HIV protection.
What is the time window for EHC effectiveness?
Within 72 hours (max 120 hrs) of unprotected sex. Sooner = better.
Common emergency contraceptive regimens?
Levonorgestrel 0.75mg x 2 or 1.5mg x 1
Combined: ethinyl estradiol 100μg + levonorgestrel 0.5mg
When is IUCD an option for emergency contraception?
Within 5 days (120 hrs) of unprotected intercourse.
