Harvey's Garden

Contraception

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aliasescontraceptives, OCPs

6 min read

Hormonal contraception

  • Mechanism of Action
    • Hormonal contraceptives utilize synthetic hormones, typically a combination of estrogen and progestin, or progestin-only.
    • Estrogen Component (e.g., Ethinyl estradiol):
      • Suppresses FSH release from the pituitary via negative feedback.
      • This prevents the development of a dominant ovarian follicle, thus inhibiting ovulation.
    • Progestin Component (e.g., Levonorgestrel, Norethindrone, Drospirenone):
      • Suppresses LH surge, which is the primary trigger for ovulation.
      • Thickens cervical mucus, creating a barrier that prevents sperm penetration.
      • Thins the uterine endometrium, making it less suitable for implantation.
    • Progestin-only methods rely more heavily on thickening cervical mucus and thinning the endometrium, with ovulation inhibition being less consistent (especially with low-dose pills).
  • Types of Hormonal Contraception
    • Combined Hormonal Contraceptives (CHCs) - contain both estrogen and progestin.
      • Oral Contraceptive Pills (OCPs): Most common form, taken daily. Efficacy is >99% with perfect use, but closer to 91% with typical use.
      • Transdermal Patch: Applied weekly for 3 weeks, followed by a patch-free week.
      • Vaginal Ring: Inserted for 3 weeks, followed by a ring-free week.
    • Progestin-Only Contraceptives (POCs) - indicated for patients with contraindications to estrogen (e.g., smokers >35, history of VTE, migraine with aura).
      • Progestin-Only Pills (POPs or “minipill”): Must be taken at the same time each day due to lower hormone dose.
      • Injectable Contraception (e.g., Depo-Provera): Administered every 3 months. Associated with potential for delayed return to fertility and decreased bone mineral density with long-term use.
      • Subdermal Implant (e.g., Nexplanon): A small rod inserted in the upper arm, effective for 3 years. Highly effective (>99%) due to user independence. c
      • Hormonal Intrauterine Device (IUD) (e.g., Mirena, Kyleena): T-shaped device placed in the uterus, effective for 5-8 years depending on the brand. Works primarily by local progestin effects on mucus and endometrium. Highly effective (>99%).
  • Key Side Effects & Adverse Events
    • Common Side Effects (often improve after 2-3 months):
      • Breakthrough bleeding/spotting (especially common with POPs and in the first few cycles of CHCs).
      • Headaches, nausea, breast tenderness, bloating.
      • Mood changes.
    • Serious Adverse Events (mainly associated with estrogen in CHCs, ):
      • Venous Thromboembolism (VTE): ↑ risk of DVT and PE. Risk is highest in women who smoke, are obese, or have thrombogenic mutations.
      • Hypertension: Estrogen can increase blood pressure. c
      • Stroke & Myocardial Infarction: Risk is significantly elevated in women who smoke and are over age 35.
      • Hepatic Adenoma: A rare, benign liver tumor.
      • Gallbladder Disease: Increased risk of cholelithiasis.
  • Absolute Contraindications to Combined Hormonal Contraceptives t
    • Hx of VTE (DVT/PE), stroke, or ischemic heart disease.
      • Rationale: Estrogen increases hepatic production of coagulation factors (VII, X, fibrinogen) and decreases Antithrombin III, creating a hypercoagulable state.
    • Smoker >35 years old (>15 cigarettes/day).
      • Rationale: Smoking causes endothelial damage; estrogen induces hypercoagulability.
    • Severe/uncontrolled hypertension (>160/100 mmHg).
    • Migraine with aura (increased stroke risk).
      • Rationale: Patients with migraine with aura have a baseline ↑ risk of ischemic stroke. Adding estrogen (thrombogenic) further amplifies this risk.
    • Current breast cancer.
    • Active or severe liver disease (cirrhosis, liver tumor).
    • Known thrombogenic mutations (e.g., Factor V Leiden, Protein C/S deficiency).
    • <21 days postpartum due to increased VTE risk.
  • Non-Contraceptive Benefits (primarily CHCs)
    • Regulation of menstrual cycles, treatment for dysmenorrhea and menorrhagia.
    • Treatment for acne and hirsutism.
    • Management of symptoms related to PCOS and endometriosis.
    • ↓ risk of ovarian and endometrial cancer.
    • ↓ risk of benign breast disease.

Intrauterine devices

Tip

  • Combined OCPs (COCPs) work primarily by suppressing ovulation via systemic inhibition of the hypothalamic-pituitary-gonadal (HPG) axis.
  • IUDs (both Copper and Levonorgestrel) work primarily via local uterine mechanisms (spermicidal/cervical mucus barrier) and largely do not interfere with ovulation (ovulatory cycles are preserved in the majority of users).
  • IUD Classification & Selection
    • Copper IUD (Cu-IUD): Non-hormonal (lasts 10–12 yrs).
      • Indications: Preferred in pts w/ hormone-sensitive conditions (e.g., active breast cancer); most effective emergency contraception (EC) within 5 days (120 hrs) of unprotected coitus (unaffected by BMI).
      • Contraindications: Wilson disease, copper allergy, severe baseline dysmenorrhea/hypermenorrhea.
      • Side Effects: Increased menstrual bleeding and dysmenorrhea (manage w/ NSAIDs). c2
    • Levonorgestrel IUD (LNG-IUD): Progestin-only (lasts 3–8 yrs).
      • Indications: 1st-line medical therapy for heavy menstrual bleeding (HMB), dysmenorrhea, adenomyosis, and endometrial hyperplasia without atypia. c
      • Contraindications: Active breast cancer (within past 5 yrs), severe liver disease.
      • Side Effects: Spotting initially, progressing to high rates of amenorrhea (benign; reassure pt).
  • Universal Contraindications (Both Cu-IUD & LNG-IUD)
    • Ectopic pregnancy
      • Although patients with an IUD have a lower absolute risk for ectopic pregnancy (due to overall lower rates of pregnancy), they are at higher risk for extrauterine implantation if pregnancy occurs.
    • Unexplained abnormal uterine bleeding (AUB) (eval required prior to placement). c
    • Active pelvic infection (PID, purulent cervicitis, active STI).
    • Anatomic uterine cavity distortion (e.g., submucosal fibroids, uterine septum).
    • Active cervical or endometrial cancer.
  • High-Yield Clinical Management Scenarios
    • Missing Strings / Perforation: Order Pelvic US 1st. If IUD not seen in uterus, order Abdominal X-ray to locate intraperitoneal IUD -> schedule laparoscopic removal. (Perforation risk is highest in breastfeeding or postpartum < 8 wks).
    • PID w/ IUD in situ: Start empiric broad-spectrum Abx immediately and leave IUD in place. Remove IUD only if no clinical improvement after 48–72 hrs.
    • Pregnancy w/ IUD in situ: Perform immediate Pelvic US (high relative risk of ectopic). If intrauterine pregnancy and strings visible, remove IUD immediately to decrease abortion and septic risks.
    • Actinomyces israelii on Pap Smear:
      • Asymptomatic: No treatment required; keep IUD in place.
      • Symptomatic (pelvic pain, mass, fever): Remove IUD and treat w/ Penicillin G.
    • Asymptomatic Positive STI post-insertion: Treat w/ targeted Abx; do not remove IUD.

Emergency contraception

  • Efficacy Ranking: Cu-IUD / 52-mg LNG-IUD (> 99%) > Ulipristal (> 98%) > Oral Levonorgestrel (~85%) > Yuzpe.
  • IUD Options (Copper IUD / 52-mg LNG-IUD):
    • Timing: Up to 120 hrs (5 days) post-UPSI.
    • Efficacy: > 99% (most effective overall); unaffected by high BMI.
    • Key Notes: Provides immediate long-term LARC. CI in acute PID, purulent cervicitis, or uterine distortion.
  • Ulipristal Acetate (UPA):
    • Timing: Up to 120 hrs (5 days) (efficacy does not decline over time).
    • Mechanism: SPRM; delays ovulation even after LH surge has started.
    • Key Notes: Rx only. Preferred oral choice for BMI > 30 kg/m² or 72–120 hrs. Must delay resuming regular hormonal OCPs for 5 days (use barrier for 14 days).
  • Levonorgestrel (LNG Oral):
    • Timing: Best within 72 hrs (3 days) (efficacy drops significantly after).
    • Mechanism: Synthetic progestin; ineffective once LH surge begins.
    • Key Notes: OTC without restrictions. Reduced efficacy in BMI > 25–30 kg/m². Resume regular OCPs immediately (use barrier for 7 days).
  • Yuzpe Method:
    • Timing/Regimen: High-dose EE + progestin within 72 hrs.
    • Key Notes: Least effective oral option; high rate of severe nausea/vomiting (requires antiemetics).
  • High-Yield Clinical Management Rules:
    • Vomiting < 2–3 hrs post-oral EC: Repeat oral dose or switch to IUD.
    • Pregnancy Status: Preg test not required prior to oral EC; non-abortifacient (safe if inadvertently given in pregnancy).
    • Sexual Assault: Give EC + empiric STI prophylaxis (Ceftriaxone + Doxycycline + Metronidazole) + HIV PEP.

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