Contraception questions show up everywhere on Step 1 and Step 2—often as quick “which method is best?” vignettes (postpartum, smoker, migraine with aura, teen with acne, heavy menses, STI risk). The trick is to organize methods in your head fast, then attach one-liners you can recall under pressure.
The “I POP SHeC” Acronym (fast sorting + quick recall)
Think of contraception as two buckets:
- I POP = the most testable “core” options (long-acting + pills)
- SHeC = the situational add-ons (barrier/behavioral/emergency)
The acronym
I POP SHeC
-
I = IUDs (Copper, Levonorgestrel)
-
P = Progestin-only methods (POP, implant, shot, LNG-IUD)
-
O = OCPs (Combined estrogen-progestin pills)
-
P = Patch / ring (Combined estrogen-progestin)
-
S = Sterilization
-
He = Hormonal emergency contraception
-
C = Condoms / barriers
Visual: Imagine a clinic “menu board” with I POP on the left (daily/long-term options) and SHeC on the right (situational/backup).
Quick-hit one-liners (shareable + test-ready)
I — IUDs
| Method | One-liner | High-yield USMLE facts |
|---|---|---|
| Copper IUD (Cu-IUD) | “Nonhormonal, best EC, makes periods heavier.” | Most effective emergency contraception if placed within 5 days of unprotected sex. MOA: copper is spermicidal → prevents fertilization. Can increase bleeding/cramps. |
| Levonorgestrel IUD (LNG-IUD) | “Local progestin → lighter periods, great for heavy bleeding.” | Thickens cervical mucus, thins endometrium. Often decreases menstrual bleeding (helpful in menorrhagia). |
Classic vignette clue: wants contraception + heavy menses → LNG-IUD. Wants EC + no hormones → Copper IUD.
P — Progestin-only methods (think: “safe when estrogen isn’t”)
This includes:
- POP (progestin-only pill)
- Etonogestrel implant
- DMPA shot (depot medroxyprogesterone)
- LNG-IUD (already above)
One-liner: “Progestin-only = cervical mucus plug + ovulation suppression (varies by method).”
High-yield facts by sub-method:
- Implant (etonogestrel): “LARC with irregular bleeding.”
- Very effective, long-acting, common side effect = unpredictable bleeding.
- DMPA shot: “Weight gain + delayed fertility + ↓ bone density.”
- High-yield adverse effects: decreased bone mineral density, weight gain, delayed return to fertility.
- POP: “Strict timing; great for breastfeeding.”
- Must take same time daily; often used when estrogen is contraindicated.
USMLE contraindication pearl: Estrogen increases thrombosis risk → when you must avoid estrogen, think progestin-only or nonhormonal.
O — OCPs (combined estrogen + progestin)
One-liner: “Combined pills regulate cycles and help acne—but estrogen raises clot risk.”
High-yield facts:
- Benefits: improved dysmenorrhea, menorrhagia, acne, and cycle control; lowers risk of endometrial and ovarian cancer (common testable association).
- Major risks (estrogen-related): VTE, stroke (especially with migraine with aura), hypertension (can worsen).
Absolute ‘don’t use estrogen’ Step-style flags (think thrombotic/stroke risk):
- Migraine with aura
- Smoker age ≥35
- History of VTE/thrombophilia
- Postpartum early period (especially if breastfeeding; timing varies, but early postpartum = higher VTE risk)
P — Patch / Ring (combined methods)
One-liner: “Same hormones/risks as OCPs—just different delivery.”
High-yield facts:
- Think estrogen contraindications apply (VTE/stroke risk concerns are the same).
- Convenient dosing can improve adherence (patch weekly; ring monthly), so these show up in “can’t remember daily pills” vignettes.
S — Sterilization
One-liner: “Permanent—best for done-with-childbearing.”
High-yield facts:
- Tubal ligation: prevents sperm from reaching egg (common boards phrasing: “blocks fertilization”).
- Vasectomy: contraception via male partner; requires post-procedure confirmation before relying on it (testable counseling point).
He — Hormonal Emergency Contraception
One-liner: “Delays ovulation; earlier is better.”
High-yield facts:
- Levonorgestrel EC: best when taken ASAP after unprotected sex.
- Ulipristal (selective progesterone receptor modulator): can be effective later than levonorgestrel (commonly tested as “more effective closer to day 5” concept).
- Mechanism emphasis: prevents/delays ovulation (not an abortifacient).
Most effective EC overall: Copper IUD (again—high-yield).
C — Condoms / Barriers
One-liner: “Condoms = contraception + STI protection.”
High-yield facts:
- Only barrier methods reduce STI transmission (especially latex condoms).
- Consider recommending condoms even when a patient uses another primary method (“dual protection” for STI risk).
The 10-second “which method should I pick?” decision map
1) Need STI protection?
- Condoms (often in addition to a more effective pregnancy prevention method)
2) Need the most effective, low-maintenance contraception?
- LARC: IUD (copper or LNG) or implant
3) Estrogen contraindicated (migraine with aura, smoker ≥35, VTE history, etc.)?
- Progestin-only (POP/implant/DMPA/LNG-IUD) or copper IUD
4) Heavy, painful periods?
- LNG-IUD (often best one-liner answer)
5) Need emergency contraception?
- Copper IUD (best)
- Hormonal EC (levonorgestrel/ulipristal) if IUD not chosen
Mini-table: “Most tested” adverse effects & counseling pearls
| Method | Classic side effect / counseling point |
|---|---|
| Copper IUD | Heavier bleeding, cramps |
| LNG-IUD | Lighter/absent periods over time |
| DMPA | ↓ bone density, weight gain, delayed fertility return |
| Combined OCP/patch/ring | VTE/stroke risk (avoid in migraine with aura, smoker ≥35) |
| Implant | Irregular bleeding |
A final memory hook (one line you can “hear” in your head)
“I POP SHeC: IUDs, Progestin-only, OCPs, Patch/ring—plus Sterilization, Hormonal EC, and Condoms.”
If you can recall that line, you can usually “open the right drawer” on exam day and grab the correct method fast.