Obstetrics & Gynecology confusion pairs
19 Obstetrics & Gynecology topics students commonly mix up on Step 2 CK, each with the fastest separator, a side-by-side comparison, and a free practice question.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
- PROM vs PPROMGestational age threshold of 37 weeks is the immediate decision point separating PROM from PPROM management.
- Preeclampsia vs EclampsiaOccurrence of seizure is the immediate discriminator that upgrades preeclampsia to eclampsia.
- Threatened miscarriage vs Inevitable miscarriageCervical os status on pelvic exam.
- Preterm labor vs Term laborGestational age threshold of 37 completed weeks with true labor cervical change.
- Ectopic pregnancy vs Threatened miscarriageNo intrauterine pregnancy on transvaginal ultrasound above discriminatory beta-hCG level indicates ectopic pregnancy until proven otherwise.
- Preeclampsia vs HELLP syndromePlatelets below 100000/uL with hemolysis marks HELLP syndrome.
- Endometrial cancer vs Cervical cancerPostmenopausal bleeding with endometrial thickness above 4 mm directs to endometrial biopsy, not cervical colposcopy-first pathway.
- Placenta previa vs Placental abruptionPlacenta over the internal cervical os on transvaginal ultrasound identifies placenta previa.
- Pelvic inflammatory disease vs Ovarian torsionSudden unilateral pelvic pain with vomiting and an enlarged ovary on ultrasound points to ovarian torsion.
- Postpartum hemorrhage atony vs Postpartum hemorrhage non-atonyUterine tone on bimanual exam is the first branch point: boggy uterus means atony, firm uterus means search trauma, tissue, or thrombin…
- Polycystic ovary syndrome vs Hypothyroid amenorrheaTSH above 10 mIU/L with low free T4 identifies hypothyroid amenorrhea rather than polycystic ovary syndrome.
- Endometriosis vs AdenomyosisA diffusely enlarged boggy uterus on bimanual exam points to adenomyosis.
- Gestational diabetes vs Pre-gestational diabetesDiabetes-range hyperglycemia documented before 20 weeks is the immediate branch point to pre-gestational diabetes.
- Ovarian cancer vs Ovarian cyst benignComplex solid adnexal morphology with ascites on transvaginal ultrasound is the key discriminator for ovarian cancer risk.
- Group B strep pregnancy vs Group B strep neonatePositive maternal GBS status in labor triggers prophylaxis, while a symptomatic newborn triggers immediate sepsis treatment.
- Vaginitis BV vs Vaginitis trichomonasMotile trichomonads on wet mount separate trichomoniasis from bacterial vaginosis.
- Gestational HTN vs Chronic HTN in pregnancyHypertension first appearing after 20 weeks is gestational until proven otherwise.
- Spontaneous abortion complete vs Spontaneous abortion incompleteRetained products on ultrasound separate incomplete from complete abortion.
- Vaginitis candida vs Vaginitis BV/trichomonasNormal vaginal pH with yeast forms on KOH separates Candida from BV or trichomoniasis.