OB/GYN Shelf Exam: How to Score 90th+ Percentile
You're mid-rotation, running on coffee, and you just found out the OB/GYN Shelf is in four weeks.
Deep breath. You've got this.
The OB/GYN Shelf exam is actually one of the most manageable clerkship exams — if you know how to approach it. The content is narrower than medicine or surgery, the topics are predictable, and with the right plan, you can cover everything two or three times before test day.
This guide breaks down exactly what to study, which resources to use, and how to build a schedule that gets you above the 90th percentile.
What Exactly Is the NBME OB/GYN Shelf Exam?
The NBME OB/GYN Shelf is a 110-question, single-best-answer test you take at the end of your OB/GYN clerkship. You get 165 minutes. The format is identical to the Step exams — every question is a clinical vignette.
Here's the quick breakdown from the NBME's official content outline:
| What's Tested | % of Exam |
|---|---|
| Pregnancy, Childbirth & Postpartum | 40–45% |
| Female Reproductive System & Breast | 40–45% |
| Other (endocrine, multisystem, ethics) | 10–20% |
| How It's Tested | % of Exam |
|---|---|
| Diagnosis | 45–50% |
| Management & Pharmacotherapy | 20–25% |
| Prevention & Screening | 13–17% |
| Basic Science Concepts | 8–12% |
| Where It's Set | % of Exam |
|---|---|
| Outpatient/Ambulatory | 70–75% |
| Inpatient | 15–20% |
| Emergency Department | 5–10% |
Three things that jump out:
The exam is a near-even split between OB and GYN. Nearly three-quarters of it is outpatient, so think prenatal visits and contraception counseling, not emergency C-sections. And half the exam is pure diagnosis, meaning pattern recognition is everything.
Understanding OB/GYN Shelf Exam Percentiles
Your raw score converts to a national OB/GYN Shelf exam percentile: a ranking of how you performed compared to every other med student who took the same exam.
Why does this matter? Because OB/GYN Shelf percentiles directly determine your clerkship grade at most schools.
Here's a general sense of where the cutoffs fall (based on 2025–2026 data from schools like Texas Tech and UT Health Science Center):
| Percentile | What It Usually Means |
|---|---|
| 5th–10th | Minimum passing score |
| 55th | High Pass cutoff at many schools |
| 75th–80th | Honors cutoff at many schools |
| 90th+ | Top-tier performance |
A few things worth knowing about NBME Shelf exam scoring:
Percentiles aren't static throughout the year. Students who test later in the academic year are competing against a higher-performing national cohort (because those students have more rotations under their belt). So a "lower" raw score in Q4 might still reflect the same caliber of knowledge as a "higher" score in Q1.
With Step 1 now pass/fail, Shelf scores have become one of the most important objective metrics in your residency application. Some schools report them directly to programs. If you're gunning for OB/GYN, Family Medicine, or a competitive specialty, a strong Shelf score is a real differentiator.
High Yield OB/GYN Shelf Topics You Can't Skip
This section is the high yield OB/GYN shelf cheat sheet. These topics appear over and over across UWorld, AMBOSS, NBME practice forms, and student recall.
Obstetrics Side (40–45% of the exam)
Prenatal Care and Screening. Know the timeline cold — first-trimester screen, quad screen, glucose challenge at 24–28 weeks, GBS at 36–37 weeks, Rh testing, safe vaccinations. This is the single most commonly tested category.
Preeclampsia and Hypertensive Disorders. Diagnostic criteria for preeclampsia vs. eclampsia vs. HELLP. When to give magnesium. When to deliver. This will almost certainly be on your exam.
Postpartum Hemorrhage. Uterine atony is the cause until proven otherwise. Know the stepwise management: massage, uterotonics, balloon tamponade, surgery.
Fetal Heart Rate Tracings. Accelerations = reassuring. Early decels = head compression (benign). Late decels = placental insufficiency (bad). Variable decels = cord compression. Know when to intervene and when to watch.
Antepartum Bleeding. Placenta previa (painless, no digital exam) vs. abruption (painful, board-like abdomen). Different presentations, completely different management.
Teratogens. Isotretinoin, ACE inhibitors, valproic acid, warfarin, alcohol, and lithium. Know the drug and the fetal effects it causes.
Labor and Delivery. Stages of labor, arrest disorders, Bishop score, and cesarean indications.
Ectopic Pregnancy. Classic triad (amenorrhea + pain + bleeding), methotrexate criteria, and surgical indications.
Gestational Diabetes. Screening approach, diet vs. insulin, fetal complications.
Gynecology Side (40–45% of the exam)
Contraception. Every method — mechanism, contraindications (especially for those who can't get estrogen), and counseling. Very high yield.
Vaginitis and STIs. Bacterial vaginosis (clue cells, pH > 4.5, fishy smell) vs. candida (hyphae, pH < 4.5) vs. trichomoniasis (motile organisms, strawberry cervix). Know TORCH infections and their neonatal effects.
Cervical Cancer Screening. When to start Pap smears, screening intervals, HPV co-testing, and what to do with abnormal results. Free points if you've memorized the guidelines.
Abnormal Uterine Bleeding. PALM-COEIN classification. Workup differs by age — reproductive-age women vs. postmenopausal bleeding get different algorithms.
Ovarian Tumors. Epithelial vs. germ cell vs. sex cord–stromal. Know the classic associations: dermoid cyst in young women, serous cystadenocarcinoma as the most common malignant type, and granulosa cell tumors producing estrogen.
Breast Pathology. Screening guidelines, workup of a palpable mass, BI-RADS, fibroadenoma vs. cyst vs. malignancy.
Urinary Incontinence. Stress vs. urge vs. overflow — differentiate by history and know first-line treatment for each.
Amenorrhea. Primary vs. secondary workup. PCOS, hypothalamic amenorrhea, Asherman syndrome, and premature ovarian insufficiency.
Endometriosis and Fibroids. Presentation, imaging, when to treat medically vs. surgically.
Menopause. Hot flashes, hormone therapy (who qualifies, who doesn't), vaginal atrophy management.
Best Resources for an OB/GYN Shelf Review
If you've spent any time on OB/GYN Shelf Exam Reddit threads, you know that resource debates can get heated. Here's the consensus view, distilled.
The Essentials
UWorld Step 2 CK — OB/GYN section. The gold standard. Questions mirror NBME style. Explanations are detailed enough to teach you the topic, not just the answer. Use "Shelf Review" mode. Start on Day 1 in tutor mode. Switch to timed blocks in the final two weeks.
NBME practice exams. Nothing predicts your real score better. Take 3–4 over the course of your rotation. Review every question, right and wrong.
Highly Recommended
AMBOSS Qbank + Knowledge Library. 400+ OB/GYN Shelf exam practice questions with concise explanations. The knowledge library is also a fantastic, quick reference during rotations. Many students on forums call this their highest-yield single resource.
Case Files: OB/GYN. A case-based format that builds the exact diagnostic reasoning the NBME tests. One of the best review books for this specific shelf.
APGO uWISE. Topic-organized questions are great for targeted review of weak areas. Many clerkships give free access. Explanations are short, so you can burn through volume quickly.
Nice-to-Have Supplements
Divine Intervention Podcasts. OB/GYN rapid review episodes. Perfect for commuting. Many students listen to these the day before the exam.
Online MedEd. Short whiteboard video lectures. Good for a high-level overview early in the rotation.
Anki (AnKing OB/GYN deck). Spaced repetition for factual details. Small daily batches throughout the rotation compound over time.
How to Study for the OB/GYN Shelf: A 6-Week Plan
Figuring out how to study for the OB/GYN Shelf comes down to one principle: start questions early and build in checkpoints. Don't wait until you "feel ready." The question bank is the learning.
Here's a Shelf exam study schedule for a standard 6-week rotation.
Week 1 — Jump In
Start UWorld in tutor mode. Aim for 20–30 questions a day. You'll miss a lot. That's the point: every wrong answer is a concept you're locking in.
Begin a textbook (Case Files works well) with a focus on obstetric fundamentals. Start Anki if you're using it. Listen to overview podcasts during your commute.
Week 2 — Build Momentum
Keep the same UWorld pace. You should be roughly halfway done by the end of this week. Shift your textbook reading toward gynecology. Add AMBOSS if time allows. Note which topics you're consistently struggling with.
Week 3 — Check Yourself
Take your first NBME practice exam under timed conditions. This is your diagnostic — don't skip it. Identify your 3–5 weakest areas and spend extra time there over the next several days. Keep pushing through UWorld (aim for 70–80% done).
Week 4 — Finish and Review
Finish UWorld. Start reviewing your incorrects. This is arguably the highest-yield study activity available to you. Use uWISE for targeted practice on weak areas. Wrap up your textbook.
Week 5 — Simulate
Take a second NBME practice exam. Compare your score to Week 3. Switch UWorld to timed random blocks to simulate real exam conditions. Review rapid review materials. Use your textbook only as a reference.
Week 6 — Sharpen and rest
Take 1–2 more NBME practice exams early in the week. Finish reviewing the incorrects. Do targeted AMBOSS or uWISE blocks for any remaining weak spots. The day before: light review only, then sleep. Seriously, sleep matters more than one more cram session.
The magic number: Aim for 3–4 total NBME practice exams. They're the single best predictor of your real shelf score.
How to Honor the OB/GYN Shelf: What Top Scorers Do Differently
Knowing how to honor the OB/GYN Shelf isn't just about logging more hours. It's about studying smarter. Here are seven things students who hit the 90th percentile consistently do.
They master "normal" first. The OB/GYN shelf loves testing your ability to recognize a normal finding. Physiologic anemia of pregnancy, increased GFR, and round ligament pain. All of these sound alarming in a question stem, but they're normal. If you don't know what's normal, you'll over-diagnose everything.
They think outpatient. 70–75% of the exam is set in an ambulatory clinic. That means prenatal care, contraception counseling, screening guidelines, and well-woman visits. Students who only study L&D emergencies leave a huge chunk of the exam on the table.
They memorize screening guidelines. When do you start cervical cancer screening? What's the Pap interval? When do you order a glucose tolerance test? These are pure recall questions with no wiggle room, and they show up frequently. Free points.
They review correct answers too. You often pick the right answer for the wrong reason. Reading the explanation for questions you got right catches these gaps and reinforces proper clinical reasoning.
They don't ignore ethics. Informed consent, adolescent confidentiality, intimate partner violence screening, and shared decision-making around contraception. A small but consistent slice of the exam. Easy points if you've thought about them. Frustrating points to lose if you haven't.
They connect wards to studying. Saw preeclampsia today? Review the algorithm tonight. Clinical exposure paired with active study is the most powerful combination in medical education. Cases you've seen in person stick in a way that textbook reading alone never will.
They take more practice exams. Three to four NBME forms, not one. Every practice exam identifies blind spots, builds stamina, and makes the real thing feel routine.
Five Mistakes That Kill OB/GYN Shelf Scores
Waiting to start UWorld. This is the #1 mistake. The question bank is a learning tool, not a final exam. Start on Day 1. The early wrong answers are where the deepest learning happens.
Underpreparing obstetrics. Gynecology feels familiar from preclinical pathology. Obstetrics is brand new. Students naturally gravitate toward what's comfortable and end up underprepared for 40–45% of the test.
Only using one resource. UWorld is essential but usually not enough alone for the 90th percentile. Layer in a textbook, NBME forms, and at least one additional question bank.
Skipping practice exams. Without NBME practice forms, you're guessing at your readiness. These exams are the closest thing to the real test that exists.
Pulling an all-nighter. Whatever you gain from cramming the night before, you lose in cognitive function on exam day. The Shelf tests clinical judgment, and judgment requires a rested brain.
Exam Day Tips
Get there early. Give yourself time to settle in. Test-day stress is real; don't add logistics on top of it.
Read every word of the stem. OB/GYN vignettes bury clues in patient age, gestational age, vital signs, and lab values. A 22-year-old with vaginal bleeding gets a different workup than a 62-year-old with vaginal bleeding. The details matter.
Pace yourself. You have about 90 seconds per question. If something stumps you, flag it and come back to it. Don't let one hard question burn five minutes.
Trust your preparation. If you've done UWorld, taken multiple NBMEs, reviewed your incorrects, and followed a solid OB/GYN shelf review plan, the exam will not surprise you. The topics are predictable. The format is familiar. You've seen these questions before.
The Bottom Line
Scoring in the 90th percentile on the OB/GYN Shelf exam is not about being a genius. It's about being consistent.
Start UWorld on Day 1. Supplement with AMBOSS, Case Files, or uWISE. Take 3–4 NBME practice exams. Review your incorrects obsessively. Focus on high-yield OB/GYN Shelf topics. Connect what you see in the clinic to what you study at night. And sleep before the exam. If you follow this plan through your rotation, you'll walk into exam day knowing you've seen nearly everything the NBME can throw at you.
And if you need guidance or expert help with your OB/GYN Shelf prep, we offer 1-on-1 Shelf exam tutoring here at MedBoardTutors. Schedule a free tutoring consultation now to find out how we can help you reach your goal score.
