The Obstetrics & Gynecology (OB/GYN) examination is ARDMS’s specialty examination for the RDMS credential in obstetric and gynecologic sonography: approximately 170 questions in three hours — multiple-choice, hotspot, and PACSim questions — scored on a 300-to-700 point scale where 555 or better passes, covering the female reproductive system and the fetus across the first, second, and third trimesters. It is one half of a two-examination credential: the Sonography Principles and Instrumentation (SPI) examination must also be passed within five years, in either order. PassProfessor’s RDMS OB/GYN program is in the works, built to ARDMS’s published examination content.
This program is part of the expanding PassProfessor catalog — join the notify list and we’ll email you when enrollment opens.
OB/GYN sonography carries a double responsibility no other specialty quite shares: every examination has at least two patients in it, and the findings range from the routine anatomy survey to the anomalies that change a pregnancy’s course. The OB/GYN specialty examination is built to that shape — gynecologic anatomy and physiology on one side, three trimesters of obstetrics on the other, and the protocols, procedures, and physics that serve both running underneath. PassProfessor’s RDMS OB/GYN program is in the works as part of the expanding PassProfessor catalog, built on the content ARDMS publishes for the examination and organized the way the examination is organized, so preparation follows the specialty’s real structure rather than a textbook’s order.
Which examination is this?
This page covers one examination only: the Obstetrics & Gynecology (OB/GYN) specialty examination administered by the American Registry for Diagnostic Medical Sonography (ARDMS), a qualifying examination for the Registered Diagnostic Medical Sonographer (RDMS) credential with the OB/GYN specialty. It is not the SPI examination — Sonography Principles and Instrumentation is the separate physics examination every RDMS specialty shares, with its own PassProfessor program — and passing OB/GYN alone does not make you an RDMS: both examinations must be passed within five years of each other. It is also distinct from ARDMS’s other specialty examinations, including Abdomen and the separate Fetal Echocardiography credential, and from physician-side examinations administered through ARDMS’s companion council. This page concerns the sonographer-level RDMS OB/GYN examination.
What will the program cover?
Original practice questions, written to ARDMS’s published content. The program is being built from scratch against the content ARDMS publishes for the OB/GYN examination — the female reproductive system, the fetus in the first, second, and third trimesters, and the protocols, procedures, physics, and instrumentation that support them — so practice follows the examination’s real map of the specialty. No practice item is an actual examination item, a recalled item, or another provider’s material, and no item asks you to recite a code, section number, or citation: knowledge and image interpretation are tested, citations never are.
Image-first practice across the advanced item types. The real examination asks questions three ways: multiple choice, hotspot questions answered by marking directly on an image, and PACSim questions — ARDMS’s simulated clinical scenarios. The program’s design includes image-anchored practice that trains the skills those formats examine: locate the structure or the finding on the image, work the clinical scenario, then decide.
Results you can read by content area. Practice is organized by the examination’s content areas — gynecology, the three trimesters, and the supporting protocols and physics — so your results can be read area by area: a thin trimester shows while there is still time to repair it, instead of hiding inside an overall score.
Timed practice at the real sitting’s shape. The real examination gives you three hours for approximately 170 questions, including a five-minute survey. The program’s design includes sustained timed practice modelled on that shape, so pacing over image-heavy items is trained alongside knowledge.
What are the verified facts of the real exam?
| Fact of record | Detail |
|---|---|
| Credential | Registered Diagnostic Medical Sonographer (RDMS) with the OB/GYN specialty, from the American Registry for Diagnostic Medical Sonography (ARDMS) |
| Two-examination structure | The OB/GYN examination and the Sonography Principles and Instrumentation (SPI) examination must both be passed within five years of each other, in either order |
| Format | Approximately 170 questions in 3 hours (including a five-minute survey): multiple-choice, hotspot, and PACSim questions |
| Scoring | Pass or fail against a point scale of 300 to 700; a score of 555 or better passes. The scale is not a percentage |
| Content | The female reproductive system (gynecologic anatomy and physiology); the fetus in the first, second, and third trimesters; protocols and procedures; physics and instrumentation |
| Eligibility | You must meet one of ARDMS’s published prerequisite pathways (education and clinical sonography experience) before ARDMS accepts your application |
| Examination fee | $275, including a $100 non-refundable processing fee, as ARDMS publishes it (an additional $50 applies at test centers outside the U.S., Canada, and Mexico). Confirm the current fee when you apply |
| Retakes | You may reapply three days after an unsuccessful attempt, but must wait 60 days before retaking the examination |
How does the practice map to the examination?
ARDMS describes the OB/GYN examination as assessing the knowledge, skills, and abilities of the specialty across the female reproductive system and the fetus in all three trimesters, underpinned by protocols and procedures and by physics and instrumentation. The practice program is organized on the same map:
| Content area | What it carries |
|---|---|
| Gynecology — pelvic anatomy and physiology | The normal female reproductive system, its physiology and cycles, and the benign and pathological conditions sonography evaluates |
| Obstetrics — first trimester | Early pregnancy: confirmation, dating, viability, ectopic pregnancy, and first-trimester assessment |
| Obstetrics — second and third trimesters | The anatomy survey, fetal growth and wellbeing, anomalies, the placenta and cervix, multiple gestation, and late-pregnancy assessment |
| Protocols and procedures | Examination protocols, measurement technique, and the procedures of OB/GYN sonographic practice |
| Physics and instrumentation | The physics and instrumentation of OB/GYN imaging applied to the specialty’s examinations |
What does the gynecology content cover?
The non-pregnant half of the specialty: the anatomy and physiology of the female reproductive system — uterus, endometrium, myometrium, ovaries, adnexa — across the menstrual cycle and the lifespan, and the pathology the specialty evaluates: fibroids and other myometrial conditions, endometrial abnormalities, ovarian cysts and masses, pelvic inflammatory disease, and the sonographic workup of pain, bleeding, and infertility-related questions. Gynecology items reward the same discipline as the trimesters: normal first, in both planes and both approaches, so that the abnormal declares itself.
The cycle is the calendar of gynecologic sonography: what is normal depends on when in the cycle — and when in life — the patient is scanned.
What does the first-trimester content cover?
Pregnancy’s opening act, where the examination is often diagnostic rather than descriptive: intrauterine pregnancy confirmation and location, gestational sac and embryo assessment, dating by early measurement, viability, ectopic pregnancy and its signs, multiple gestation and chorionicity in its earliest determinable form, and the first-trimester markers and screening context. This content is unforgiving of approximate knowledge — the distinctions it tests (intrauterine versus ectopic, viable versus failing) are the distinctions the clinical day turns on.
What do the second- and third-trimester content cover?
The largest territory of the examination: the fetal anatomy survey system by system; biometry and growth assessment; amniotic fluid evaluation; placental location, grading, and abnormality; cervical assessment; fetal wellbeing testing; the detection and description of fetal anomalies; multiple gestation and its complications; and the maternal conditions that reshape a pregnancy’s surveillance. Preparation here is study of the normal survey until it is a reflex — every required view, every standard measurement — because anomaly items are, structurally, normal items with one detail wrong, and the candidate who has to think about what the normal view should show has no attention left for the detail.
An anomaly question is a normal question with one finding changed. Own the normal survey cold, and the anomalies identify themselves.
What do protocols, procedures, and physics cover?
The supporting frame. Protocols and procedures covers how OB/GYN examinations are actually performed: the standard examination components, measurement technique and its reproducibility, Doppler applications in the specialty, and the procedures that surround imaging. Physics and instrumentation applies the SPI’s foundation to this specialty’s specific demands — the transducers, settings, and artifacts of pelvic and obstetric imaging, and the safety principles, including output and exposure discipline, that govern scanning a pregnant patient. Candidates who treat the frame as minor meet a meaningful share of the examination unprepared.
How is the OB/GYN examination scored?
ARDMS scores the examination on a point scale from 300 to 700, and a score of 555 or better passes. The scale is not a percentage — 555 is not 79% of anything — and there is no published conversion from questions answered correctly to points; the standard is fixed against the content, not curved against other candidates. The two-examination structure adds a calendar dimension to scoring that pure format guides miss: wherever your SPI result sits, its five-year window frames your OB/GYN attempts, and a retake — available after a 60-day wait — consumes the same window. Plan the pair as one project, and a strong SPI result can never be stranded by an unplanned OB/GYN timeline.
Who can take this exam, and what does it certify?
Before ARDMS accepts an OB/GYN application, you must satisfy one of the prerequisite pathways ARDMS publishes — defined combinations of sonography education and clinical sonography experience, of which graduation from a CAAHEP-accredited sonography program is the most direct, with other pathways for candidates arriving through degrees with clinical experience or related credentials. The pathways are documented in ARDMS’s current prerequisite document; read it before applying, because the documentation requirements are specific and application fees are not returned for eligibility errors. If you are applying from a clinical background, ARDMS’s application process can also involve a Clinical Verification form for the specialty, as its application materials describe. Passing the OB/GYN examination and the SPI within five years of each other earns the RDMS credential with the OB/GYN specialty — the credential employers name for obstetric and gynecologic sonography — maintained thereafter under ARDMS’s renewal and continuing education requirements.
What makes this test demanding?
Three features. First, the two-patient problem: obstetric items routinely require tracking mother and fetus as separate but interacting subjects — a maternal condition, a fetal finding, a placental fact — inside one question. Second, the normal-survey dependency: anomaly detection is the specialty’s signature skill, and the examination tests it by requiring a reflex-level command of the normal anatomy survey that no amount of anomaly-list memorization replaces. Third, the item types: hotspot questions ask you to put a mark on the finding, and PACSim questions ask you to work a simulated clinical scenario, so knowledge that exists only as text underperforms knowledge that has been practised on images and in scenarios.
An honest note on format
PassProfessor practice questions are written and image-anchored items in the examination’s spirit; the real examination’s hotspot and PACSim formats are ARDMS’s own interactive item types, delivered at the test center, and no practice environment reproduces those interfaces exactly. ARDMS does not release its examination questions, and no provider can offer them. Practice here builds the knowledge and image interpretation the content requires; practice results are a study gauge — a way to see which areas are thin while there is time to repair them — not a prediction of a scaled score.
How should you use this page while the program is in the works?
- Join the notify list today. Enrollment is not open yet, and the notify list is how you hear the moment it is. While you wait, read the exam guide — it walks the two-examination structure, prerequisites, content areas, scoring, and study planning in full.
- Check your five-year window now. If the SPI is already passed, its date sets your OB/GYN deadline. If it is not, plan the pair as one project with two sittings and decide the order deliberately.
- Study from ARDMS’s published content now. The content areas summarized on this page are the syllabus; organizing your reading and your scanning review by them is useful work today, before any practice program opens.
- When the program opens, survey every area first. Early practice should touch gynecology, all three trimesters, and the supporting content, so your first picture of yourself is honest — then drill the areas that cost you, and finish with full timed sittings.
Frequently asked questions
How many questions are on the ARDMS OB/GYN exam? Approximately 170 questions in three hours, including a five-minute survey.
What types of questions does the OB/GYN exam use? Multiple-choice questions, hotspot questions answered by marking directly on an image, and PACSim questions — ARDMS’s simulated clinical scenario items.
What score passes the OB/GYN exam? A score of 555 or better on ARDMS’s 300-to-700 point scale, as ARDMS publishes it. The scale is not a percentage.
Do I need the SPI exam as well? Yes. The RDMS credential with the OB/GYN specialty requires both the OB/GYN specialty examination and the Sonography Principles and Instrumentation (SPI) examination, passed within five years of each other, in either order.
What does the OB/GYN exam cost? ARDMS publishes an examination fee of $275, including a $100 non-refundable processing fee; an additional $50 applies at test centers outside the U.S., Canada, and Mexico. Confirm the current fee when you apply. That is ARDMS’s fee, separate from any preparation program.
Who is eligible to apply for the OB/GYN exam? Candidates who meet one of ARDMS’s published prerequisite pathways combining sonography education and clinical experience — most directly, graduation from a CAAHEP-accredited sonography program. ARDMS’s current prerequisite document carries the exact pathways and documentation.
What happens if I do not pass? You may reapply after three days, but must wait 60 days before retaking the examination — and your five-year window for pairing with the SPI keeps running.
What content does the OB/GYN exam cover? The female reproductive system; the fetus in the first, second, and third trimesters; protocols and procedures; and physics and instrumentation — the content ARDMS publishes for the examination.
Is this the same as the Fetal Echocardiography credential? No. Fetal Echocardiography (FE) is a separate ARDMS credential with its own examination. This program covers the OB/GYN specialty examination for the RDMS.
Are these the real exam questions? No. Every question in the program is an original PassProfessor practice question written to the content ARDMS publishes for the examination. ARDMS does not release its examination questions, and no provider can offer them.
When will enrollment open? The program is in the works. Join the notify list on this page and we will email you when enrollment opens.
Disclaimer
PassProfessor is an independent exam-preparation provider; this program is not endorsed by, affiliated with, or sponsored by the American Registry for Diagnostic Medical Sonography (ARDMS), Inteleos, or Pearson VUE. ARDMS, RDMS, and SPI are marks of the ARDMS. This program is examination preparation only: the details on this page are drawn from the official sources recorded in the companion guide and are current as of November 2026; ARDMS’s official publications govern if anything here differs from them. The credential is awarded by ARDMS alone when its requirements are complete; this program confers no credential.