Obstetrics/Gynecology Registry Review Study Guide - Practice Flashcards

Flashcards cover major obstetrics/gynecology topics from pelvic anatomy to fetal development, placental pathology, adnexal pathology, obstetric Doppler, anomalies, and common ultrasound findings.

What are the bony boundaries of the true pelvis?

Sacrum, coccyx, and the innominate bones (ilium, ischium, pubic symphysis).

What line separates the true pelvis from the false pelvis?

Linea terminalis (from pubic symphysis to the sacral prominence).

Where is the true pelvis located in relation to the linea terminalis?

Deep and inferior (below the linea terminalis).

Which muscles comprise the pelvic diaphragm?

Levator ani and coccygeus.

Which uterine ligaments are described, and what is notable about their visualization on sono?

Broad ligaments, round ligaments, and cardinal ligaments; broad ligaments are the only ligaments visualized on sono, usually when pelvic ascites is present.

What arteries supply the uterus and what are the key endometrial arteries?

Uterine arteries (branches of the internal iliac); arcuate arteries (periphery of myometrium), radial arteries (deeper into myometrium), and straight/spiral arteries (basal and functional endometrium).

What is the venous drainage pattern for the uterus?

Uterine veins drain into internal iliac veins; the right ovarian vein drains into the IVC and the left ovarian vein drains into the left renal vein.

What are the peritoneal spaces in the pelvis relevant to ultrasound?

Retropubic space (space of Retzius) anterior to the bladder; vesicouterine pouch (anterior CDS); rectouterine pouch or pouch of Douglas (posterior CDS).

What are the main divisions of the uterus and their landmarks?

Fundus, corpus, isthmus (lower uterine segment in pregnancy), and cervix (internal and external os; external os opens into the vaginal canal).

What are the three layers of the uterus and the two layers of the endometrium?

Serosa (perimetrium), myometrium, endometrium; endometrium has basal (deep) and functional (superficial) layers.

How does the appearance of the endometrium change across the menstrual cycle on ultrasound (early vs late proliferative)?

Early proliferative: thin and echogenic (often <4 mm); Late proliferative: thickened 6–10 mm with the three-line sign (basal layer echogenic rim surrounding hypoechoic functional layer).

What are the four uterine positions/orientations described?

Anteversion, anteflexion, retroflexion, and retroversion.

Where do the Fallopian tubes extend from and what are their major segments?

From the cornu to the adnexa; segments are interstitial, isthmus, ampulla, and infundibulum with fimbriae.

Which portion of the Fallopian tube is the most common fertilization site?

The ampulla.

What is the ovaries’ dual blood supply and where do ovarian veins drain?

Ovarian arteries (from the aorta) and uterine arteries provide dual supply; right ovarian vein to the IVC, left ovarian vein to the left renal vein.

What prep is used for transabdominal vs transvaginal ultrasound of the pelvis?

Transabdominal: drink 32 oz of water and refrain from voiding; transvaginal: empty the bladder.

What is considered the normal thickness range for the endometrium in the early proliferative and late proliferative phases?

Early proliferative: ≤4 mm; Late proliferative: 6–10 mm with the three-line sign.

What are the cyclic phases of the normal menstrual cycle and their hormonal drivers?

Follicular (FSH-driven) with estrogen buildup; LH surge triggers ovulation; corpus luteum secretes progesterone (and some estrogen); if no pregnancy, progesterone falls and menses occurs.

How is the day of ovulation calculated from a cycle length?

Ovulation is day cycle length minus 14 (e.g., in a 36-day cycle, day 22 is ovulation).

What are the key first-trimester ultrasound milestones after conception?

5 weeks: gestational sac visible with hCG rise; 5.5 weeks: yolk sac appears with MSD ~10 mm; 6 weeks: fetal pole; cardiac activity usually by 5 mm CRL.

What are the defining features of a heterotopic pregnancy?

IUP coexisting with an ectopic pregnancy.

What is a pseudogestational sac?

An intrauterine-like sac seen in ectopic pregnancy that is not a true gestational sac.

What are the main forms of Gestational Trophoblastic Disease (GTD)?

Complete mole (absent fetus/GS, benign with malignant potential); Partial mole (coexisting IUP/GS); Invasive mole (chorioadenoma destruens); Choriocarcinoma.

Describe the common classifications of miscarriage terminology.

Threatened, inevitable, incomplete, complete, missed; incomplete has retained products of conception (RPOC); complete means the cavity is empty and the endometrium is thin.

What is placenta previa and its different types?

Placenta previa is placenta implanted near or over the internal os; types are complete (covers os), marginal (edge reaches os), and low-lying (edge within 2 cm of os).

What is placenta accreta spectrum and its components?

Accreta (adhesion to myometrium), increta (invasion into myometrium), and percreta (penetration through the uterus).

What are the three shunts in fetal circulation and their general purpose?

Ductus venosus (bypasses liver), foramen ovale (right to left atrium), ductus arteriosus (pulmonary to aorta) to optimize oxygen delivery to the body.

What Doppler findings are associated with malignancy in pelvic masses?

Low resistance with increased diastolic flow; RI < 0.4 and/or high end-diastolic flow.

What are the key adnexal masses and their ultrasound features?

Follicular cyst (simple, thin-walled), corpus luteum cyst (hemorrhagic or lacy), paraovarian cyst (near ovary, usually <2 cm), theca lutein cysts (bilateral, associated with high hCG).

What is a dermoid (mature cystic teratoma) and the classic ultrasound signs?

Benign germ cell tumor; features include “tip of the iceberg,” dermoid plug or mesh; may contain fats, hair, teeth.

What is Meigs syndrome?

Ascites and pleural effusion in the presence of a benign ovarian tumor.

What is the difference between endometrial hyperplasia and endometrial carcinoma risk factors?

Hyperplasia is thickened endometrium often due to unopposed estrogen; carcinoma risk increases with persistent unopposed estrogen exposure and is associated with postmenopausal bleeding and obesity.

What is the typical estrogen-producing ovarian tumor pair and its effect on the endometrium?

Thecoma and granulosa cell tumor; estrogen production can cause endometrial thickening and risk of hyperplasia or carcinoma.

Which ovarian tumors are not estrogen-producing and therefore not associated with endometrial thickening?

Fibroma and Brenner tumor.

What are the major ultrasound features of ovarian torsion?

Enlarged, heterogeneous ovary with diminished or absent blood flow on Doppler.

What is a corpus luteum of pregnancy and its ultrasound appearance?

Physiologic cyst maintained by hCG that secretes progesterone; typically simple or complex/hemorrhagic cyst in early pregnancy.

What are the common findings in pelvic inflammatory disease (PID) on ultrasound?

Endometritis, hydrosalpinx, pyosalpinx, complex adnexal masses such as TOA; acute PID shows thickened, heterogeneous endometrium and fluid.

What are the primary posterior cul-de-sacs names and their relations?

Vesicouterine pouch (anterior CDS) between bladder and uterus; rectouterine pouch (pouch of Douglas) between uterus and rectum.

What is the typical bladder position in early pregnancy and PID imaging?

Bladder and adnexal regions are evaluated; pelvic ascites can help visualize broad ligaments.

What are the main components used to document pathology in ultrasound in two planes?

Document location relative to organs/landmarks and measure masses in two planes.

What is the typical appearance of a serous vs mucinous ovarian cystadenocarcinoma on ultrasound?

Serous: large, bilateral cysts with thin septations; mucinous: larger, unilateral with thick septations and internal debris.

Which tumor types are associated with estrogen production and potential endometrial cancer risk?

Granulosa cell tumor and thecoma.

What imaging signs suggest congenital uterine anomalies like septate, bicornuate, or didelphys?

Ultrasound findings include two endometrial cavities or a divided uterine cavity; classification includes arcuate, bicornuate, subseptate, septate, didelphys, unicornuate.

What is a corkscrew sign or “lambda sign” in twinning?

Twin peak sign indicating dichorionic diamniotic (Di/Di) twinning on ultrasound.

What is TTTS and who is at risk?

Twin–Twin Transfusion Syndrome in monochorionic twins due to intertwin transfusion through placental vessels; donor and recipient have discordant amniotic fluid volumes.

What are signs of fetal hypoxia on Doppler in the fetal middle cerebral artery (MCA)?

Decreased resistance with increased PSV in MCA due to brain-sparing effect.

What is the significance of the umbilical artery waveform in placental insufficiency?

Abnormal flow patterns (high‑resistance, reduced diastolic flow) indicate placental insufficiency and potential IUGR.

What is the purpose of a nuchal translucency (NT) measurement in the first-trimester screen?

NT assesses risk for aneuploidy (Down syndrome, Trisomy 18, 13) when combined with maternal serum markers.

What are the major midline brain abnormalities associated with holoprosencephaly and their severity spectrum?

Alobar (most severe, no lobes), semilobar, and lobar (least severe) holoprosencephaly; associated with facial defects and T13.

What is the spindle sign in fetal head ultrasound and what condition is it associated with?

“Rhomboid” or rounded head shapes associated with ventriculomegaly/hydrocephalus; seen with severe brain anomalies.

What is anencephaly and how is it visualized on ultrasound?

Absence of cranial vault and brain tissue; coronal view may show frog‑like bulging eyes; elevated AFP.

What is anencephaly vs exencephaly?

Anencephaly: absence of the brain; Exencephaly: brain without a skull—misfused skull bones.

What is the typical placenta grading progression from the 1st to 3rd trimester?

Grade 0 in early to mid 1st; Grade 1 in late 2nd; Grade 2 in late 2nd to early 3rd; Grade 3 in postdates with irregular calcifications.

What are the two main fetal adverse conditions linked to Rh incompatibility?

Immune hydrops (erythroblastosis fetalis) and nonimmune hydrops from other causes.

What is the diagnostic significance of a thickened nuchal fold in the fetal neck in mid-trimester ultrasound?

Increased nuchal translucency/fold is a soft marker for aneuploidy such as Down syndrome and other syndromes.

Which placental abnormality is associated with placenta accreta spectrum and prior cesarean sections?

Placenta accreta/increta/percreta; loss of basal plate, placental lacunae, and increased peripheral vascularity.

What are the differences between complete and incomplete abortion on ultrasound?

Complete: no intrauterine contents; incomplete: retained products of conception with echogenic material in the cavity.

What finding distinguishes a hydrosalpinx on ultrasound?

Dilated, tortuous fallopian tube with fluid; may be seen as a sausage-shaped adnexal mass.

What is the most common genetic syndrome associated with a 4‑chamber heart defect and AVSD?

Trisomy 21 (Down syndrome) with associated AV canal defects.

What is the definition of a chorionicity and amnionicity in multiple gestations?

Dichorionic/diamniotic vs monochorionic/diamniotic vs monochorionic/monoamniotic based on placental sharing and amniotic membranes.

What is a cocoon-shaped term for bundled signs of midline brain anomalies such as holoprosencephaly?

Midline brain defects with CSP and CC absence; spectrum includes holoprosencephaly.

What is the role of hCG in early pregnancy and decidualization?

hCG maintains the corpus luteum, which secretes progesterone to support decidualization and endometrial receptivity.

What is a positive predictor sign of ectopic pregnancy on ultrasound?

Extrauterine gestational sac, adnexal ring sign, free fluid in the pelvis.

What are the characteristic ultrasound findings for a complete mole?

Vesicular, snowstorm pattern with high hCG; absence of fetus/GS and myometrial invasion risk.

What are the characteristic signs of a partial mole?

Coexisting intrauterine pregnancy with molar tissue; irregular, heterogeneous placental tissue.

What organ systems are commonly involved in VACTERL associations?

Vertebral defects, Anal atresia, Cardiac defects, Tracheoesophageal fistula, Esophageal atresia, Renal anomalies, Limb defects.

What is the clinical significance of a two-vessel umbilical cord?

Single umbilical artery; often associated with congenital anomalies, though not always.

What is the difference between a velamentous cord insertion and a marginal ( battledore) insertion?

Velamentous: vessels insert into membranes then traverse to placenta; marginal: insertion at placental edge.

What is vasa previa and why is it clinically important?

Vessels cross the internal os; risk of fetal exsanguination at labor; requires targeted imaging.

What is the clinical significance of a cystic hygroma?

Cystic lymphatic malformation in the neck; associated with Turner syndrome and aneuploidy.

What are the main components of a standard obstetric Doppler exam for placental assessment?

Uterine arteries and umbilical artery waveforms, assessing resistance and end-diastolic flow.

What is a paradoxical finding in TTTS donor vs recipient fluid volumes?

Donor: oligohydramnios; Recipient: polyhydramnios.

What is the yolk sac’s function in early pregnancy?

Yolk sac provides early hematopoiesis and is involved in fetal nourishment until placental circulation is established.

What is the significance of the third ventricle in fetal brain imaging?

Located near thalamus; ventricles help assess brain development and midline structures.

What is the clinical role of the placenta in assessing fetal well-being via Doppler?

Placental resistance measured via uterine and umbilical arteries helps assess placental insufficiency and risk of IUGR.

What are the key sonographic features of endometrial polyps?

Focal thickening of endometrium with possible vascularity and a stalk; SIS (saline infusion sonohysterography) can aid visualization.

What is the significance of a positive MEIGS syndrome?

Ascites and pleural effusion with a benign ovarian tumor.

What is the difference between a simple and hemorrhagic ovarian cyst on ultrasound?

Simple: anechoic, thin-walled, posterior enhancement; hemorrhagic: echogenic with posterior enhancement and internal complexity.

What is the typical appearance of a serous cystadenocarcinoma vs mucinous cystadenocarcinoma?

Serous: bilateral, thin septations; mucinous: often unilateral with thick septations and internal debris.

What is the primary objective of the first trimester screening?

Assess risk for trisomies (21, 18) using NT and maternal serum markers (hCG, PAPP-A).

What is the primary cause of oligohydramnios in the second and third trimesters?

Renal anomalies or dysfunction (often bilateral), leading to reduced fetal urine output.

What is a key sign of placenta accreta on ultrasound?

Loss of a clear basal plate with placental lacunae and increased peripheral vascularity.

What ultrasound sign is associated with an open spina bifida (myelomeningocele)?

Spinal defects with associated Chiari II and hydros; may show lemon sign and banana sign.

What is the most common malignant germ cell tumor in younger patients?

Dysgerminoma (malignant germ cell tumor); often associated with elevated LDH and hCG in some cases.

What is the clinical significance of a chorioangioma?

Most common placental tumor; vascular mass near the placental insertion that may cause fetal anemia or hydrops.

What are the midline brain structures used as landmarks in fetal imaging?

CSP (cavum septi pellucidi), corpus callosum, and falx cerebri.

What is the role of folate in preventing neural tube defects?

Folate supplementation reduces risk of NTDs such as anencephaly and spina bifida.

What is the difference between open and occult spinal dysraphism (spina bifida occulta vs aperta)?

Occulta: closed, no herniation of spinal contents; Aperta: open with herniation (meningocele/myelomeningocele) and elevated AFP.

What ultrasound signs indicate a possible diaphragmatic hernia in the fetus?

Displacement of the heart with stomach/herniated organs on the opposite side; left‑sided Bochdalek hernia common.

What is the significance of twin peak (lambda) sign in twin gestations?

Indicates dichorionic diamniotic twinning (two placentas) in early pregnancy.

What does a single placental mass with two amniotic sacs suggest in twins?

Monochorionic diamniotic gestation; often requires close monitoring for TTTS.

What are the common signs of fetal hydrops on ultrasound?

Fluid in two fetal compartments (ascites, pleural effusion, pericardial effusion, skin edema).

What is the purpose of the NSR/RI index in Doppler assessment?

Resistive Index (RI) and Pulsatility Index (PI) quantify blood flow resistance; lower RI/PI indicates higher flow and vice versa.

What fetal signs are used to estimate gestational age in the first trimester?

CRL (crown-rump length) is the most reliable parameter for GA estimation in the first trimester.

What is the concept of a ‘stuck twin’ in TTTS?

Donor twin experiences severe oligohydramnios and appears physically pressed against the uterine wall.

What imaging feature is typical for an ovarian fibroma?

Solid, hypoechoic mass with poor through transmission; not estrogen-producing.

What is the term for a nonshadowing large region of fluid in the brain without a rim—used in hydrocephalus evaluation?

Hydranencephaly; brain tissue replaced by fluid with absence of cerebral hemispheres.

What is a corpus luteum cyst’s typical course in pregnancy?

Common physiologic cyst that becomes hormonally active and supports early pregnancy until placenta takes over.

What are the main T-signs of early pregnancy viability?

CRL growth with fetal cardiac activity; yolk sac presence; MSD progression.

What is the transducer choice for pelvic ultrasound in obese patients?

Lower frequency transducers for deeper penetration; higher frequency for superficial detail.