10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
These 10 free REI questions are organized by exam domain, so you can see how each part of the Reproductive Endocrinology & Infertility blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: Foundational Reproductive Endocrinology
Question 1
MRI obtained during an amenorrhea evaluation shows a 3.4-cm solid sellar mass. Serum prolactin is 54 ng/mL (reference interval 5-25 ng/mL). Pregnancy testing is negative; thyroid and renal function are normal, and the patient takes no prolactin-raising medication. Formal visual fields are normal. Before interpreting the modest prolactin elevation as stalk compression from a nonfunctioning tumor, the laboratory should:
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Correct answer: D - Repeat prolactin measurement using serially diluted samples
Question 2
During ovulation induction for hypothalamic GnRH deficiency, exogenous FSH produces follicular growth but little estradiol production. Adding low-dose hCG produces a substantial estradiol rise. Which ovarian action explains the response to the added LH activity?
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Correct answer: A - Theca cells supply androgen substrate for aromatization by FSH-stimulated granulosa cells
Domain 2: Reproductive Endocrine Function and Disease
Question 3
A 32-year-old with established primary ovarian insufficiency has troublesome hot flashes and low bone mineral density. Her uterus is intact. She has migraine with visual aura but no history of stroke or venous thromboembolism, and she does not smoke. She asks whether the aura means she must avoid estrogen replacement. What is the most appropriate long-term strategy?
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Correct answer: A - Transdermal estradiol with progestogen to protect the endometrium
Question 4
Seven months after increasing her running mileage and restricting food intake, a 26-year-old with previously regular cycles remains amenorrheic. Her BMI is 21 kg/m² after an 8-kg weight loss. Pregnancy testing is negative. Estradiol is 18 pg/mL, LH 0.8 IU/L, and FSH 4.1 IU/L; TSH, prolactin, testosterone, and DHEAS are normal. Ultrasound shows more than 20 small follicles in each ovary. The cause that best accounts for the endocrine pattern and time course is:
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Correct answer: B - Functional hypothalamic suppression from low energy availability
Domain 3: Conception and Pregnancy: Physiology and Pathology
Question 5
A patient with a confirmed unruptured tubal ectopic pregnancy is being followed under a single-dose methotrexate protocol. Her hCG concentrations are 2,200 mIU/mL on day 1, 2,600 on day 4, and 2,080 on day 7. At the day-7 visit she has no abdominal pain, stable vital signs, and only light spotting. Follow-up is reliable. Select the interpretation and plan supported by these findings.
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Correct answer: A - A 20% day-4-to-day-7 decline supports weekly hCG follow-up to a nonpregnant level
Domain 4: Fertility and Infertility
Question 6
On the planned trigger day of an IVF cycle, a 29-year-old has 27 follicles measuring 12-21 mm and a serum estradiol concentration of 6,100 pg/mL. She is receiving a GnRH antagonist, has normal pituitary function, and has no current symptoms of ovarian hyperstimulation syndrome. Several follicles are ready for final maturation. Which strategy best limits hyperstimulation risk while preserving the opportunity for oocyte retrieval?
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Correct answer: B - A GnRH-agonist-only trigger followed by freeze-all
Question 7
A couple has primary infertility. The male partner has sperm concentrations of 0.6 and 0.7 million/mL on two properly collected specimens. Both testes are small, FSH is elevated, semen volume is normal, and both vasa deferentia are palpable. There is no history suggesting ductal obstruction. Before assisted reproduction, which testing combination is specifically supported by the 2024 AUA/ASRM recommendations?
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Correct answer: D - Karyotype and Y-chromosome microdeletion analysis
Question 8
Two women are planning reciprocal IVF. Four good-quality, untested day-5 blastocysts were vitrified from oocytes retrieved from the 29-year-old partner. Her 42-year-old partner will carry the pregnancy and is preparing for her first frozen embryo transfer. They request two embryos because the gestating partner is over 40. How should age influence the recommendation?
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Correct answer: C - Prefer one blastocyst, using age at oocyte retrieval rather than the gestating partner's age
Domain 5: Anatomic Reproductive Disorders
Question 9
Two early pregnancy losses prompt assessment of uterine shape. Three-dimensional transvaginal ultrasound shows an internal fundal indentation 18 mm deep, measured from the bicornual line, with a leading-edge angle of 60 degrees. The external fundal indentation measures 4 mm, and there is one cervix. Using the ASRM Müllerian Anomalies Classification 2021, these measurements identify:
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Correct answer: C - A septate uterus
Domain 6: Reproductive Genetics
Question 10
One partner carries a balanced reciprocal translocation. Their embryos undergo PGT-SR using a validated copy-number assay without haplotyping or breakpoint-specific testing. A blastocyst has no detected chromosomal imbalance. The couple asks whether that embryo inherited the balanced translocation. Which conclusion is justified?
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Correct answer: C - It cannot distinguish a normal chromosome arrangement from a balanced translocation
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