Reproductive Endocrinology — MCQs

Reproductive Endocrinology Indian Medical PG Practice Questions and MCQs

Question 241: A 10-year-old girl presents with primary amenorrhea, widely spaced nipples, and streak-like gonads. What is the most likely diagnosis?

A. MRKH syndrome
B. Turner's syndrome (Correct Answer)
C. Swyer syndrome
D. Mixed gonadal dysgenesis

Explanation: ### Explanation **Correct Answer: B. Turner’s Syndrome** **Why it is correct:** Turner’s Syndrome (45,XO) is the most common cause of primary amenorrhea and hypergonadotropic hypogonadism. The clinical triad presented—**primary amenorrhea, widely spaced nipples (shield chest), and streak gonads**—is classic. Streak gonads occur because the absence of the second X chromosome leads to accelerated oocyte atresia, replacing functional ovarian tissue with fibrous stroma. This results in low estrogen and high FSH levels. **Why the other options are incorrect:** * **A. MRKH Syndrome:** Characterized by Müllerian agenesis (absent uterus and upper vagina). These patients have **normal ovaries** and normal secondary sexual characteristics (46,XX), unlike the streak gonads seen here. * **C. Swyer Syndrome:** This is 46,XY gonadal dysgenesis. While it presents with streak gonads and primary amenorrhea, patients are typically **tall** and do not exhibit the classic stigmata of Turner’s (like shield chest or short stature). * **D. Mixed Gonadal Dysgenesis:** Usually presents with a mosaic karyotype (45,X/46,XY) and **ambiguous genitalia**, which is not mentioned in this case. **High-Yield NEET-PG Pearls:** * **Most common karyotype:** 45,XO (Monosomy X). * **Short Stature:** The most consistent clinical finding (due to SHOX gene deficiency). * **Cardiac Association:** Bicuspid aortic valve (most common) and Coarctation of the aorta. * **Renal Association:** Horseshoe kidney. * **Diagnosis:** Gold standard is **Chromosomal Karyotyping**. * **Management:** Growth hormone for height; Estrogen/Progesterone for secondary sexual characteristics and bone health.

Question 242: What is the investigation of choice to differentiate Mullerian agenesis from testicular feminization syndrome in a case of primary amenorrhea?

A. Ultrasound (USG)
B. Laparoscopy
C. Karyotype (Correct Answer)
D. Hormonal assays

Explanation: In a patient presenting with primary amenorrhea, normal breast development, and an absent uterus, the two primary differentials are **Mullerian Agenesis (MRKH Syndrome)** and **Androgen Insensitivity Syndrome (Testicular Feminization)**. ### Why Karyotype is the Investigation of Choice The definitive differentiation between these two conditions lies in the genetic sex: * **Mullerian Agenesis:** The patient is a genotypic female (**46, XX**) with normal ovaries. The defect is a failure of Mullerian duct development. * **Androgen Insensitivity Syndrome:** The patient is a genotypic male (**46, XY**) with undescended testes. The defect is a mutation in the androgen receptor, leading to a female phenotype despite male genetics. ### Why Other Options are Incorrect * **Ultrasound (USG):** While USG can confirm the absence of a uterus and identify ovaries/testes, it is not definitive. Ovaries and undescended testes can sometimes look similar on imaging. * **Laparoscopy:** This is an invasive procedure. While it can visualize internal anatomy, it is no longer the "investigation of choice" when non-invasive genetic testing is available. * **Hormonal Assays:** Serum testosterone levels are high (male range) in AIS and low (female range) in MRKH. However, **Karyotyping** remains the gold standard for definitive diagnosis and management planning (e.g., timing of gonadectomy in AIS). ### High-Yield Clinical Pearls * **Pubic/Axillary Hair:** Present in MRKH (adrenarche is normal); **Absent or scanty** in AIS (due to androgen resistance). * **Gonads:** Ovaries are present in MRKH (normal ovulation/hormones); Testes are present in AIS (risk of malignancy/dysgerminoma). * **Testosterone Levels:** In AIS, testosterone is in the **normal male range**, but the body cannot respond to it.

Question 243: Which of the following is the most likely diagnosis in a 27-year-old obese woman presenting with oligomenorrhea, infertility, and hirsutism?

A. Polycystic ovarian syndrome (Correct Answer)
B. Endometriosis
C. Pelvic inflammatory disease
D. Turner's syndrome

Explanation: **Explanation:** The clinical presentation of **obesity, oligomenorrhea (infrequent periods), infertility, and hirsutism** is the classic triad of **Polycystic Ovarian Syndrome (PCOS)**. PCOS is the most common endocrine disorder in women of reproductive age. The underlying pathophysiology involves insulin resistance and hyperandrogenism, which disrupts the hypothalamic-pituitary-ovarian axis, leading to chronic anovulation and the characteristic clinical features. **Why the other options are incorrect:** * **Endometriosis:** Typically presents with the "3 Ds": Dysmenorrhea, Dyspareunia, and Dyschezia. While it causes infertility, it does not cause hirsutism or obesity. * **Pelvic Inflammatory Disease (PID):** An infectious process presenting with pelvic pain, vaginal discharge, and fever. It can lead to tubal factor infertility but is not associated with endocrine symptoms like hirsutism. * **Turner’s Syndrome (45, XO):** Characterized by primary amenorrhea (not oligomenorrhea), short stature, and streak ovaries. These patients have low estrogen and high gonadotropins, not hyperandrogenism. **High-Yield Clinical Pearls for NEET-PG:** * **Rotterdam Criteria:** Diagnosis requires 2 out of 3: (1) Oligo/Anovulation, (2) Clinical/Biochemical Hyperandrogenism, (3) Polycystic ovaries on Ultrasound ("String of pearls" appearance). * **LH:FSH Ratio:** Often increased to **3:1** (though no longer a primary diagnostic criterion). * **Gold Standard Treatment for Infertility:** Letrozole (Aromatase inhibitor) is now the first-line drug for ovulation induction in PCOS, surpassing Clomiphene citrate. * **Metabolic Risk:** Patients are at increased risk for Type 2 Diabetes and Endometrial Hyperplasia/Carcinoma due to unopposed estrogen.

Question 244: What are the levels of progesterone indicating an unruptured follicle and a ruptured intrauterine pregnancy?

A. 5 ng/ml; 20 ng/ml (Correct Answer)
B. 10 ng/ml; 20 ng/ml
C. 5 ng/ml; 50 ng/ml
D. 10 ng/ml; 50 ng/ml

Explanation: **Explanation:** Serum progesterone is a critical biochemical marker used to assess the functionality of the corpus luteum and the viability of early pregnancy. 1. **Unruptured Follicle (Anovulation):** In a normal menstrual cycle, progesterone levels remain low (<2 ng/ml) during the follicular phase. Following ovulation, the corpus luteum produces progesterone. A level **<5 ng/ml** is generally suggestive of an unruptured follicle or anovulatory cycle, whereas a level **>5 ng/ml** is considered reliable evidence that ovulation has occurred. 2. **Intrauterine Pregnancy (IUP):** During early pregnancy, the corpus luteum (stimulated by hCG) produces significant amounts of progesterone to maintain the decidua. A serum progesterone level **>20–25 ng/ml** is highly suggestive of a healthy, viable intrauterine pregnancy. Conversely, levels <5 ng/ml are strongly associated with non-viable pregnancies (either an impending miscarriage or an ectopic pregnancy). **Analysis of Incorrect Options:** * **Options B, C, and D:** These options use thresholds (10 ng/ml or 50 ng/ml) that do not align with standard clinical diagnostic criteria. While 10 ng/ml is sometimes used as a marker for adequate luteal phase support, 5 ng/ml remains the classic "cutoff" for confirming ovulation in exams. 50 ng/ml is unnecessarily high and not used as a diagnostic baseline for confirming IUP. **NEET-PG High-Yield Pearls:** * **Ovulation Confirmation:** The best time to measure progesterone to confirm ovulation is the **mid-luteal phase** (Day 21 of a 28-day cycle). * **Ectopic Pregnancy:** Progesterone levels between 5–20 ng/ml represent a "grey zone" where an ectopic pregnancy cannot be ruled out; however, a level **<5 ng/ml** almost certainly indicates a non-viable pregnancy (regardless of location). * **Source:** In the first 7–10 weeks of gestation, the **corpus luteum** is the primary source of progesterone; thereafter, the **placenta** takes over (Luteal-Placental shift).

Question 245: A 16-year-old female presents with primary amenorrhea. Examination shows a short, blind vagina with an absent uterus. What is the next investigation of choice?

A. Karyotyping (Correct Answer)
B. Intravenous pyelogram (IVP)
C. Gonadotropin levels
D. Serum prolactin

Explanation: **Explanation:** The clinical presentation of primary amenorrhea with a **blind vagina and absent uterus** points toward two primary differential diagnoses: **Müllerian Agenesis (Mayer-Rokitansky-Küster-Hauser syndrome)** and **Complete Androgen Insensitivity Syndrome (CAIS)**. 1. **Why Karyotyping is the Correct Answer:** Karyotyping is the definitive investigation to differentiate between these two conditions. * In **MRKH**, the karyotype is **46,XX** (female), ovaries are functional, and secondary sexual characteristics are normal. * In **CAIS**, the karyotype is **46,XY** (male). The patient has undescended testes which must be surgically removed after puberty due to the high risk of malignancy (gonadoblastoma/dysgerminoma). Therefore, determining the genetic sex is the crucial next step for management. 2. **Why Other Options are Incorrect:** * **Intravenous Pyelogram (IVP):** While renal anomalies are common in MRKH (up to 30-40%), an IVP or Renal USG is performed *after* the diagnosis is established, not as the initial differentiating tool. * **Gonadotropin levels (FSH/LH):** These are typically normal in both MRKH and CAIS (as both have functioning gonads—ovaries and testes respectively). They are more useful in diagnosing premature ovarian failure or central causes of amenorrhea. * **Serum Prolactin:** This is used to rule out hyperprolactinemia, which presents with secondary amenorrhea or primary amenorrhea *with* a present uterus. **High-Yield Clinical Pearls for NEET-PG:** * **MRKH:** 46,XX; Normal female testosterone levels; Ovaries present; Associated with renal/skeletal (VACTERL) anomalies. * **CAIS:** 46,XY; Male testosterone levels (but body is insensitive); Absent/scant pubic and axillary hair; Testes present (usually inguinal). * **Initial Investigation:** Ultrasound (to confirm absent uterus). * **Next/Confirmatory Investigation:** Karyotyping.

Question 246: Increased capillary permeability in Ovarian Hyperstimulation Syndrome (OHSS) is due to all except:

A. Vascular endothelial growth factor
B. Angiotensin II
C. Oestrogen
D. Inhibin (Correct Answer)

Explanation: **Explanation:** Ovarian Hyperstimulation Syndrome (OHSS) is a serious iatrogenic complication of ovulation induction, characterized by a massive shift of fluid from the intravascular space to the extravascular space (third-spacing) due to **increased capillary permeability**. **Why Inhibin is the correct answer:** While Inhibin levels (specifically Inhibin A and B) are often elevated in OHSS as they reflect the high number of developing follicles, they are **markers** of ovarian response rather than causative agents of vascular permeability. Inhibin does not possess vasoactive properties and does not contribute to the pathophysiology of fluid leakage. **Analysis of other options:** * **Vascular Endothelial Growth Factor (VEGF):** This is the **primary mediator** of OHSS. Triggering ovulation with hCG leads to an over-expression of VEGF and its receptor (VEGFR2) in the ovaries, which directly increases vascular permeability. * **Angiotensin II:** The ovarian Renin-Angiotensin System (RAS) is highly active in OHSS. Increased levels of Angiotensin II promote angiogenesis and increase capillary permeability. * **Oestrogen:** High serum estradiol levels are a hallmark of OHSS. While not the direct cause of leakage, oestrogen acts as a precursor and modulator that correlates with the severity of the syndrome and enhances the effects of other vasoactive substances. **High-Yield Clinical Pearls for NEET-PG:** * **Primary Trigger:** Administration of **hCG** (due to its long half-life and structural similarity to LH). * **Key Pathophysiology:** Increased capillary permeability $\rightarrow$ Ascites, Pleural effusion, Hemoconcentration, and Thromboembolism. * **Prevention:** Use of **GnRH agonists** instead of hCG for the "trigger" in high-risk patients (GnRH antagonist cycles) and "coasting" (withholding gonadotropins). * **Management:** Fluid resuscitation (crystalloids/albumin) and thromboprophylaxis; avoid diuretics in the early phase as they worsen hemoconcentration.

Question 247: In a girl with sexual infantilism and defective smell sensation, which of the following is the likely diagnosis transmitted by the sex chromosome?

A. Kallman's syndrome (Correct Answer)
B. Rokitansky-Kuster-Hauser syndrome
C. Androgen insensitivity syndrome
D. McCune-Albright syndrome

Explanation: ### Explanation **Kallmann’s Syndrome** is the correct diagnosis based on the classic clinical dyad of **hypogonadotropic hypogonadism** (leading to sexual infantilism/delayed puberty) and **anosmia or hyposmia** (defective smell). 1. **Why it is correct:** The condition results from the failure of GnRH-secreting neurons and olfactory neurons to migrate from the olfactory placode to the hypothalamus. While it can be autosomal dominant or recessive, the most classic form (KAL1 gene mutation) is **X-linked recessive**, satisfying the "transmitted by sex chromosome" criteria in the question. 2. **Why the others are incorrect:** * **Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome:** Characterized by Müllerian agenesis (absent uterus/upper vagina). These patients have normal ovaries, normal secondary sexual characteristics (not infantilism), and a normal sense of smell. * **Androgen Insensitivity Syndrome (AIS):** These are genotypic males (46,XY) with a female phenotype. They have breast development (due to peripheral aromatization) but absent pubic hair. They do not have anosmia. * **McCune-Albright Syndrome:** Presents with a triad of **precocious puberty** (not infantilism), café-au-lait spots, and polyostotic fibrous dysplasia. ### NEET-PG High-Yield Pearls * **Gold Standard Diagnosis:** MRI of the brain (shows absent or hypoplastic olfactory bulbs). * **Hormonal Profile:** Low GnRH → Low FSH/LH → Low Estrogen (Hypogonadotropic Hypogonadism). * **Associated Features:** Color blindness, cleft lip/palate, and renal agenesis (especially in the X-linked form). * **Treatment:** Pulsatile GnRH therapy is used to induce ovulation/fertility; HRT is used for the development of secondary sexual characteristics.

Question 248: What is the drug of choice for Polycystic Ovarian Disease?

A. Metformin
B. Estrogen
C. Estrogen and progesterone combination pill (Correct Answer)
D. Dopamine antagonist

Explanation: **Explanation:** The primary goal in managing Polycystic Ovarian Disease (PCOD/PCOS) is to address the underlying hormonal imbalance—specifically hyperandrogenism and chronic anovulation. **Why Option C is Correct:** The **Combined Oral Contraceptive Pill (COCP)**, containing both estrogen and progesterone, is the **first-line medical management** for PCOS. 1. **Estrogen component:** Increases Sex Hormone Binding Globulin (SHBG) levels, which binds free testosterone, thereby reducing hirsutism and acne. It also suppresses LH secretion. 2. **Progesterone component:** Protects the endometrium from "unopposed estrogen" (caused by anovulation), thereby preventing endometrial hyperplasia and regulating the menstrual cycle. **Why other options are incorrect:** * **A. Metformin:** While used to treat insulin resistance in PCOS, it is considered a second-line agent or an adjuvant. It is primarily used when the patient has glucose intolerance or as an ovulation induction agent in specific cases, but it is not the "drug of choice" for overall symptom management. * **B. Estrogen alone:** Giving estrogen without progesterone in PCOS is contraindicated as it significantly increases the risk of endometrial carcinoma due to the already thickened endometrial lining. * **D. Dopamine antagonist:** These drugs (like Metoclopramide) increase prolactin levels and would worsen menstrual irregularities. Dopamine *agonists* (like Cabergoline) are used for Hyperprolactinemia, not PCOS. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of choice for Ovulation Induction in PCOS:** Letrozole (Aromatase inhibitor) is now preferred over Clomiphene Citrate. * **Rotterdam Criteria:** Diagnosis requires 2 out of 3: (1) Clinical/biochemical hyperandrogenism, (2) Oligo/anovulation, (3) Polycystic ovaries on ultrasound ("String of pearls" appearance). * **LH:FSH Ratio:** Classically elevated to >2:1 or 3:1 in PCOS patients.

Question 249: A 20-year-old female presents for an infertility workup. She has never had a menstrual period. She is short with a broad chest, webbed neck, and low-set ears. It is demonstrated that she has an abnormal karyotype. What is the cause of the woman's abnormal karyotype?

A. Maternal nondisjunction
B. Paternal nondisjunction
C. Both maternal and paternal nondisjunction
D. Either maternal or paternal nondisjunction (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Either maternal or paternal nondisjunction** The clinical presentation (short stature, broad chest, webbed neck, and primary amenorrhea) is classic for **Turner Syndrome**, which most commonly results from a **45,X** karyotype. This condition occurs due to the loss of one X chromosome (monosomy X). **Why the correct answer is right:** The loss of a sex chromosome typically occurs due to **nondisjunction**—the failure of homologous chromosomes or sister chromatids to separate properly during meiosis. In Turner Syndrome, the single X chromosome present is maternal in approximately 70-80% of cases (meaning the paternal sperm was missing the sex chromosome). However, the error can also occur during maternal oogenesis, leading to an egg lacking an X chromosome. Therefore, the missing chromosome can be of either maternal or paternal origin. **Why incorrect options are wrong:** * **A & B:** These are partially correct but incomplete. Attributing the error to only one parent ignores the established genetic evidence that nondisjunction can occur in either the sperm or the egg. * **C:** This implies that both parents must have a nondisjunction event simultaneously for the condition to occur, which is incorrect. Turner Syndrome requires only one gamete to be aneuploid (nullisomic for a sex chromosome). **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Primary Amenorrhea:** Turner Syndrome (45,X). * **Karyotype:** 45,X is the most common (50%), followed by mosaicism (e.g., 45,X/46,XX) and structural abnormalities (e.g., Isochromosome Xq). * **Gonads:** Characterized by **"Streak Ovaries"** due to accelerated germ cell atresia; estrogen levels are low, and FSH/LH levels are high (Hypergonadotropic Hypogonadism). * **Associated Findings:** Bicuspid aortic valve (most common cardiac anomaly), Coarctation of the aorta, and Horseshoe kidney. * **Management:** Growth hormone for height; Estrogen/Progesterone for secondary sexual characteristics and bone health.

Question 250: Increased LH:FSH ratio is found in which of the following conditions?

A. Premature menopause
B. Polycystic ovary syndrome
C. Turner's syndrome
D. Polycystic ovary syndrome (Correct Answer)

Explanation: **Explanation:** In **Polycystic Ovary Syndrome (PCOS)**, the hallmark endocrine abnormality is an **increased LH:FSH ratio**, typically >2:1 or 3:1. This occurs due to an increased frequency and amplitude of GnRH pulses from the hypothalamus, which preferentially stimulates the anterior pituitary to produce Luteinizing Hormone (LH) over Follicle Stimulating Hormone (FSH). High LH levels stimulate the ovarian theca cells to produce excess androgens, while relatively low FSH levels lead to poor follicular maturation and the characteristic "necklace appearance" of multiple small follicles on ultrasound. **Analysis of Incorrect Options:** * **Premature Menopause (Premature Ovarian Failure):** This is a state of hypergonadotropic hypogonadism. Due to primary ovarian failure, there is a loss of negative feedback from estrogen and inhibin. Consequently, **both FSH and LH are elevated**, but **FSH rises significantly more than LH** (FSH >40 mIU/mL) because FSH has a slower clearance rate. * **Turner’s Syndrome (45, XO):** This involves streak ovaries and primary ovarian failure. Similar to menopause, it presents with **elevated FSH and LH**, with FSH being the predominant hormone elevated due to the lack of follicular activity and inhibin. **NEET-PG High-Yield Pearls:** * **Gold Standard for PCOS Diagnosis:** Rotterdam Criteria (requires 2 out of 3: Hyperandrogenism, Ovulatory dysfunction, and Polycystic ovaries on USG). * **Insulin Resistance:** A key driver in PCOS; it decreases Sex Hormone Binding Globulin (SHBG), further increasing free testosterone levels. * **FSH in Menopause:** FSH is a more sensitive marker for ovarian failure/menopause than LH. * **LH Surge:** In a normal cycle, the LH surge triggers ovulation; in PCOS, the "tonic" elevation of LH prevents this surge, leading to chronic anovulation.

Practice by Chapter

Hypothalamic-Pituitary-Ovarian Axis

Practice Questions

Disorders of Puberty

Practice Questions

Hirsutism and Virilization

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Primary Ovarian Insufficiency

Practice Questions

Hyperprolactinemia

Practice Questions

Hyperandrogenism

Practice Questions

Metabolic Dysfunction in PCOS

Practice Questions

Neuroendocrine Disorders and Reproduction

Practice Questions

Hormonal Evaluation and Testing

Practice Questions

Ovulation Induction

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