Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy Indian Medical PG Practice Questions and MCQs

Question 171: A 16-year-old girl has not yet reached menarche. She has normal secondary sex characteristics, and visual inspection of her external genitalia is unremarkable. The patient is given progesterone and has withdrawal bleeding a few days later. This patient most likely has:

A. Primary ovarian disease
B. Turner syndrome
C. A destructive hypothalamic disorder
D. A constitutional delay in puberty (Correct Answer)

Explanation: **Explanation:** The core concept tested here is the **Progesterone Challenge Test (PCT)**. A positive withdrawal bleed indicates two things: 1. The **HPO axis** is functional enough to produce endogenous estrogen. 2. The **outflow tract** (uterus, cervix, and vagina) is patent and responsive. **Why "Constitutional Delay in Puberty" is correct:** In constitutional delay, the patient has normal secondary sexual characteristics (indicating prior estrogen exposure) and a functional anatomy. The positive withdrawal bleed confirms that the ovaries are producing enough estrogen to prime the endometrium, but the hypothalamic-pituitary-ovarian (HPO) axis has not yet matured enough to trigger spontaneous ovulation. It is a diagnosis of exclusion in a healthy girl with delayed menarche but normal development. **Why the other options are incorrect:** * **A & B (Primary Ovarian Disease/Turner Syndrome):** These conditions are characterized by **Hypergonadotropic Hypogonadism**. The ovaries fail to produce estrogen; therefore, the endometrium is not primed. These patients would have a **negative** progesterone challenge test. * **C (Destructive Hypothalamic Disorder):** Severe hypothalamic or pituitary lesions result in **Hypogonadotropic Hypogonadism**. Low GnRH/FSH leads to minimal estrogen production, resulting in a **negative** progesterone challenge test. **NEET-PG Clinical Pearls:** * **Positive PCT:** Requires an endometrial thickness of $\geq$ 4–5 mm and serum estradiol levels $>40$ pg/mL. * **Negative PCT:** Next step is the **Estrogen-Progesterone Challenge Test**. If bleeding occurs now, the problem is the HPO axis (low estrogen). If no bleeding occurs, the problem is the **outflow tract** (e.g., Asherman syndrome or Mullerian agenesis). * **Most common cause of Primary Amenorrhea with normal secondary sex characteristics:** Mullerian Agenesis (MRKH Syndrome) — but they would have a **negative** PCT due to the absence of a uterus.

Question 172: Precocious sexual development is characterized by breast and pubic hair growth before what age?

A. 8 years (Correct Answer)
B. 9 years
C. 10 years
D. 11 years

Explanation: **Explanation:** Precocious puberty is defined as the onset of secondary sexual characteristics (thelarche or pubarche) at an age that is more than 2.5 standard deviations below the mean for the population. In females, the established clinical cutoff for precocious development is **8 years**. **1. Why 8 years is correct:** In girls, the first sign of puberty is typically thelarche (breast budding), followed by pubarche (pubic hair) and menarche. If these changes occur before the age of 8, it indicates premature activation of the Hypothalamic-Pituitary-Gonadal (HPG) axis (Central Precocious Puberty) or autonomous peripheral production of sex steroids (Peripheral Precocious Puberty). **2. Why the other options are incorrect:** * **9 years:** This is the age cutoff for precocious puberty in **males** (development of secondary sexual characteristics before age 9). * **10 and 11 years:** These ages fall within the normal physiological range for the onset of puberty in females. The average age for thelarche is approximately 10–10.5 years, and menarche typically occurs around 12–12.5 years. **NEET-PG High-Yield Pearls:** * **Sequence of Puberty (Girls):** Thelarche (Breast) → Pubarche (Hair) → Growth Spurt → Menarche (Bleeding). Remember the mnemonic: **"T-P-G-M"**. * **Central vs. Peripheral:** Central precocious puberty is "GnRH-dependent" and is most commonly **idiopathic** in girls. Peripheral is "GnRH-independent" (e.g., McCune-Albright Syndrome, Granulosa cell tumor). * **Investigation of Choice:** Bone age assessment (X-ray of the left hand/wrist) is the initial step to evaluate skeletal maturation. * **Treatment:** GnRH analogues (e.g., Leuprolide) are the gold standard for Central Precocious Puberty to prevent premature epiphyseal fusion and short adult stature.

Question 173: The risk of thromboembolism increases in pregnancy because:

A. Viscosity of blood increases
B. Increased hepatic production of clotting factors (Correct Answer)
C. Increased antithrombin III levels
D. Increased progesterone levels

Explanation: Pregnancy is a **hypercoagulable state** designed to protect the mother from hemorrhage during delivery. This physiological adaptation involves a shift in the balance between procoagulant and anticoagulant factors. ### **Explanation of the Correct Answer** **B. Increased hepatic production of clotting factors:** Estrogen stimulates the liver to increase the synthesis of several coagulation factors. Specifically, there is a significant rise in **Factors I (Fibrinogen), VII, VIII, IX, and X**. Fibrinogen levels increase by nearly 50%, reaching up to 400–600 mg/dL. This increase in procoagulant factors, combined with a decrease in natural anticoagulants (like Protein S) and impaired fibrinolysis, creates a high risk for thromboembolism. ### **Why Other Options are Incorrect** * **A. Viscosity of blood increases:** In pregnancy, blood viscosity actually **decreases**. This is because the plasma volume increases (approx. 45-50%) more than the red cell mass (approx. 20-30%), leading to hemodilution (physiological anemia). * **C. Increased antithrombin III levels:** Antithrombin III is a natural anticoagulant. In pregnancy, its levels remain **unchanged or slightly decrease**, which contributes to the hypercoagulable state rather than preventing it. * **D. Increased progesterone levels:** While progesterone causes venous stasis due to smooth muscle relaxation (vasodilation), the primary biochemical driver for the increase in clotting factors is **Estrogen**. ### **High-Yield Clinical Pearls for NEET-PG** * **Virchow’s Triad in Pregnancy:** 1. Hypercoagulability (↑ Factors), 2. Venous Stasis (Progesterone + IVC compression), 3. Endothelial injury (during delivery). * **Most common site for DVT in pregnancy:** Left iliofemoral vein (due to May-Thurner syndrome-like compression of the left common iliac vein by the right common iliac artery). * **Factor XI and XIII:** These are the only factors that actually **decrease** during pregnancy. * **Postpartum Period:** The risk of thromboembolism is highest in the immediate postpartum period (first 6 weeks).

Question 174: What are the normal fasting plasma glucose levels during a 75g Glucose Tolerance Test (GTT) in pregnancy?

A. <=105 mg/dL
B. <92 mg/dL (Correct Answer)
C. <=140 mg/dL
D. <=120 mg/dL

Explanation: The correct answer is **B. <92 mg/dL**. ### **Explanation** The diagnosis of Gestational Diabetes Mellitus (GDM) has evolved significantly. According to the **IADPSG (International Association of Diabetes and Pregnancy Study Groups)** and **WHO** criteria, a one-step 75g Oral Glucose Tolerance Test (OGTT) is used. In pregnancy, fasting glucose levels are naturally lower than in non-pregnant individuals due to continuous fetal glucose consumption and increased maternal volume of distribution. The diagnostic thresholds for a 75g OGTT are: * **Fasting:** <92 mg/dL * **1-hour:** <180 mg/dL * **2-hour:** <153 mg/dL * *Note: If any one value is met or exceeded, GDM is diagnosed.* ### **Analysis of Incorrect Options** * **Option A (≤105 mg/dL):** This was the older fasting threshold used in the **NDDG (National Diabetes Data Group)** criteria for the 100g 3-hour OGTT. It is no longer the standard for the 75g test. * **Option C (≤140 mg/dL):** This is the standard threshold for a **1-hour 50g Glucose Challenge Test (GCT)** used in two-step screening. It is not a fasting value. * **Option D (≤120 mg/dL):** This is often the target for **2-hour postprandial** glucose monitoring in managed GDM patients, not a diagnostic fasting threshold. ### **High-Yield Clinical Pearls for NEET-PG** 1. **DIPSI Criteria:** In India, the DIPSI (Diabetes in Pregnancy Study Group India) recommends a single-step 75g GTT regardless of the last meal. A 2-hour value **≥140 mg/dL** is diagnostic of GDM. 2. **Hormonal Basis:** Human Placental Lactogen (hPL) is the primary hormone responsible for insulin resistance in pregnancy, peaking in the third trimester. 3. **Best Time to Screen:** Routine screening is performed between **24–28 weeks** of gestation.

Question 175: What is the optimal value of glycosylated hemoglobin in a woman with diabetes preconceptionally?

A. <6.5% (Correct Answer)
B. <7.5%
C. <8.1%
D. <9%

Explanation: **Explanation:** The goal of preconceptional counseling in diabetic women is to achieve euglycemia before organogenesis begins (which starts around the 3rd to 5th week of gestation). **1. Why <6.5% is correct:** The risk of major congenital malformations (such as sacral agenesis, neural tube defects, and cardiac anomalies) is directly proportional to the maternal HbA1c levels during the first trimester. An **HbA1c <6.5%** is the internationally recognized target (ADA and ACOG guidelines) because it minimizes the risk of embryopathy to a level comparable to the non-diabetic population. Achieving this value ensures that the metabolic environment is stable before the patient conceives. **2. Why other options are incorrect:** * **<7.5% and <8.1%:** While these levels might be acceptable for non-pregnant adults to prevent long-term microvascular complications, they are associated with a significantly higher risk of spontaneous abortion and congenital anomalies in the context of pregnancy. * **<9%:** An HbA1c >9% is associated with a very high risk (up to 20-25%) of major malformations. In clinical practice, an HbA1c >10% is often considered a relative contraindication to pregnancy until better control is achieved. **High-Yield Clinical Pearls for NEET-PG:** * **Most common malformation:** Cardiac anomalies (specifically Ventricular Septal Defects). * **Most specific malformation:** Caudal Regression Syndrome (Sacral Agenesis). * **HbA1c Target during pregnancy:** Ideally <6.0% (if achievable without significant hypoglycemia). * **Folic Acid:** Diabetic women should take a higher dose (5 mg/day) pre-conceptionally to reduce the risk of Neural Tube Defects.

Question 176: Which of the following is NOT a normal physiological finding in pregnancy?

A. Dyspnea
B. Systolic murmur
C. Diastolic murmur (Correct Answer)
D. Exercise intolerance

Explanation: In pregnancy, the cardiovascular system undergoes significant remodeling to meet increased metabolic demands. Understanding the distinction between physiological adaptations and pathological signs is crucial for NEET-PG. ### **Why Diastolic Murmur is the Correct Answer** A **diastolic murmur is always pathological** in pregnancy. While pregnancy is a hyperdynamic state characterized by increased cardiac output (up to 50%) and stroke volume, these changes typically manifest as systolic flow murmurs. A diastolic murmur suggests underlying structural heart disease, such as mitral stenosis or aortic regurgitation, and warrants immediate investigation with an echocardiogram. ### **Analysis of Incorrect Options** * **A. Dyspnea:** Physiological dyspnea occurs in about 75% of pregnant women. It is primarily due to increased progesterone levels, which increase the sensitivity of the respiratory center to $CO_2$, leading to "hyperventilation of pregnancy." * **B. Systolic Murmur:** Up to 90% of pregnant women develop a **Grade I or II midsystolic flow murmur**. This is caused by decreased blood viscosity (hemodilution) and increased flow velocity across the pulmonary and aortic valves. * **D. Exercise Intolerance:** This is a normal finding due to the increased mechanical load of the gravid uterus, increased basal metabolic rate, and the physiological shift in the center of gravity. ### **High-Yield Clinical Pearls for NEET-PG** * **Heart Sounds:** An exaggerated S1 split and a physiological S3 are common/normal in pregnancy. * **ECG Changes:** Left axis deviation is common as the diaphragm elevates and displaces the heart upward and to the left. * **Blood Pressure:** Diastolic BP decreases in the first and second trimesters (nadir at 24 weeks) due to decreased Systemic Vascular Resistance (SVR). * **Rule of Thumb:** Systolic = Flow (Normal); Diastolic = Disease (Abnormal).

Question 177: What is the most common effect of congenital adrenal hyperplasia?

A. Female pseudohermaphroditism (Correct Answer)
B. Male pseudohermaphroditism
C. True hermaphroditism
D. Gonadal dysgenesis

Explanation: **Explanation:** Congenital Adrenal Hyperplasia (CAH) is a group of autosomal recessive disorders characterized by a deficiency in enzymes required for cortisol synthesis, most commonly **21-hydroxylase deficiency** (90-95% of cases). **Why the correct answer is right:** In CAH, the lack of cortisol leads to a compensatory increase in Adrenocorticotropic Hormone (ACTH) via negative feedback. This causes adrenal hyperplasia and shunts steroid precursors toward the androgen pathway. In a genetically female fetus (46,XX), these high levels of circulating androgens during the critical period of sexual differentiation (8–12 weeks) cause virilization of the external genitalia (clitoral hypertrophy, labial fusion). Since the internal female organs (ovaries, uterus, tubes) develop normally from the Müllerian ducts (as there is no Anti-Müllerian Hormone), the result is **Female Pseudohermaphroditism** (genotypic female with masculinized external genitalia). **Why incorrect options are wrong:** * **Male Pseudohermaphroditism:** This refers to a 46,XY individual with feminized external genitalia. CAH in males typically causes precocious puberty or salt-wasting, not feminization. * **True Hermaphroditism:** This requires the presence of both ovarian and testicular tissue in the same individual, usually due to chimerism or mosaicism, not enzymatic defects. * **Gonadal Dysgenesis:** This involves the failure of gonads to develop (e.g., Turner Syndrome 45,X), leading to "streak gonads" rather than virilization. **High-Yield Clinical Pearls for NEET-PG:** * **Most common enzyme deficiency:** 21-hydroxylase (leads to increased **17-hydroxyprogesterone**). * **Most common cause of ambiguous genitalia** in a newborn is CAH. * **Salt-wasting type:** Occurs in severe 21-hydroxylase deficiency due to aldosterone lack (Hyponatremia, Hyperkalemia). * **Treatment:** Glucocorticoids (to suppress ACTH) and Mineralocorticoids (if salt-wasting).

Question 178: All of the following drugs can be given to a mother with lupus after 35th week of gestation, except?

A. Chloroquine
B. Methotrexate (Correct Answer)
C. Sulphadiazine / Sulphasalazine
D. Prednisolone

Explanation: **Explanation:** The correct answer is **Methotrexate (Option B)**. Methotrexate is a potent folic acid antagonist and is strictly **contraindicated** throughout pregnancy (FDA Category X). While its teratogenic effects (fetal hydantoin-like syndrome, cranial anomalies) are most concerning in the first trimester, it remains contraindicated in the third trimester due to its potential for neonatal myelosuppression and hepatotoxicity. **Analysis of Options:** * **Chloroquine (Option A):** Antimalarials (Hydroxychloroquine/Chloroquine) are considered the cornerstone of SLE management in pregnancy. They are safe and essential to prevent lupus flares and reduce the risk of neonatal heart block. * **Sulphadiazine / Sulphasalazine (Option C):** These are considered safe in pregnancy. While sulfonamides are generally avoided near term due to the theoretical risk of neonatal kernicterus (by displacing bilirubin from albumin), Sulphasalazine is frequently used in stable autoimmune patients and is not strictly contraindicated like Methotrexate. * **Prednisolone (Option D):** This is the steroid of choice for maternal indications (like SLE flares). It is metabolized by the placental enzyme **11-beta-hydroxysteroid dehydrogenase**, ensuring that less than 10% of the drug reaches the fetus, thus minimizing fetal side effects. **NEET-PG High-Yield Pearls:** * **Drug of Choice for SLE in Pregnancy:** Hydroxychloroquine (reduces flares). * **Steroids in Pregnancy:** Prednisolone is used for maternal SLE; **Betamethasone/Dexamethasone** are used for fetal lung maturity (as they cross the placenta). * **Lupus & Neonatal Heart Block:** Associated with Anti-Ro (SSA) and Anti-La (SSB) antibodies. * **Safe Immunosuppressants in Pregnancy:** Azathioprine, Cyclosporine, and Tacrolimus. * **Contraindicated in SLE Pregnancy:** Methotrexate, Mycophenolate Mofetil (MMF), and Cyclophosphamide.

Question 179: A pregnant female is taking carbimazole. Which of the following is NOT seen in the neonate?

A. Choanal atresia
B. Scalp defects
C. Cleft lip/palate (Correct Answer)
D. Fetal goiter

Explanation: **Explanation:** The question tests your knowledge of the teratogenic effects of anti-thyroid drugs. Carbimazole (a prodrug of Methimazole) is associated with a specific pattern of malformations known as **Methimazole Embryopathy**. **Why Cleft Lip/Palate is the correct answer:** Cleft lip and palate are **not** part of the classic Methimazole Embryopathy. While they are common congenital anomalies, they are not specifically linked to carbimazole exposure. In contrast, Propylthiouracil (PTU) is generally preferred in the first trimester because it has a lower risk of causing the specific structural defects associated with carbimazole. **Analysis of Incorrect Options:** * **Choanal Atresia (A) & Scalp Defects (B):** These are hallmark features of Methimazole Embryopathy. Scalp defects specifically refer to **Aplasia Cutis Congenita** (localized absence of skin, usually on the scalp). Other features include esophageal atresia and facial dysmorphism. * **Fetal Goiter (D):** Both Carbimazole and PTU cross the placenta and can inhibit the fetal thyroid gland. This leads to an increase in fetal TSH, resulting in fetal goiter and potential hypothyroidism. **High-Yield NEET-PG Pearls:** 1. **Drug of Choice:** PTU is preferred in the **1st trimester** (due to carbimazole teratogenicity). Carbimazole/Methimazole is preferred in the **2nd and 3rd trimesters** (due to PTU-induced maternal hepatotoxicity). 2. **Aplasia Cutis:** If you see "scalp defect" and "anti-thyroid drug" in a clinical stem, think Carbimazole/Methimazole. 3. **Mechanism:** Both drugs act by inhibiting the enzyme **Thyroid Peroxidase**, blocking the organification of iodine.

Question 180: Insulin resistance in pregnancy is due to which of the following hormones?

A. Estrogen
B. Progesterone
C. Human Placental Lactogen (HPL)
D. All of the above (Correct Answer)

Explanation: **Explanation:** Pregnancy is a naturally "diabetogenic state" characterized by progressive insulin resistance, primarily during the second and third trimesters. This physiological adaptation ensures a continuous supply of glucose to the fetus by decreasing maternal glucose utilization. **Why "All of the Above" is correct:** Insulin resistance is a multifactorial process driven by several placental hormones: * **Human Placental Lactogen (hPL):** Also known as Human Chorionic Somatomammotropin (hCS), this is the **most potent** antagonist to insulin. It promotes lipolysis and inhibits peripheral glucose uptake. * **Progesterone and Estrogen:** These steroid hormones interfere with the insulin signaling pathway at the post-receptor level, further decreasing insulin sensitivity. * **Other factors:** Placental growth hormone, cortisol, and inflammatory cytokines (TNF-alpha) also contribute to this resistance. **Analysis of Options:** * **Option A & B:** While Estrogen and Progesterone contribute significantly, selecting either one alone would be incomplete, as they work synergistically with hPL. * **Option C:** hPL is the primary driver, but the presence of other diabetogenic hormones makes "All of the above" the most accurate clinical answer. **NEET-PG High-Yield Pearls:** 1. **Peak Resistance:** Insulin resistance peaks in the **third trimester** (coinciding with maximum placental mass). 2. **The "Diabetogenic" Hormone:** If the question asks for the *single most important* hormone responsible, the answer is **hPL**. 3. **Fetal Fuel:** Glucose crosses the placenta via **facilitated diffusion (GLUT-1)**, whereas insulin does **not** cross the placenta. 4. **Clinical Correlation:** Gestational Diabetes Mellitus (GDM) occurs when the maternal pancreas cannot increase insulin secretion (usually 2–3 fold) to overcome this hormonal resistance.

Practice by Chapter

Endocrine Changes in Normal Pregnancy

Practice Questions

Thyroid Disorders in Pregnancy

Practice Questions

Diabetes in Pregnancy

Practice Questions

Adrenal Disorders in Pregnancy

Practice Questions

Pituitary Disorders in Pregnancy

Practice Questions

Hyperemesis Gravidarum

Practice Questions

Hormonal Regulation of Labor

Practice Questions

Pharmacokinetics of Hormones in Pregnancy

Practice Questions

Fetal Endocrine Development

Practice Questions

Placental Hormones

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free