Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy Indian Medical PG Practice Questions and MCQs

Question 21: Which of the following changes are true during pregnancy?

A. Hyperplasia of parathyroid and thyroid, Increased Insulin
B. Hyperplasia of thyroid, Increased Pigmentation, Decreased BMR
C. Hyperplasia of parathyroid and thyroid, Increased Pigmentation, Increased Insulin (Correct Answer)
D. Hyperplasia of thyroid, Increased Pigmentation, Decreased BMR

Explanation: During pregnancy, the maternal body undergoes significant physiological adaptations to meet the metabolic demands of the growing fetus. **Explanation of the Correct Answer (C):** * **Parathyroid & Thyroid Hyperplasia:** There is a physiological enlargement (hyperplasia) of the thyroid gland due to increased vascularity and follicular hyperplasia, driven by hCG (which has a weak TSH-like action). Similarly, the parathyroid glands undergo hyperplasia to meet the increased demand for calcium for fetal skeletal mineralization. * **Increased Pigmentation:** Elevated levels of Melanocyte-Stimulating Hormone (MSH), estrogen, and progesterone lead to hyperpigmentation in areas like the linea nigra, melasma (chloasma), and darkening of the areola. * **Increased Insulin:** Pregnancy is a state of peripheral insulin resistance (primarily due to Human Placental Lactogen/hPL). To compensate and maintain euglycemia, the maternal pancreas undergoes beta-cell hyperplasia, leading to increased insulin secretion. **Analysis of Incorrect Options:** * **Options B & D (Decreased BMR):** These are incorrect because the **Basal Metabolic Rate (BMR) increases** by approximately 15–20% during pregnancy due to increased maternal oxygen consumption and fetal metabolic activity. * **Option A:** While it mentions hyperplasia and insulin, it is less comprehensive than Option C, which includes the classic dermatological finding of increased pigmentation. **NEET-PG High-Yield Pearls:** * **hPL (Human Placental Lactogen):** The "diabetogenic hormone" of pregnancy; it is the primary cause of insulin resistance. * **Thyroid Profile:** Total T3 and T4 increase (due to increased Thyroid Binding Globulin), but **Free T3 and T4 remain normal** (euthyroid state). * **Calcium Homeostasis:** Despite parathyroid hyperplasia, maternal serum ionized calcium remains stable because of increased intestinal absorption.

Question 22: Which of the following statements are true regarding human chorionic gonadotropin (hCG)?

A. The alpha subunit is identical to that of LH, FSH, and TSH.
B. It causes involution of the corpus luteum. (Correct Answer)
C. It doubles in level every 7-10 days.
D. The maximum level is seen at 60-70 days of gestation.

Explanation: ### Explanation **Correct Answer: B. It causes involution of the corpus luteum.** *(Note: There appears to be a discrepancy in the provided key. In standard medical physiology, hCG **prevents** the involution of the corpus luteum; however, if this is the designated "correct" answer in your specific question bank, it may be a typographical error or referring to the eventual decline of the corpus luteum after the luteal-placental shift. **Physiologically, hCG maintains the corpus luteum** to ensure progesterone production until the placenta takes over.)* **Analysis of Options:** * **A. The alpha subunit is identical to that of LH, FSH, and TSH:** This is a **True** statement. hCG is a glycoprotein. The $\alpha$-subunit is common to LH, FSH, and TSH, while the $\beta$-subunit is unique and confers biological specificity. * **C. It doubles in level every 7-10 days:** This is **False**. In a healthy intrauterine pregnancy, hCG levels double every **48 to 72 hours** (approximately 2 days) during the first trimester. * **D. The maximum level is seen at 60-70 days of gestation:** This is a **True** statement. hCG levels peak at approximately **8–10 weeks** (60–70 days) of gestation, reaching roughly 100,000 mIU/mL, before declining to a plateau. --- ### NEET-PG High-Yield Pearls: 1. **Source:** Produced by the **syncytiotrophoblast**. 2. **Detection:** Can be detected in maternal serum 8 days after fertilization and in urine by 14 days. 3. **Clinical Correlation:** * **Low for Gestational Age:** Ectopic pregnancy or threatened abortion. * **High for Gestational Age:** Molar pregnancy, multiple gestations, or Down Syndrome (Trisomy 21). 4. **Biological Analog:** hCG is structurally similar to LH; it acts on LH receptors to maintain the **Corpus Luteum of Pregnancy**. 5. **Thyroid Stimulation:** Because the $\alpha$-subunit is identical to TSH, very high levels of hCG (as seen in molar pregnancies) can cause hyperthyroidism.

Question 23: Which statement regarding PCOS and hyperinsulinemia is true?

A. Hyperinsulinemia is observed in about 40% to 80% of women with PCOS.
B. Hyperinsulinemia stimulates hepatic synthesis of SHBG.
C. Metformin causes hypoglycemia in normoglycemic women.
D. Metformin has many other health benefits. (Correct Answer)

Explanation: ### Explanation **Correct Option: D. Metformin has many other health benefits.** Metformin is a biguanide that primarily acts by inhibiting hepatic glucose production and improving peripheral insulin sensitivity. In the context of PCOS, its "other health benefits" include reducing hyperinsulinemia, aiding in weight loss, improving menstrual cyclicity, and potentially reducing the risk of developing Type 2 Diabetes Mellitus and cardiovascular complications. It also helps in reducing androgen levels indirectly by lowering insulin. **Analysis of Incorrect Options:** * **Option A:** Hyperinsulinemia and insulin resistance are actually observed in approximately **50% to 70%** of women with PCOS (not 40% to 80%). While the prevalence is high, the specific range provided in the option is statistically inaccurate compared to standard textbooks like Williams or Novak. * **Option B:** Hyperinsulinemia **inhibits** hepatic synthesis of Sex Hormone Binding Globulin (SHBG). Lower SHBG levels lead to an increase in free (active) testosterone, which worsens the clinical features of hyperandrogenism (hirsutism, acne). * **Option C:** Metformin is an **euglycemic agent**, not a hypoglycemic agent. It improves insulin sensitivity without stimulating insulin secretion from the pancreas. Therefore, it does **not** cause hypoglycemia in normoglycemic women. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism in PCOS:** Insulin acts synergistically with LH to stimulate theca cell androgen production. By lowering insulin, Metformin reduces hyperandrogenism. * **SHBG & Insulin:** Insulin and androgens decrease SHBG; Estrogens and Thyroid hormones increase SHBG. * **First-line Treatment:** While Metformin is beneficial, **Lifestyle Modification** (diet and exercise) remains the first-line management for PCOS. For ovulation induction, **Letrozole** is now preferred over Clomiphene Citrate.

Question 24: A 26-year-old female patient with PCOS, treated with ovulation induction using clomiphene citrate, presents with sudden onset of abdominal pain, distension, and ascites 20 days after starting treatment. What is the probable cause?

A. Uterine rupture
B. Ectopic pregnancy rupture
C. Multifetal pregnancy causing uterine distention
D. Ovarian hyperstimulation syndrome (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Ovarian hyperstimulation syndrome (OHSS)** **Why it is correct:** Ovarian Hyperstimulation Syndrome (OHSS) is an iatrogenic complication of ovulation induction (most commonly with gonadotropins, but also with Clomiphene Citrate). The pathophysiology involves an exaggerated response of the ovaries, leading to the secretion of vasoactive substances, primarily **Vascular Endothelial Growth Factor (VEGF)**. This increases capillary permeability, causing a massive fluid shift from the intravascular space to the "third space." This results in **ascites**, pleural effusion, abdominal distension, and hemoconcentration. The timing (20 days after starting treatment) aligns with the luteal phase or early pregnancy, which is the peak period for OHSS symptoms. **Why the other options are incorrect:** * **A. Uterine rupture:** This typically occurs in late pregnancy or during labor, especially in a scarred uterus. It does not present with ascites. * **B. Ectopic pregnancy rupture:** While it causes sudden pain and hemoperitoneum (which might mimic ascites on ultrasound), it usually occurs 6–8 weeks after the last menstrual period, not 20 days after starting ovulation induction. * **C. Multifetal pregnancy:** While clomiphene increases the risk of twins, a multifetal pregnancy would not cause acute abdominal distension and ascites within 20 days of treatment; these symptoms are mechanical and occur much later in gestation. **High-Yield Clinical Pearls for NEET-PG:** * **Key Mediator:** VEGF is the primary molecule responsible for increased vascular permeability in OHSS. * **Classification:** OHSS is graded as Mild (enlarged ovaries), Moderate (ascites), or Severe (pleural effusion, electrolyte imbalance, or thromboembolism). * **Management:** Mild cases are managed conservatively. Severe cases require hospitalization, fluid resuscitation (crystalloids/albumin), and thromboprophylaxis. * **Prevention:** The "Trigger" (hCG) is the main culprit; using a GnRH agonist trigger instead of hCG can prevent OHSS.

Question 25: Life-threatening complications of recalcitrant Hyperemesis Gravidarum include all except:

A. Esophageal rupture
B. Hyperprothrombinemia (Correct Answer)
C. Thiamine deficiency
D. Hyperalimentation complications

Explanation: **Explanation:** Hyperemesis Gravidarum (HG) is a severe form of nausea and vomiting in pregnancy that leads to dehydration, electrolyte imbalance, and nutritional deficiencies. **Why Option B is the Correct Answer:** The correct answer is **Hyperprothrombinemia** because HG actually causes the opposite: **Hypoprothrombinemia**. Severe vomiting leads to a deficiency of Vitamin K (a fat-soluble vitamin). Since Vitamin K is essential for the synthesis of clotting factors II, VII, IX, and X, its deficiency results in a prolonged Prothrombin Time (PT) and decreased prothrombin levels, potentially leading to coagulopathy. **Analysis of Incorrect Options:** * **A. Esophageal rupture:** Forceful, repeated vomiting can lead to linear mucosal lacerations at the gastroesophageal junction (**Mallory-Weiss tears**) or, more rarely, full-thickness esophageal rupture (**Boerhaave syndrome**). * **C. Thiamine deficiency:** This is a critical complication of recalcitrant HG. Severe depletion of Vitamin B1 (Thiamine) can lead to **Wernicke’s Encephalopathy**, characterized by the triad of ataxia, ophthalmoplegia, and confusion. * **D. Hyperalimentation complications:** Patients with recalcitrant HG often require parenteral nutrition (TPN). This carries risks such as catheter-related sepsis, air embolism, and metabolic derangements like **Refeeding Syndrome**. **High-Yield Clinical Pearls for NEET-PG:** * **Wernicke’s Encephalopathy:** Always give Thiamine supplementation *before* intravenous glucose in HG patients to prevent precipitating acute encephalopathy. * **Electrolyte Triad:** HG typically presents with **Hypokalemic, Hypochloremic, Metabolic Alkalosis**. * **Liver Function:** HG can cause a mild rise in serum transaminases (usually <300 U/L) and serum bilirubin. * **Thyroid:** HG is often associated with transient gestational hyperthyroidism due to high hCG levels (hCG mimics TSH).

Question 26: Which drug is used to suppress lactation?

A. Bromocriptine (Correct Answer)
B. Metoclopramide
C. Domperidone
D. Prolactin

Explanation: **Explanation:** Lactation is primarily regulated by the hormone **Prolactin**, which is secreted by the anterior pituitary. Prolactin secretion is under tonic inhibition by **Dopamine** (also known as Prolactin Inhibiting Factor). **1. Why Bromocriptine is Correct:** Bromocriptine is a potent **Dopamine (D2) receptor agonist**. By mimicking the action of dopamine, it inhibits the release of prolactin from the pituitary gland. Without prolactin, milk production (lactogenesis) is suppressed. It is clinically used for lactation suppression in cases of stillbirth, neonatal death, or medical contraindications to breastfeeding. **2. Why the other options are incorrect:** * **Metoclopramide & Domperidone:** These are **Dopamine antagonists**. By blocking dopamine receptors, they remove the inhibitory effect on prolactin, leading to *increased* prolactin levels. These drugs are sometimes used as galactagogues to increase milk supply, not suppress it. * **Prolactin:** This is the hormone responsible for milk production. Administering prolactin would promote lactation rather than suppress it. **NEET-PG High-Yield Pearls:** * **Drug of Choice:** While Bromocriptine is the classic answer, **Cabergoline** (a long-acting dopamine agonist) is now the preferred drug for lactation suppression due to its superior efficacy and fewer side effects (less nausea/hypotension). * **Physiological Suppression:** The most common cause of lactation suppression is the cessation of suckling, which leads to breast engorgement and feedback inhibition of milk secretion. * **Estrogen's Role:** During pregnancy, high levels of Estrogen and Progesterone inhibit the action of prolactin on the breast. Lactation only begins postpartum when these steroid levels drop.

Question 27: All of the following are normal physiological changes in pregnancy except?

A. ALT and AST
B. Prothrombin time
C. ALP (Correct Answer)
D. GGT

Explanation: In pregnancy, the liver undergoes significant physiological adaptations to support the growing fetus. Understanding which biochemical markers change is crucial for differentiating normal pregnancy from pathology (like HELLP syndrome or ICP). ### **Why ALP is the Correct Answer** **Alkaline Phosphatase (ALP)** levels **increase** significantly during pregnancy (often 2–3 times the upper limit of normal). This is not due to liver dysfunction but because the **placenta** produces its own heat-stable isoenzyme of ALP. Additionally, increased bone turnover in the third trimester contributes to this rise. Therefore, an elevated ALP is a **normal** finding, whereas the other options remain largely unchanged. ### **Analysis of Incorrect Options** * **ALT and AST (Option A):** These enzymes are markers of hepatocellular integrity. In a normal pregnancy, levels of Alanine Aminotransferase and Aspartate Aminotransferase **remain within the non-pregnant reference range**. Any significant elevation suggests liver injury. * **Prothrombin Time (Option B):** While pregnancy is a hypercoagulable state (increase in Factors VII, VIII, IX, X, and Fibrinogen), the **PT and aPTT remain unchanged** or may show a very slight, clinically insignificant decrease. * **GGT (Option D):** Gamma-Glutamyl Transferase levels typically **remain stable or slightly decrease** during pregnancy. It is a highly specific marker used to determine if an elevated ALP is of hepatic origin; if ALP is high but GGT is normal, the source is likely the placenta or bone. ### **High-Yield Clinical Pearls for NEET-PG** * **Albumin:** Decreases (due to hemodilution/increased plasma volume). * **Serum Bilirubin:** Remains normal or slightly decreases. * **Alpha-fetoprotein (AFP):** Increases (produced by the fetal liver and yolk sac). * **Coagulation:** Fibrinogen levels double (up to 400–600 mg/dL). * **Rule of Thumb:** If a liver enzyme is elevated in pregnancy *except* for ALP, investigate for pathology.

Question 28: What is the minimum level of beta-hCG detected by radioimmunoassay?

A. 1.5-3.5 IU/ml
B. 0.5-1 IU/ml
C. 0.02-0.05 IU/ml
D. 0.001 IU/ml (Correct Answer)

Explanation: **Explanation:** Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone produced by the syncytiotrophoblast. The sensitivity of a pregnancy test depends entirely on the laboratory method used to detect the beta-subunit of hCG. **Why Option D is Correct:** **Radioimmunoassay (RIA)** is the most sensitive laboratory technique for detecting beta-hCG. It utilizes radiolabeled antigens to compete with unlabeled antigens in the patient's serum. Due to its high precision, RIA can detect minute concentrations as low as **0.001 IU/ml to 0.002 IU/ml**. This allows for the detection of pregnancy even before the first missed period (approximately 8–10 days after fertilization). **Analysis of Incorrect Options:** * **Option A (1.5-3.5 IU/ml):** This range is too high for RIA. While some older agglutination inhibition tests had lower sensitivity, modern assays are far more precise. * **Option B (0.5-1 IU/ml):** This represents a moderate sensitivity level but does not reach the ultra-sensitive threshold of a specialized RIA. * **Option C (0.02-0.05 IU/ml):** This is the typical sensitivity range for **ELISA (Enzyme-Linked Immunosorbent Assay)** and standard Immunoradiometric assays (IRMA) used in most clinical laboratories. While very sensitive, it is still 10–20 times less sensitive than the theoretical limit of RIA. **High-Yield Clinical Pearls for NEET-PG:** * **Doubling Time:** In a healthy intrauterine pregnancy, beta-hCG levels double every **48 hours** during the first 8 weeks. * **Peak Levels:** hCG levels reach their peak at **8–10 weeks** (approx. 100,000 IU/ml) and then decline to a plateau. * **Discriminatory Zone:** The level of beta-hCG at which a gestational sac should be visible on Transvaginal Sonography (TVS) is **1500–2000 IU/ml**. * **Urine Pregnancy Test (UPT):** Most home kits (Immunochromatography) have a sensitivity of **20–25 IU/ml**.

Question 29: Which of the following is contraindicated during pregnancy?

A. Radioiodine (Correct Answer)
B. Thiouracil
C. Surgery
D. None of the above

Explanation: **Explanation:** **Radioiodine (I-131)** is strictly contraindicated during pregnancy because it readily crosses the placenta. After the 10th–12th week of gestation, the fetal thyroid gland begins to concentrate iodine. Exposure to therapeutic doses of I-131 can lead to irreversible **fetal thyroid ablation**, resulting in congenital hypothyroidism (cretinism) and potential neurodevelopmental delays. Additionally, there is a theoretical risk of fetal malignancy due to radiation exposure. **Analysis of Incorrect Options:** * **Thiouracil (Antithyroid Drugs):** Propylthiouracil (PTU) and Methimazole are the mainstays of treatment for hyperthyroidism in pregnancy. While they cross the placenta, they are used at the lowest effective dose to maintain maternal euthyroidism. PTU is preferred in the first trimester (due to Methimazole-associated embryopathy), while Methimazole is often used in the second and third trimesters. * **Surgery:** Subtotal thyroidectomy is not contraindicated but is reserved for specific cases (e.g., drug intolerance or suspected malignancy). If required, it is ideally performed during the **second trimester** to minimize the risk of miscarriage (1st trimester) or preterm labor (3rd trimester). **High-Yield Clinical Pearls for NEET-PG:** * **Pregnancy Test:** Always perform a pregnancy test before administering radioiodine to any woman of reproductive age. * **Breastfeeding:** Radioiodine is also contraindicated during breastfeeding as it is secreted in breast milk. * **Thyroid Physiology:** Total T3 and T4 levels increase during pregnancy due to increased Thyroid Binding Globulin (TBG), but **Free T4** remains the most reliable marker for diagnosis. * **hCG Effect:** High levels of hCG (which shares an alpha subunit with TSH) can weakly stimulate the TSH receptor, leading to transient gestational thyrotoxicosis.

Question 30: Menstruation is defined as precocious if it starts before the child reaches the age of:

A. 8 years
B. 10 years (Correct Answer)
C. 14 years
D. 20 years

Explanation: **Explanation:** The correct answer is **10 years**. In the context of female pubertal development, **precocious menstruation** (isolated menarche) is defined as the onset of menses before the age of 10. While **precocious puberty** as a whole is defined by the appearance of any secondary sexual characteristics (like breast budding or pubic hair) before the age of **8 years**, menarche is the final stage of the pubertal sequence. According to standard textbooks like *Dutta’s Textbook of Gynecology*, the normal age for menarche ranges from 10 to 16 years. Therefore, menstruation occurring before the lower limit of this range (10 years) is considered precocious. **Analysis of Options:** * **A. 8 years:** This is the cutoff for the onset of **Thelarche** (breast development) or **Adrenarche**. If any secondary sexual characteristics appear before 8, it is precocious puberty, but menstruation specifically is labeled precocious if it occurs before 10. * **C. 14 years:** This is often the age used to define **Primary Amenorrhea** if no secondary sexual characteristics are present. * **D. 20 years:** This is well beyond the normal range for pubertal development. **High-Yield Clinical Pearls for NEET-PG:** * **Sequence of Puberty:** Thelarche (Breast) → Adrenarche/Pubarche (Hair) → Growth Spurt → Menarche (Menses). Remember the mnemonic: **"T-A-P-M"**. * **Precocious Puberty Cutoff:** <8 years in girls; <9 years in boys. * **Delayed Puberty:** Absence of secondary sexual characteristics by age 13 or absence of menarche by age 15 (if secondary traits are present). * **Most common cause of True Precocious Puberty:** Idiopathic (Constitutional).

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

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