Endocrinology of Pregnancy Practice Questions

Q: During pregnancy, the maternal blood volume increases by nearly:

50%. **Explanation:** The correct answer is **50%**. Maternal blood volume begins to increase as early as the 6th week of gestation, reaching its peak expansion of approximately **40–50%** above non-pregnant levels by 32–34 weeks. **Why it is correct:** This physiological hypervolemia is driven by an increase in both plasma volume (approx. 45–50%) and red cell mass (approx. 20–30%). The primary purpose is to meet the metabolic demands of the enlarging uterus, protect the mother against the effects of decreased venous return in the supine position, and provide a "safety cushion" against blood loss during parturition. **Why other options are incorrect:** * **A & B (5-20%):** These values are far too low. Such minimal increases would be insufficient to support the uteroplacental circulation and would leave the mother vulnerable to hypovolemic shock during delivery. * **D (70%):** While blood volume increases significantly, a 70% increase is pathological and would place an extreme, unsustainable load on the maternal heart, potentially leading to high-output cardiac failure. **High-Yield Clinical Pearls for NEET-PG:** * **Physiological Anemia:** Because the plasma volume increases (50%) more than the red cell mass (20-30%), a state of **hemodilution** occurs. This results in a physiological drop in hemoglobin concentration (nadir usually at 30 weeks). * **Cardiac Output:** Increases by about 40%, peaking at 20–24 weeks. * **Stroke Volume:** Increases early in pregnancy, while **Heart Rate** increases later (by 10–15 bpm). * **Blood Pressure:** Diastolic BP decreases more than systolic BP, reaching its lowest point in the second trimester due to decreased systemic vascular resistance (SVR).

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

Polycystic ovary syndrome. **Explanation:** The hallmark of **Polycystic Ovary Syndrome (PCOS)** is a neuroendocrine derangement characterized by an increased frequency of GnRH pulses. This high-frequency pulsing preferentially stimulates the anterior pituitary to produce **LH** over FSH. Consequently, the **LH:FSH ratio is typically >2:1 or 3:1**. The elevated LH leads to hyperplasia of the ovarian theca cells and excessive androgen production, while the relatively low FSH results in poor follicular recruitment and the "necklace appearance" of subcapsular cysts. **Analysis of Incorrect Options:** * **Premature Menopause & Turner’s Syndrome:** Both are forms of hypergonadotropic hypogonadism (primary ovarian failure). In these conditions, the lack of negative feedback from estrogen leads to an elevation of both LH and FSH. However, **FSH rises more significantly** than LH because FSH has a longer half-life and slower clearance, resulting in a decreased LH:FSH ratio. * **Sheehan Syndrome:** This is a form of hypogonadotropic hypogonadism caused by postpartum pituitary necrosis. Here, the levels of **both LH and FSH are low** due to pituitary gland destruction. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for PCOS Diagnosis:** Rotterdam Criteria (requires 2 out of 3: Oligo/anovulation, Hyperandrogenism, and Polycystic ovaries on USG). * **Biochemical Marker:** Anti-Müllerian Hormone (AMH) levels are typically elevated in PCOS. * **Insulin Resistance:** This is a key driver in PCOS, often manifesting clinically as *Acanthosis nigricans*. * **FSH > 40 IU/L** is the diagnostic threshold for Premature Ovarian Failure (Premature Menopause).

Q: Destruction of ovaries prior to the 7th week following fertilization results in what?

None of the above. The correct answer is **D. None of the above.** ### **Explanation** The key to this question lies in understanding the **Luteo-Placental Shift** and the default pathway of female sexual differentiation. 1. **The Luteo-Placental Shift:** During early pregnancy, the corpus luteum of the ovary is the primary source of progesterone, which is essential for maintaining the pregnancy. However, between the **7th and 9th weeks** of gestation, the placenta takes over progesterone production. If the ovaries (and thus the corpus luteum) are removed **before the 7th week**, the pregnancy cannot be maintained, resulting in a **spontaneous abortion (miscarriage)** rather than developmental anomalies. 2. **Default Female Development:** In embryology, female phenotypic development is the "default" pathway. It occurs in the **absence** of the SRY gene and Testis Determining Factor (TDF). Unlike males, who require testosterone and Anti-Müllerian Hormone (AMH) for differentiation, female internal and external genitalia develop regardless of whether fetal ovaries are present or functional. ### **Why Incorrect Options are Wrong** * **A & C (Pseudohermaphroditism/Masculinisation):** These require the presence of androgens (e.g., Congenital Adrenal Hyperplasia). Removing ovaries removes a source of estrogen, but it does not introduce male hormones; therefore, masculinization does not occur. * **B (Uterine Agenesis):** The uterus develops from the Müllerian ducts. This process is independent of ovarian hormones and depends solely on the absence of AMH (which is produced by fetal testes). ### **High-Yield Clinical Pearls for NEET-PG** * **Luteo-placental shift:** Occurs between 7–9 weeks. * **Oophorectomy in pregnancy:** If required before 9 weeks, exogenous progesterone (e.g., 17-OHP) must be administered to prevent miscarriage. * **Müllerian Development:** Occurs automatically unless suppressed by AMH (Sertoli cells) and Testosterone (Leydig cells).

Q: What is the uterine blood flow at term?

500-750 ml/min. **Explanation:** The correct answer is **D (500-750 ml/min)**. In a non-pregnant state, uterine blood flow is approximately **50 ml/min**. During pregnancy, the uterus undergoes massive physiological adaptation to meet the metabolic demands of the growing fetus and placenta. By term, the uterine blood flow increases significantly, reaching **500-750 ml/min**, which represents about **10-15% of the total cardiac output**. This increase is facilitated by: 1. **Vasodilation:** Reduced vascular resistance due to the action of estrogen, progesterone, and nitric oxide. 2. **Remodeling:** Trophoblastic invasion of the spiral arteries, converting them into high-flow, low-resistance vessels. **Analysis of Incorrect Options:** * **Option A (800-1200 ml/min):** This value is too high and exceeds the typical physiological range for uterine perfusion, even at term. * **Option B (50-70 ml/min):** This represents the **pre-pregnancy** or non-gravid uterine blood flow. * **Option C (175-200 ml/min):** This represents uterine blood flow during the **second trimester** (around 20-24 weeks), before it reaches its peak at term. **NEET-PG High-Yield Pearls:** * **Distribution:** At term, approximately **80-90%** of the uterine blood flow is directed to the **placenta** (intervillous space), while the remainder supplies the myometrium. * **Positioning:** Uterine blood flow can be decreased by the **supine position** due to aortocaval compression (Supine Hypotension Syndrome). * **Autoregulation:** Unlike the brain or kidneys, the uteroplacental circulation lacks significant autoregulation; therefore, flow is directly dependent on maternal systemic blood pressure.

Q: A 26-year-old patient presents with secondary amenorrhea for 4 months. Serum prolactin and beta-hCG assays are ordered. The pregnancy test is positive, and the prolactin level is 100 ng/mL (normal <25 ng/mL). What is the most appropriate next step in management?

Routine obstetric care. **Explanation:** The correct answer is **Routine obstetric care**. **1. Why it is correct:** In a pregnant patient, a serum prolactin level of 100 ng/mL is a **physiological finding**. During pregnancy, prolactin levels rise progressively (often increasing 10-fold) due to estrogen-induced hypertrophy and hyperplasia of the lactotroph cells in the anterior pituitary. By the third trimester, levels can reach 200–400 ng/mL. Since the patient has a positive beta-hCG, the elevated prolactin is expected and does not require further investigation or intervention in the absence of visual field defects or severe headaches. **2. Why the other options are incorrect:** * **Option B:** CT or MRI of the sella turcica is unnecessary. Imaging is only indicated during pregnancy if the patient develops symptoms of tumor expansion (e.g., bitemporal hemianopia or intractable headaches). * **Option C:** Serial monitoring of prolactin during pregnancy is not recommended. Because levels fluctuate significantly and rise naturally, the values do not correlate with tumor growth and are clinically unreliable for monitoring. * **Option D:** Bromocriptine (a dopamine agonist) is used to treat symptomatic prolactinomas to induce ovulation. Once pregnancy is confirmed, it is typically discontinued unless the patient has a macroadenoma at high risk of expansion. It is never indicated for physiological hyperprolactinemia of pregnancy. **Clinical Pearls for NEET-PG:** * **Estrogen's Role:** Estrogen stimulates prolactin secretion but simultaneously inhibits its action on the breast, preventing lactation until the postpartum drop in estrogen/progesterone. * **Pituitary Size:** The pituitary gland increases in size by approximately 136% during pregnancy. * **Rule of Thumb:** Always rule out pregnancy first in any woman of reproductive age presenting with amenorrhea or hyperprolactinemia.

Q: What is the typical subcostal angle during pregnancy?

105 degrees. **Explanation:** The correct answer is **105 degrees (Option C)**. **Underlying Medical Concept:** During pregnancy, the enlarging uterus causes a progressive upward displacement of the diaphragm by approximately 4 cm. To compensate for this and maintain lung volume, the rib cage undergoes significant structural remodeling. The rib cage flares outwards, increasing the transverse diameter of the chest by about 2 cm and the circumference by 5–7 cm. Consequently, the **subcostal angle increases significantly from a baseline of approximately 68 degrees in non-pregnant women to about 103–105 degrees** in late pregnancy. This change occurs early in pregnancy, often before the mechanical pressure of the uterus is significant, suggesting hormonal influence (likely Relaxin) on the ligamentous attachments of the ribs. **Analysis of Options:** * **Option A (85°) & B (95°):** These values represent intermediate stages of widening but are lower than the peak subcostal angle reached at term (approx. 105°). * **Option D (75°):** This is closer to the normal non-pregnant subcostal angle (approx. 68–70°). **High-Yield Clinical Pearls for NEET-PG:** * **Diaphragmatic Excursion:** Despite the 4 cm elevation, diaphragmatic excursion is actually *increased* or remains normal during pregnancy; it is not restricted. * **Tidal Volume:** Increases by 40% (the most significant change in respiratory parameters). * **Functional Residual Capacity (FRC):** Decreases by 20% due to the elevation of the diaphragm. * **Respiratory Rate:** Remains largely unchanged; the increase in Minute Ventilation is driven by increased Tidal Volume. * **Acid-Base Status:** Pregnancy is a state of chronic **compensated respiratory alkalosis** (due to progesterone-driven hyperventilation).

Question 1

Concerning the gastrointestinal (GI) tract during pregnancy, which of the following is true?

Accepted Answer

Pyrosis is caused by reflux of acidic secretions into the lower esophagus

Answer

Gastric emptying time is increased in each trimester

Answer

Epulis is a systemic, highly vascular swelling of mucosal membranes

Answer

Gastric emptying time is shortened during labor

Question 2

Which of the following are features of diabetes mellitus in pregnancy?

Accepted Answer

Hydramnios, Neonatal hyperglycemia, Increased congenital defects

Answer

Postdatism, Neonatal hyperglycemia, Increased congenital defects

Answer

Postdatism, Neonatal hyperglycemia, Postpartum hemorrhage

Answer

Hydramnios, Neonatal hyperglycemia, Postpartum hemorrhage

Question 3

During pregnancy, the maternal blood volume increases by nearly:

Accepted Answer

50%

Answer

5-10%

Answer

15-20%

Answer

70%

Question 4

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

Accepted Answer

Polycystic ovary syndrome

Answer

Premature menopause

Answer

Sheehan syndrome

Answer

Turner's syndrome

Question 5

Destruction of ovaries prior to the 7th week following fertilization results in what?

Accepted Answer

None of the above

Answer

Pseudohermaphroditism

Answer

Uterine agenesis

Answer

Masculinisation

Question 6

Pregnant women with obesity are at higher risk of the following, except?

Accepted Answer

Infections

Answer

Fetal macrosomia

Answer

Fetal distress

Answer

Gestational hypertension

Question 7

What is the uterine blood flow at term?

Accepted Answer

500-750 ml/min

Answer

800-1200 ml/min

Answer

50-70 ml/min

Answer

175-200 ml/min

Question 8

A 26-year-old patient presents with secondary amenorrhea for 4 months. Serum prolactin and beta-hCG assays are ordered. The pregnancy test is positive, and the prolactin level is 100 ng/mL (normal <25 ng/mL). What is the most appropriate next step in management?

Accepted Answer

Routine obstetric care

Answer

Computed tomography (CT) scan of the sella turcica to rule out pituitary adenoma

Answer

Repeat measurements of serum prolactin to ensure that values do not increase over 300 ng/mL

Answer

Bromocriptine to suppress prolactin

Question 9

What is the typical subcostal angle during pregnancy?

Accepted Answer

105 degrees

Answer

85 degrees

Answer

95 degrees

Answer

75 degrees

Question 10

Which statement is false regarding human chorionic gonadotropin (hCG)?

Accepted Answer

It is synthesized by the syncytiotrophoblast.

Answer

It is a glycopeptide.

Answer

Its level doubles approximately every 2 days in early pregnancy.

Answer

High levels are observed in multiple pregnancies.

Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy — MCQs

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