Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy Indian Medical PG Practice Questions and MCQs

Question 261: Which of the following statements about cholestasis of pregnancy is false?

A. Bilirubin level >2mg%
B. Most common cause of jaundice in pregnancy (Correct Answer)
C. Oestrogen is involved
D. Manifestations usually appear in last trimester

Explanation: ***Most common cause of jaundice in pregnancy*** - This statement is **FALSE** - while **intrahepatic cholestasis of pregnancy (ICP)** is the most common **pregnancy-specific** cause of jaundice, it is NOT the most common cause of jaundice overall in pregnancy. - **Viral hepatitis** (especially hepatitis A, B, and E) remains the **most common cause of jaundice in pregnancy** worldwide, accounting for approximately 40-50% of cases. - ICP accounts for about 20-25% of jaundice cases in pregnancy, making it the leading obstetric-specific cause but not the overall leading cause. *Bilirubin level >2mg%* - In ICP, **bilirubin levels** are typically **normal or only mildly elevated** (usually <4 mg/dL, often <2 mg/dL). - However, bilirubin **can exceed 2 mg/dL** in some cases of ICP, particularly in more severe presentations. - The primary diagnostic marker is elevated **serum bile acids** (>10 μmol/L), not bilirubin. *Oestrogen is involved* - **TRUE** - Elevated **estrogen and progesterone levels** during pregnancy play a key role in ICP pathophysiology. - These hormones affect **hepatic bile salt transporters** (particularly BSEP and MDR3), leading to impaired bile secretion in genetically susceptible individuals. *Manifestations usually appear in last trimester* - **TRUE** - ICP typically presents in the **third trimester** (usually after 28 weeks), with **pruritus** as the predominant symptom. - Symptoms resolve within days to weeks after delivery, correlating with declining hormone levels.

Question 262: The "cutoff" value of plasma glucose in a 50-g glucose challenge test is

A. 120 mg/dL
B. 140 mg/dL (Correct Answer)
C. 160 mg/dL
D. 180 mg/dL

Explanation: ***140 mg/dL*** - A plasma glucose level of **140 mg/dL** (7.8 mmol/L) or higher one hour after a **50-g glucose challenge** is considered abnormal and warrants further investigation with a 3-hour oral glucose tolerance test (OGTT). - This cutoff helps identify individuals at risk for **gestational diabetes mellitus (GDM)**. *120 mg/dL* - This value is below the established cutoff for an abnormal 50-g glucose challenge test. - A plasma glucose level of 120 mg/dL one hour after glucose intake is generally considered within the **normal range** for this screening test. *160 mg/dL* - While 160 mg/dL is an elevated value, the standard cutoff used to indicate a positive screen is 140 mg/dL. - Using a higher cutoff like 160 mg/dL would **decrease the sensitivity** of the screening test, potentially missing cases of gestational diabetes. *180 mg/dL* - A plasma glucose level of 180 mg/dL is significantly elevated and would certainly lead to further testing. - However, the American College of Obstetricians and Gynecologists (ACOG) and other major organizations recommend the **140 mg/dL cutoff** for initial screening to maximize sensitivity.

Question 263: Estrogen is secreted during pregnancy, mostly by which organ?

A. Placenta (Correct Answer)
B. Fetal ovary
C. Pituitary
D. Hypothalamus

Explanation: ***Placenta*** - During pregnancy, the **placenta** takes over the primary role of **estrogen production** from the ovaries, especially after the first trimester. - It synthesizes significant amounts of **estriol**, the main estrogen produced during pregnancy, using precursors from the fetal adrenal glands. *Fetal ovary* - The **fetal ovary** is not the primary source of estrogen synthesis during pregnancy. - While it has some hormonal activity, it does not produce the large quantities of estrogen needed to support the pregnancy. *Pituitary* - The **pituitary gland** produces hormones like **FSH and LH**, which regulate ovarian function, but it does not directly secrete estrogen itself. - Its role is supervisory, not secretory of sex steroids. *Hypothalamus* - The **hypothalamus** secretes **gonadotropin-releasing hormone (GnRH)**, which stimulates the pituitary, but it does not produce estrogen. - It is part of the central control system for reproductive hormones, not a direct estrogen secretor.

Question 264: Which of the following statements about placental hormones is true?

A. hCS plays a role in maternal glucose metabolism. (Correct Answer)
B. hCG levels remain consistently high throughout pregnancy.
C. The luteal-placental shift occurs around 10-12 weeks of gestation.
D. Progesterone production requires fetal adrenal precursors.

Explanation: **Correct: *hCS plays a role in maternal glucose metabolism.*** - **Human chorionic somatomammotropin (hCS)**, also known as placental lactogen, has **anti-insulin effects** that reduce maternal glucose utilization. - This action diverts glucose to the fetus, helping to meet the growing **fetal energy demands**. *Incorrect: hCG levels remain consistently high throughout pregnancy.* - **hCG (human chorionic gonadotropin)** levels peak in the first trimester (around 8-10 weeks) and then **decline and plateau** at much lower levels for the remainder of the pregnancy. - Its primary role is to maintain the **corpus luteum** during early pregnancy. *Incorrect: The luteal-placental shift occurs around 10-12 weeks of gestation.* - The **luteal-placental shift**, where the placenta takes over progesterone production from the corpus luteum, occurs around **7-9 weeks of gestation**. - By 10-12 weeks, the placenta is already the primary producer of progesterone. *Incorrect: Progesterone production requires fetal adrenal precursors.* - **Progesterone** is synthesized by the placenta from **maternal cholesterol** without requiring fetal steroid precursors. - **Estrogen**, particularly **estriol**, on the other hand, relies on **fetal adrenal androgens** as precursors.

Question 265: At any given point during pregnancy, AFP levels are highest in:

A. Fetal serum (Correct Answer)
B. Placenta
C. Amniotic fluid
D. Maternal serum

Explanation: ***Fetal serum*** - **Alpha-fetoprotein (AFP)** is primarily produced by the **fetal yolk sac** and then the **fetal liver**, leading to the highest concentrations directly in the fetal circulation. - AFP serves as the fetal equivalent of **albumin** and is crucial for regulating osmotic pressure and transporting various substances in the fetus. *Placenta* - The placenta acts as a **barrier** and site of exchange between the mother and fetus, but it does not produce significant amounts of AFP itself. - While AFP passes through the placenta, its concentration within the placental tissue itself is not the highest. *Amniotic fluid* - AFP enters the **amniotic fluid** through fetal urination and transudation from fetal serum across fetal membranes and skin. - Although detectable in amniotic fluid, its levels are significantly lower than in the fetal bloodstream from which it originates. *Maternal serum* - **Maternal serum AFP (MSAFP)** levels are much lower than fetal serum or even amniotic fluid levels because only a small fraction of fetal AFP crosses the placenta into the maternal circulation. - MSAFP is used as a screening tool, but its concentration reflects the *diluted* presence of fetal AFP.

Question 266: Hypothyroidism in pregnancy is most likely associated with which of the following?

A. Recurrent abortions
B. Preeclampsia (Correct Answer)
C. Preterm labour
D. Polyhydramnios

Explanation: ***Preeclampsia*** - **Hypothyroidism** in pregnancy is strongly linked to an increased risk of **preeclampsia**, a serious condition characterized by **hypertension and proteinuria** after 20 weeks of gestation. - The exact mechanism is not fully understood, but thyroid hormones play a crucial role in maintaining **vascular tone and endothelial function**, which are disrupted in preeclampsia. - Studies show that both **overt and subclinical hypothyroidism** increase the risk of preeclampsia, making this the **most likely association** among the given options. *Recurrent abortions* - While uncontrolled **hypothyroidism** can increase the risk of **first-trimester miscarriage**, it is not typically cited as the most likely association for **recurrent abortions** compared to preeclampsia. - Other causes like **chromosomal abnormalities, uterine anomalies, or antiphospholipid syndrome** are more common for recurrent pregnancy loss. - Early detection and treatment with **levothyroxine** can reduce miscarriage risk. *Polyhydramnios* - **Polyhydramnios** (excess amniotic fluid) is more often associated with conditions like **gestational diabetes**, fetal anomalies (e.g., GI obstruction, neural tube defects), or multiple gestation. - **Hypothyroidism** is not a primary risk factor for **polyhydramnios**; fetal thyroid dysfunction (e.g., fetal hyperthyroidism due to maternal Graves' disease) is more relevant to amniotic fluid disorders. - Maternal hypothyroidism does not typically affect amniotic fluid volume. *Preterm labour* - Poorly controlled **hypothyroidism** can increase the risk of **preterm birth**, but **preeclampsia** is generally considered a more distinct and stronger association. - Other common causes of **preterm labor** include infections, uterine abnormalities, cervical insufficiency, and multiple gestations. - Adequate thyroid hormone replacement reduces obstetric complications including preterm delivery.

Question 267: Which of the following endocrinological conditions may be associated with hydatidiform mole: 46,XX?

A. Hypothyroidism
B. Diabetes
C. Hyperprolactinemia
D. Hyperthyroidism (Correct Answer)

Explanation: ***Hyperthyroidism*** - A **complete hydatidiform mole** produces very high levels of **human chorionic gonadotropin (hCG)**, which has a structural similarity to **thyroid-stimulating hormone (TSH)**. - This **hCG** can bind to **TSH receptors** on the thyroid gland, stimulating **thyroid hormone production** and leading to **hyperthyroidism**. *Hypothyroidism* - **Hypothyroidism** is characterized by **low thyroid hormone levels** and is not directly induced by the hormonal changes associated with a hydatidiform mole. - While pregnancy can sometimes unmask or worsen hypothyroidism, it is not a direct endocrinological consequence of a molar pregnancy. *Diabetes* - **Diabetes mellitus** is a metabolic disorder characterized by **high blood glucose**, commonly associated with insulin resistance or deficiency. - There is no direct endocrinological link between **hydatidiform mole** and the development of diabetes. *Hyperprolactinemia* - **Hyperprolactinemia** is characterized by **elevated prolactin levels**, often leading to menstrual irregularities and galactorrhea. - While pregnancy itself causes an increase in prolactin, a hydatidiform mole does not specifically induce pathological **hyperprolactinemia**.

Question 268: In normal pregnancy, β-HCG doubles in

A. 24 hours
B. 48 hours (Correct Answer)
C. 72 hours
D. 90 hours

Explanation: **48 hours** - In a **normal, singleton intrauterine pregnancy**, the serum β-HCG levels approximately **double every 48 hours** (or every 2 days) during early gestation. - This doubling time is a key indicator used to assess the viability and progression of a pregnancy in its initial stages. *24 hours* - A doubling time of 24 hours (or less) is **faster than typically observed** in normal pregnancies. - Such a rapid rise might sometimes be seen but is not the characteristic average doubling time for a healthy early pregnancy. *72 hours* - While a doubling time of up to 72 hours can still be considered within normal limits for some pregnancies, the **average and most common normal doubling time is 48 hours**. - A doubling time consistently longer than 48-72 hours can raise concern for an **ectopic pregnancy** or **miscarriage**. *90 hours* - A doubling time of 90 hours is **significantly prolonged** and is generally considered abnormal. - This slower rise in β-HCG is often indicative of a **non-viable pregnancy**, such as an evolving miscarriage or an ectopic pregnancy.

Question 269: Heat-stable alkaline phosphatase in pregnancy is primarily derived from which source?

A. The placenta (Correct Answer)
B. Maternal liver
C. Fetal liver
D. Maternal bone

Explanation: ***The placenta*** - The **placenta** is the primary source of heat-stable alkaline phosphatase (HSAP) during pregnancy. This specific isoform is distinct from other alkaline phosphatase isoforms. - Increased levels of HSAP are observed in maternal serum throughout pregnancy, reflecting **placental metabolic activity** and growth. - HSAP levels typically **rise progressively** from the first trimester and peak near term, serving as a marker of **placental function**. *Maternal liver* - The maternal liver produces **liver-specific alkaline phosphatase**, which is **not heat-stable**. - While liver ALP levels may fluctuate slightly in pregnancy, they are not the primary source of the heat-stable form. - Liver ALP is inactivated by heating at 56°C, unlike the placental isoform. *Fetal liver* - The fetal liver produces **alkaline phosphatase**, but this is not released into the maternal circulation in significant amounts as **heat-stable ALP**. - Fetal contribution to maternal serum **heat-stable ALP** is negligible compared to the placenta. - The placental barrier prevents significant transfer of fetal enzymes to maternal blood. *Maternal bone* - Maternal bone produces **bone-specific alkaline phosphatase**, which is also **not heat-stable**. - Bone ALP may increase during pregnancy due to skeletal remodeling, but it represents a different isoform. - Bone ALP can be distinguished from placental ALP by heat stability testing and electrophoresis.

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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