Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy Indian Medical PG Practice Questions and MCQs

Question 241: Blood volume increases during pregnancy above nonpregnant level at 30-34 weeks by:

A. Blood volume does not increase at all
B. by 25-30 per cent
C. by 40-50 per cent (Correct Answer)
D. by 10-20 per cent

Explanation: ***by 40-50 per cent*** - During pregnancy, **blood volume significantly increases**, primarily due to hormonal changes, to support the growing fetus and uteroplacental unit, with the peak increase typically occurring around the third trimester. - This expansion involves both **plasma volume (greater increase)** and **red blood cell mass**, leading to a state of physiologic hemodilution. *Blood volume does not increase at all* - This statement is incorrect as a substantial **increase in blood volume is a hallmark of normal pregnancy physiology** to meet increased metabolic demands. - Failure of blood volume to increase would imply a pathologic state, potentially compromising both maternal and fetal well-being. *by 25-30 per cent* - While a significant increase, **25-30% is generally an underestimation** of the full extent of blood volume expansion that occurs in a healthy pregnancy. - The total increase often reaches higher values, particularly when considering the combined rise in plasma and red blood cells. *by 10-20 per cent* - An increase of **10-20% is considerably less** than what is typically observed during a normal pregnancy. - This level of increase would likely be insufficient to adequately support the physiological demands of the mother and fetus.

Question 242: The peak level of human chorionic gonadotropin in normal pregnancy occurs between:

A. 30 to 40 days after pregnancy
B. 100 to 120 days after pregnancy
C. 10 to 12 days after pregnancy
D. 60 to 70 days after pregnancy (Correct Answer)

Explanation: ***60 to 70 days after pregnancy*** - Peak **hCG levels** in normal singleton pregnancies are typically observed between **9-10 weeks of gestation**, which corresponds to approximately **63-70 days after the last menstrual period (LMP)** or fertilization. - This period marks the highest physiological levels of hCG, crucial for maintaining the **corpus luteum** and early pregnancy. *30 to 40 days after pregnancy* - At this stage (approximately 4-5 weeks gestation), hCG levels are **rising rapidly** but have not yet reached their peak. - While detectable and increasing, the concentration of hCG is significantly lower than what is observed at 9-10 weeks. *100 to 120 days after pregnancy* - By this time (approximately 14-17 weeks gestation), **hCG levels have already peaked** and are typically declining to a lower, somewhat stable plateau for the remainder of the pregnancy. - This period is well past the peak hCG concentration. *10 to 12 days after pregnancy* - This period roughly corresponds to the time of **implantation** and the very early stages of hCG production, making levels **relatively low** but detectable. - HCG levels are just beginning their rapid ascent following implantation and are far from their peak concentration.

Question 243: The placenta synthesizes all EXCEPT:

A. Oestriol
B. Dehydroepiandrosterone (Correct Answer)
C. Corticotrophin releasing hormone
D. PAPP-A (Pregnancy Associated Plasma Protein A)

Explanation: ***Dehydroepiandrosterone*** - **Dehydroepiandrosterone (DHEA)** is primarily synthesized in the **adrenal cortex** of both the fetus and the mother. - The placenta primarily converts DHEA into other steroids, such as **estrogens**, rather than synthesizing DHEA itself. *Oestriol* - The placenta plays a crucial role in synthesizing **oestriol**, particularly by utilizing **androgen precursors** from the fetal adrenal gland. - This synthesis is a key indicator of **feto-placental unit** well-being. *Corticotrophin releasing hormone* - The placenta extensively synthesizes **Corticotropin-releasing hormone (CRH)**, which gradually increases throughout pregnancy. - Placental CRH is thought to be involved in the **timing of parturition** and the regulation of fetal adrenal development. *PAPP-A (Pregnancy Associated Plasma Protein A)* - **PAPP-A** is a glycoprotein synthesized by the **syncytiotrophoblast** cells of the placenta. - It serves as an important biochemical marker in **combined first-trimester screening** for chromosomal abnormalities like Down syndrome.

Question 244: Which hormone is secreted by the placenta?

A. GnRH
B. FSH
C. hCG (Correct Answer)
D. LH

Explanation: ***hCG*** - **Human Chorionic Gonadotropin (hCG)** is produced by the **syncytiotrophoblast** of the placenta shortly after implantation. - Its primary role is to maintain the **corpus luteum**, ensuring continued production of **progesterone** to support the pregnancy. *GnRH* - **Gonadotropin-releasing hormone (GnRH)** is secreted by the **hypothalamus** in the brain, not the placenta. - It stimulates the pituitary gland to release FSH and LH. *FSH* - **Follicle-stimulating hormone (FSH)** is produced by the **anterior pituitary gland**. - It plays a crucial role in ovarian follicular development in females and spermatogenesis in males. *LH* - **Luteinizing hormone (LH)** is also secreted by the **anterior pituitary gland**. - Its functions include triggering ovulation in females and stimulating testosterone production in males.

Question 245: Which of the following is false regarding management of diabetes in pregnancy?

A. In active labor, if RBS <70 mg/dL, D5 is started at 100-150 ml/hr till the RBS is >70 mg/dL
B. In a patient being planned for induction of labor, night dose of intermediate insulin is given as planned, and the morning dose is withheld
C. Elective C-section has no role in reducing incidence of brachial plexus injury (Correct Answer)
D. Capillary blood glucose monitoring levels are kept at fasting- 95 mg/dL; 1 hr postprandial- 140 mg/dL; 2 hrs postprandial- 120 mg/dL

Explanation: ***Elective C-section has no role in reducing incidence of brachial plexus injury*** - This statement is **false** because **elective C-section** can significantly reduce the incidence of **brachial plexus injury** (BPI), especially in cases of suspected fetal macrosomia. - While not universally recommended for all diabetic pregnancies, an elective C-section is considered when the estimated **fetal weight** is substantial or when there's a history of **shoulder dystocia** to prevent birth trauma. *In active labor, if RBS <70 mg/dL, D5 is started at 100-150 ml/hr till the RBS is >70 mg/dL* - This is a **correct** management strategy for **hypoglycemia in labor**. Maintaining stable blood glucose levels (above 70 mg/dL) is crucial to prevent adverse outcomes for both mother and fetus. - The administration of **D5 (dextrose 5% in water)** intravenous solution at a specific rate helps to quickly raise and maintain blood glucose levels. *In a patient being planned for induction of labor, night dose of intermediate insulin is given as planned, and the morning dose is withheld* - This is a common and generally **correct** practice for insulin management before **induction of labor**. The night dose of intermediate insulin helps maintain basal glucose levels overnight. - Withholding the morning dose prevents **hypoglycemia** during labor when food intake is restricted, and insulin sensitivity may increase. Glucose is then typically supplemented through IV fluids as needed. *Capillary blood glucose monitoring levels are kept at fasting- 95 mg/dL; 1 hr postprandial- 140 mg/dL; 2 hrs postprandial- 120 mg/dL* - These are the generally accepted and **correct** target blood glucose levels for **diabetes in pregnancy** (both pre-existing and gestational diabetes). - Achieving these targets is essential to minimize the risk of **fetal macrosomia**, **neonatal hypoglycemia**, and other adverse perinatal outcomes.

Question 246: hCG is secreted by?

A. Cytotrophoblast
B. Yolk sac
C. Decidua
D. Syncytiotrophoblast (Correct Answer)

Explanation: ***Syncytiotrophoblast*** - The **syncytiotrophoblast** is the outer layer of the trophoblast that invades the uterine wall and is responsible for producing human chorionic gonadotropin (**hCG**). - Production of **hCG** by the **syncytiotrophoblast** begins shortly after implantation and is crucial for maintaining the **corpus luteum** and thus **progesterone** secretion during early pregnancy. *Cytotrophoblast* - The **cytotrophoblast** is the inner layer of the trophoblast that proliferates and differentiates into the **syncytiotrophoblast**. - While essential for placental development, the **cytotrophoblast** itself does not directly secrete **hCG**. *Yolk sac* - The **yolk sac** is involved in early nourishment of the embryo and plays a role in the formation of **primitive blood cells** and **germ cells**. - It does not produce **hCG**; its main functions are related to nutrition and hematopoiesis before the placenta is fully functional. *Decidua* - The **decidua** is the modified endometrial lining of the uterus during pregnancy, derived from **maternal tissue**. - It does not produce **hCG** as it is maternal in origin, whereas **hCG** is produced by fetal-derived **trophoblastic cells**.

Question 247: Beta-hCG is secreted by:

A. Yolk sac
B. Syncytiotrophoblast (Correct Answer)
C. Liver
D. Umbilical cord

Explanation: ***Syncytiotrophoblast*** - The **syncytiotrophoblast** is the outer layer of the trophoblast that surrounds the blastocyst and later the chorionic villi. - It is responsible for the secretion of various hormones, including **beta-hCG**, which is crucial for maintaining the corpus luteum and pregnancy. *Yolk sac* - The **yolk sac** is involved in early nutrient transfer, hematopoiesis, and germ cell formation. - It does not produce **beta-hCG**. *Liver* - The **liver** is a major organ of metabolism, detoxification, and protein synthesis. - It does not produce **beta-hCG**, which is specific to pregnancy. *Umbilical cord* - The **umbilical cord** connects the fetus to the placenta, facilitating nutrient and oxygen exchange. - It does not have endocrine functions and does not secrete **beta-hCG**.

Question 248: Corpus luteum in pregnancy is maintained by which hormone?

A. LH
B. FSH
C. hCG (Correct Answer)
D. Progesterone

Explanation: ***hCG (Human Chorionic Gonadotropin)*** - **hCG** is produced by the **syncytiotrophoblast** of the developing embryo shortly after implantation - It acts as an **LH analog**, binding to LH receptors on the corpus luteum - hCG **rescues the corpus luteum** from degeneration, maintaining progesterone production throughout early pregnancy - The corpus luteum remains functional until approximately **10-12 weeks of gestation**, when the placenta takes over steroidogenesis - This is the **correct answer** for maintenance of corpus luteum **in pregnancy** *LH (Luteinizing Hormone)* - LH maintains the corpus luteum in **non-pregnant menstrual cycles** for approximately 14 days - In **pregnancy**, LH levels actually **decline** and hCG takes over this function - While LH is responsible for initial corpus luteum formation and function, it does **not** maintain the corpus luteum during pregnancy *FSH (Follicle-Stimulating Hormone)* - FSH primarily stimulates **follicular development and maturation** in the ovary - It has **no direct role** in corpus luteum maintenance in either pregnant or non-pregnant states *Progesterone* - Progesterone is the **product** secreted by the corpus luteum, not the hormone that maintains it - It is essential for maintaining the **decidualized endometrium** and supporting early pregnancy - Progesterone does not act to maintain the corpus luteum itself

Question 249: A pregnant woman comes to OPD for regular ANC checkup. She gives history of previous child diagnosed with congenital adrenal hyperplasia. What drug is given in this pregnancy to prevent development of CAH in this child?

A. Hydrocortisone
B. Betamethasone
C. Dexamethasone (Correct Answer)
D. Prednisolone

Explanation: ***Dexamethasone*** - **Dexamethasone** is given to pregnant women with a previous child affected by CAH to help prevent the development of **congenital adrenal hyperplasia** (specifically **21-hydroxylase deficiency**, the most common form) in the fetus. - Treatment must be started **early in pregnancy (ideally before 9 weeks gestation)** to be effective in preventing virilization in affected female fetuses. - **Dexamethasone** crosses the placenta efficiently and suppresses fetal adrenal androgen production, which can reduce or prevent **virilization** in affected female fetuses. - It is the preferred corticosteroid for prenatal treatment due to its ability to cross the placenta without being inactivated. *Hydrocortisone* - **Hydrocortisone** is a glucocorticoid that is often used to replace cortisol in individuals with CAH after birth, but it is not typically used for prenatal prevention. - Its shorter half-life and higher mineralocorticoid activity make it less suitable for transplacental suppression compared to dexamethasone. - Additionally, it does not cross the placenta as effectively as dexamethasone. *Betamethasone* - **Betamethasone** is primarily used in pregnancy to accelerate fetal lung maturation in cases of anticipated preterm birth. - While it is a long-acting corticosteroid that can cross the placenta, it does not have the specific indication or established efficacy for preventing CAH development prenatally. *Prednisolone* - **Prednisolone** is used for various inflammatory and autoimmune conditions, and while it's a corticosteroid, it is largely **inactivated by placental 11β-hydroxysteroid dehydrogenase type 2** before reaching the fetus. - This placental inactivation (approximately 90% is converted to inactive prednisolone) makes it ineffective for suppressing fetal adrenal androgen production to prevent CAH.

Question 250: In a pregnant woman with hyperemesis gravidarum and abnormal thyroid function tests showing hyperthyroidism, which hormone is likely elevated?

A. Estradiol
B. hCG (Correct Answer)
C. Progesterone
D. TSH

Explanation: ***hCG*** - Elevated levels of **human chorionic gonadotropin (hCG)** are strongly associated with **hyperemesis gravidarum** due to its structural similarity to **TSH**. - High hCG can bind to TSH receptors in the thyroid gland, leading to transient but significant **hyperthyroidism**. *Estradiol* - Estrogen levels do increase throughout pregnancy, but elevated **estradiol** is not primarily implicated in the direct cause of hyperemesis gravidarum or the associated transient hyperthyroidism. - While it contributes to pregnancy physiology, there's no direct pathway linking high estradiol to thyroid dysfunction in this context. *Progesterone* - **Progesterone** levels rise steadily during pregnancy to maintain the uterine lining and prevent contractions. - However, progesterone does not directly cause hyperemesis gravidarum or the thyroid function test abnormalities seen in this condition. *TSH* - In a state of **hyperthyroidism**, as suggested by positive thyroid function tests, **TSH (thyroid-stimulating hormone)** levels would typically be **suppressed or low**, not elevated. - The high hCG acts as a TSH mimetic, stimulating the thyroid directly and hence reducing pituitary TSH secretion.

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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