Placental Hormones — MCQs
The role of human placental lactogen is :
In a case of molar pregnancy, the most important marker for monitoring response to treatment is:
hCG is secreted by?
Which of the following statements about placental hormones is true?
Which of the following C-21 steroid hormones is primarily associated with reproductive health?
What maternal condition is commonly associated with congenital heart defects in the fetus?
Which hormone is primarily responsible for insulin resistance during pregnancy?
Which of the following is the marker of ovarian reserve?
The placenta synthesizes all EXCEPT:
In a pregnant woman with hyperemesis gravidarum and abnormal thyroid function tests showing hyperthyroidism, which hormone is likely elevated?
Placental Hormones Indian Medical PG Practice Questions and MCQs
Question 1: The role of human placental lactogen is :
- A. Stimulate milk production
- B. Promotes growth of breast for lactation.
- C. Supports fetal growth and development. (Correct Answer)
- D. Provide fetal nutrition by antagonizing the action of insulin in maternal circulation, breakdown of fats and proteins and transport of fatty acids and amino acids from maternal to fetal circulation.
Explanation: ***Supports fetal growth and development.*** - Human placental lactogen (hPL) acts as a **growth hormone** for the fetus, primarily by altering maternal metabolism to favor fetal nutrient supply. - It increases **maternal insulin resistance**, leading to higher maternal glucose and free fatty acids, which are then shunted to the fetus, supporting its growth and development. *Stimulate milk production* - **Prolactin**, secreted by the anterior pituitary, is the primary hormone responsible for stimulating milk production (lactogenesis). - While hPL has some structural similarity to growth hormone and prolactin, its primary role is not to directly stimulate milk production during pregnancy; rather, it prepares the breasts. *Promotes growth of breast for lactation.* - hPL, along with **estrogen** and **progesterone**, contributes to the **mammary gland development** during pregnancy, preparing the breasts for lactation. - However, its direct role is more about **mammary gland proliferation and differentiation** rather than initiation of milk production. *Provide fetal nutrition by antagonizing the action of insulin in maternal circulation, breakdown of fats and proteins and transport of fatty acids and amino acids from maternal to fetal circulation.* - This is a highly detailed and largely accurate description of *how* hPL supports fetal growth and development, making it a mechanism rather than the primary, concise role. - It describes the metabolic changes induced by hPL, which ultimately lead to the **support of fetal growth and development**.
Question 2: In a case of molar pregnancy, the most important marker for monitoring response to treatment is:
- A. Serum CA-125
- B. Serum estriol
- C. Serum AFP
- D. Serum hCG (Correct Answer)
Explanation: ***Serum hCG*** - **Human chorionic gonadotropin (hCG)** is produced by the trophoblastic tissue, which is overproliferated in molar pregnancies. - Monitoring **serial hCG levels** post-evacuation is the **gold standard** for detecting persistent trophoblastic disease or malignant transformation. - A rise or plateau in hCG levels indicates inadequate treatment or recurrence, requiring chemotherapy. - **Clinical protocol**: Weekly hCG monitoring until three consecutive negative results, then monthly for 6 months (FIGO guidelines). *Serum CA-125* - **CA-125** is primarily a marker for ovarian cancer and certain benign gynecologic conditions like endometriosis. - It is not a reliable marker for monitoring the response to treatment in **molar pregnancies**. *Serum estriol* - **Estriol** is a hormone produced by the placenta and fetal adrenal gland, primarily used to monitor fetal well-being during pregnancy. - It has no role in the diagnosis or monitoring of **molar pregnancies**. *Serum AFP* - **Alpha-fetoprotein (AFP)** is a tumor marker for certain germ cell tumors, liver cancer, and is also used in prenatal screening for neural tube defects. - It is not associated with the pathogenesis or monitoring of **molar pregnancies**.
Question 3: 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 4: 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 5: Which of the following C-21 steroid hormones is primarily associated with reproductive health?
- A. Corticosterone
- B. Cortisol
- C. Aldosterone
- D. Progesterone (Correct Answer)
Explanation: ***Progesterone*** - **Progesterone** is a C-21 steroid hormone primarily involved in the **menstrual cycle**, **pregnancy**, and **embryogenesis**, making it crucial for female reproductive health. - It prepares the **endometrium** for the implantation of a fertilized egg and helps maintain pregnancy by preventing uterine contractions. *Cortisol* - **Cortisol** is a **glucocorticoid** primarily involved in stress response, metabolism, and immune function. - While it has broad effects, its main role is not directly associated with reproductive health. *Aldosterone* - **Aldosterone** is a **mineralocorticoid** that regulates **blood pressure** and **electrolyte balance** by controlling sodium and potassium levels. - It plays no direct role in reproductive health. *Corticosterone* - **Corticosterone** is a **glucocorticoid** and a precursor to aldosterone, mainly involved in stress response in some animals, similar to cortisol. - It is not a primary hormone for human reproductive health.
Question 6: What maternal condition is commonly associated with congenital heart defects in the fetus?
- A. ACE inhibitor
- B. GDM
- C. Pregestational DM (Correct Answer)
- D. Valproate
Explanation: ***Pregestational DM*** - **Pre-existing diabetes** in the mother is a significant risk factor for various **congenital anomalies**, including **congenital heart defects**, due to suboptimal glycemic control during early embryogenesis. - Poorly controlled **maternal hyperglycemia** leads to increased oxidative stress and altered cellular metabolism in the developing fetus, impacting cardiovascular development. *ACE inhibitor* - **ACE inhibitors** are teratogenic, primarily causing **renal dysfunction** (e.g., renal tubular dysplasia, oligohydramnios, anuria) and **fetal growth restriction**, especially when used in the second and third trimesters. - While they can have adverse fetal effects, their association with **congenital heart defects** is less pronounced compared to other teratogenic exposures. *GDM* - **Gestational diabetes mellitus (GDM)** typically develops in the second or third trimester when major organogenesis is complete, making its association with **structural congenital anomalies**, including heart defects, significantly lower than pregestational diabetes. - GDM is more commonly associated with fetal **macrosomia**, **hypoglycemia**, and respiratory distress syndrome at birth. *Valproate* - **Valproate** is a known teratogen associated with a specific pattern of anomalies, most notably **neural tube defects** (e.g., spina bifida), and facial dysmorphisms. - While it can be associated with an increased risk of some congenital heart defects, its primary and most significant fetal risk is **neural tube defects**.
Question 7: Which hormone is primarily responsible for insulin resistance during pregnancy?
- A. Estrogen
- B. HPL (Correct Answer)
- C. Progesterone
- D. GH
Explanation: ***HPL*** - **Human placental lactogen (HPL)**, also known as **chorionic somatomammotropin**, directly induces maternal insulin resistance to ensure a continuous supply of glucose to the fetus. - HPL levels rise throughout pregnancy, peaking in the third trimester, correlating with increasing insulin resistance. *Estrogen* - While **estrogen** levels are high in pregnancy, its primary role is in supporting uterine growth and maintaining the pregnancy, not directly causing significant insulin resistance. - High estrogen levels can enhance insulin sensitivity in some contexts, contrasting with the overall insulin resistance of pregnancy. *Progesterone* - **Progesterone** is crucial for maintaining pregnancy and relaxing smooth muscle but does not directly cause the marked insulin resistance seen in gestation. - It works synergistically with other hormones but is not the primary driver of glucose intolerance in pregnancy. *GH* - **Growth hormone (GH)** does contribute to insulin resistance in non-pregnant individuals and at high levels can cause insulin resistance, but it is not the primary hormone responsible for the unique physiological insulin resistance of pregnancy. - While GH is present, **HPL** is the dominant somatotropic hormone of pregnancy directly impacting glucose metabolism.
Question 8: Which of the following is the marker of ovarian reserve?
- A. β-hCG
- B. Anti-Mullerian hormone (Correct Answer)
- C. Placental alkaline phosphatase
- D. Serum estradiol
Explanation: ***Anti-Mullerian hormone*** - **Anti-Mullerian hormone (AMH)** is produced by the granulosa cells of small antral and pre-antral follicles in the ovary. - AMH levels correlate with the size of the **primordial follicle pool**, making it the **most reliable indicator of ovarian reserve**. - Unlike other markers, AMH remains relatively **constant throughout the menstrual cycle** and can be measured on any day. - AMH is the **preferred marker** in fertility assessment and IVF planning. *β-hCG* - **Beta-human chorionic gonadotropin (β-hCG)** is a hormone produced during pregnancy by the developing placenta. - Its presence indicates pregnancy and is not a marker for **ovarian reserve**. *Placental alkaline phosphatase* - **Placental alkaline phosphatase (PLAP)** is an enzyme produced by the placenta. - It serves as a biological marker for certain cancers (e.g., germ cell tumors) and sometimes for placental function, but not **ovarian reserve**. *Serum estradiol* - **Serum estradiol** levels fluctuate significantly throughout the menstrual cycle and are influenced by numerous factors. - While **Day 3 estradiol** combined with FSH was historically used for ovarian reserve assessment, elevated levels can indicate poor reserve (due to early follicular recruitment). - However, it is **not as reliable or cycle-independent as AMH** for assessing the overall **follicle pool**.
Question 9: 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 10: 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.
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