Endocrinology of Pregnancy Practice Questions

Q: Which of the following substances is present in a higher concentration in the mother compared to the fetus?

Human placental lactogen (HPL). **Explanation:** The correct answer is **Human placental lactogen (HPL)**. **1. Why HPL is the correct answer:** Human Placental Lactogen (also known as Human Chorionic Somatomammotropin) is synthesized by the **syncytiotrophoblast** of the placenta. It is primarily secreted into the **maternal circulation**, where its levels rise progressively throughout pregnancy, reaching a peak near term. Its main function is to induce maternal insulin resistance to ensure a steady supply of glucose for the fetus. Because it is secreted directly into maternal blood and has a large molecular weight, its concentration is significantly higher in the mother than in the fetus (maternal levels are roughly 100–1000 times higher). **2. Why the other options are incorrect:** * **Iron (B):** Iron is actively transported across the placenta via transferrin receptors. The fetus acts as a "parasite" for iron, maintaining higher serum ferritin and iron levels than the mother, even if the mother is anemic. * **Zinc (A) and Ascorbic acid (C):** Most water-soluble vitamins (like Vitamin C/Ascorbic acid) and essential minerals (like Zinc and Calcium) are transported via **active transport** against a concentration gradient. Consequently, their concentrations are higher in the fetal circulation than in the maternal circulation. **3. NEET-PG High-Yield Pearls:** * **Higher in Fetus:** Iron, Calcium, Amino acids, Water-soluble vitamins (B & C), and Glucose (though glucose moves by *facilitated diffusion*, fetal levels are high, but technically slightly lower than maternal levels; however, minerals and vitamins are strictly higher in the fetus). * **Higher in Mother:** HPL, HCG, Fat-soluble vitamins (A, D, E, K), and Free Fatty Acids. * **HPL Clinical Note:** HPL is the most potent "diabetogenic" hormone of pregnancy and is the primary reason for the increased insulin requirement in pregnant women.

Q: A primigravida at 10 weeks gestation, with pre-existing diabetes managed on insulin, has been hospitalized for ketoacidosis. Which of the following is the most probable cause for her ketoacidosis?

Hyperemesis gravidarum. **Explanation:** In early pregnancy, **Hyperemesis Gravidarum (HG)** is a classic trigger for Diabetic Ketoacidosis (DKA) in women with pre-existing Type 1 Diabetes. The underlying mechanism involves severe vomiting leading to **starvation ketosis**, dehydration, and electrolyte imbalances. The resulting carbohydrate deprivation forces the body to metabolize fats for energy, producing ketones. In a diabetic patient, this metabolic stress, combined with the inability to maintain oral intake and potential disruption of insulin dosing, rapidly escalates into DKA. **Analysis of Options:** * **Option A (Infection):** While infection is the most common cause of DKA in late pregnancy or non-pregnant states, the clinical context of a primigravida at **10 weeks** (peak hCG levels) strongly points toward HG as the primary culprit. * **Option C (Folic Acid):** Folic acid deficiency is associated with neural tube defects but has no physiological link to glycemic control or ketosis. * **Option D (Pancreatitis):** Though it can cause DKA, it is a much rarer complication in the first trimester compared to the high prevalence of pregnancy-related vomiting. **High-Yield NEET-PG Pearls:** 1. **Lower Threshold:** DKA in pregnancy occurs at lower blood glucose levels (often <200 mg/dL), a phenomenon known as **Euglycemic DKA**, due to the "accelerated starvation" state of pregnancy. 2. **Hormonal Influence:** Human Placental Lactogen (hPL), which increases insulin resistance, peaks in the third trimester; however, HG is the dominant metabolic challenge in the **first trimester**. 3. **Fetal Risk:** DKA is a medical emergency with a high risk of fetal demise (up to 10-30%).

Q: A female with a previous child diagnosed with congenital adrenal hyperplasia requires steroid therapy in the present pregnancy. When should this therapy be initiated?

As soon as pregnancy is diagnosed. **Explanation:** The primary goal of prenatal treatment in Congenital Adrenal Hyperplasia (CAH), specifically 21-hydroxylase deficiency, is to **prevent the virilization of a female fetus**. 1. **Why Option D is correct:** The development of external genitalia begins around the **6th to 7th week** of gestation. To effectively suppress the fetal pituitary-adrenal axis and prevent the overproduction of adrenal androgens, dexamethasone must be initiated **before** this critical window. Since the diagnosis of the fetal sex and genotype cannot be confirmed that early, treatment must start **as soon as pregnancy is confirmed** (usually by the 5th–6th week) to ensure the female fetus is protected from masculinization. 2. **Why other options are incorrect:** * **Option A:** Karyotyping (via CVS or amniocentesis) occurs after the 10th–15th week. By this time, if the fetus is female, virilization has already occurred, making the therapy ineffective for its primary purpose. * **Option B:** Treatment at delivery is useless for preventing birth defects; it only manages the neonate's immediate metabolic crisis. * **Option C:** While pre-conception counseling is vital, steroid therapy is not required until there is a developing fetus to protect. **Clinical Pearls for NEET-PG:** * **Drug of Choice:** **Dexamethasone** (20 mcg/kg/day) is used because it is not inactivated by the placental enzyme 11β-hydroxysteroid dehydrogenase type 2, allowing it to reach the fetus. * **Management Strategy:** Treatment is started blindly in all at-risk pregnancies. Once the sex is determined (via CVS/NIPT) and the fetus is found to be **male** or an **unaffected female**, dexamethasone is discontinued. * **Risk:** Only 1 in 8 at-risk fetuses (those who are both female and affected) actually benefit from the therapy.

Q: Which of the following hormones are secreted exclusively by the placenta?

hPL. ### Explanation The correct answer is **C. hPL (Human Placental Lactogen)**. **1. Why hPL is the correct answer:** Human Placental Lactogen (hPL), also known as Human Chorionic Somatomammotropin (hCS), is synthesized and secreted **exclusively** by the syncytiotrophoblast of the placenta. It is detectable in maternal serum from the 5th week of gestation and its levels rise proportionately with placental mass. Its primary role is to ensure a continuous nutrient supply to the fetus by inducing maternal insulin resistance (diabetogenic effect). **2. Why the other options are incorrect:** * **A. hCG (Human Chorionic Gonadotropin):** While primarily a placental hormone, hCG is not "exclusive." Small amounts are secreted by the **pituitary gland** in non-pregnant individuals (especially post-menopausal women) and by certain germ cell tumors or gestational trophoblastic diseases. * **B. Estrogen:** During pregnancy, the placenta produces large amounts of estrogen (primarily Estriol). However, estrogen is also produced by the **ovaries** (corpus luteum and follicles) and peripheral tissues (via aromatization). * **C. PRL (Prolactin):** Prolactin is primarily secreted by the **anterior pituitary gland** (lactotrophs). During pregnancy, it is also produced by the **decidua** (maternal side), but it is not a placental hormone. **3. High-Yield NEET-PG Pearls:** * **hPL** is the most potent "diabetogenic" hormone of pregnancy; it is the main reason for the increased insulin requirement in pregnancy. * **hPL** levels correlate directly with **placental weight**. Low levels are seen in placental insufficiency. * **hCG** is a glycoprotein with an $\alpha$-subunit identical to LH, FSH, and TSH. The $\beta$-subunit is unique and used for pregnancy testing. * **Estriol ($E_3$)** is the dominant estrogen in pregnancy; its synthesis requires the **fetal adrenal gland** and liver, making it a marker of the feto-placental unit.

Q: All are consistent with the diabetogenic effects of pregnancy except?

Decrease lipolysis. Pregnancy is characterized by a state of **"accelerated starvation"** and **"facilitated anabolism"** to ensure a continuous supply of nutrients to the fetus. The diabetogenic effect is primarily driven by placental hormones (hPL, cortisol, progesterone) to spare glucose for the fetus. **Explanation of the Correct Answer:** * **B. Decrease lipolysis:** This is the correct answer because pregnancy actually causes **increased lipolysis**. During fasting states, the maternal body shifts toward fat metabolism to conserve glucose for the fetus. This leads to an increase in free fatty acids (FFAs) and ketones in the maternal circulation. Decreased lipolysis would be contrary to the metabolic demands of pregnancy. **Analysis of Incorrect Options:** * **A. Insulin resistance:** This is a hallmark of the second and third trimesters. Human Placental Lactogen (hPL) and TNF-alpha induce peripheral resistance to insulin, ensuring glucose remains available in the blood for placental transfer. * **C. Changes in gluconeogenesis:** Maternal hepatic glucose production increases (gluconeogenesis) to maintain a steady glucose gradient for the fetus, despite the mother’s peripheral insulin resistance. * **D. Placental insulinase:** The placenta produces the enzyme insulinase, which actively degrades maternal insulin, further contributing to the diabetogenic state. **NEET-PG High-Yield Pearls:** * **hPL (Human Placental Lactogen)** is the most potent antagonist to insulin during pregnancy. * **Fasting Hypoglycemia:** Despite insulin resistance, pregnant women develop fasting hypoglycemia because the fetus continuously drains maternal glucose. * **Post-prandial Hyperglycemia:** Due to insulin resistance, blood sugar levels stay elevated longer after meals. * **Ketosis:** Pregnant women are more prone to ketosis (starvation ketosis) due to the rapid shift to lipolysis.

Q: The pH of the normal vagina is the lowest during which of the following phases?

Pregnancy. **Explanation:** The acidity of the vaginal environment is primarily determined by the presence of **Döderlein’s bacilli** (Lactobacilli), which convert glycogen from the vaginal epithelium into **lactic acid**. **Why Pregnancy is the correct answer:** During pregnancy, there is a significant increase in estrogen levels. Estrogen promotes the thickening of the vaginal epithelium and the deposition of high amounts of **glycogen**. This abundance of substrate allows Lactobacilli to produce maximal amounts of lactic acid, causing the vaginal pH to drop to its lowest levels (typically between **3.5 and 4.5**). This acidic environment serves as a protective mechanism against ascending infections. **Analysis of Incorrect Options:** * **Menstruation:** During menses, the presence of alkaline blood and the shedding of the epithelium raise the pH toward neutral or alkaline levels (approx. 7.0), increasing the risk of infections. * **Puerperium:** Following delivery, estrogen levels drop sharply and the presence of lochia (alkaline) raises the vaginal pH. * **Infancy:** In infants (after the initial influence of maternal estrogen fades) and prepubertal girls, the vaginal epithelium is thin and lacks glycogen. The pH is typically neutral or alkaline (around 7.0). **High-Yield Clinical Pearls for NEET-PG:** * **Normal Vaginal pH:** 3.8 to 4.5 (reproductive age). * **Bacterial Vaginosis:** pH > 4.5 (Key diagnostic feature in Amsel's criteria). * **Trichomoniasis:** pH > 4.5 to 5. * **Vulvovaginal Candidiasis:** pH is typically **normal** ( 6.0 due to estrogen deficiency.

Q: In a normal pregnancy, due to physiological changes, which of the following can be observed?

Increase in blood volume by 20 to 40%. **Explanation:** **1. Why Option A is Correct:** During pregnancy, there is a significant expansion of the intravascular volume to meet the metabolic demands of the enlarging uterus and to protect the mother against the blood loss associated with delivery. The **plasma volume increases by approximately 40–50%**, while the red cell mass increases by about 20–30%. This results in an overall **increase in total blood volume by roughly 30–45%** (making Option A the most accurate choice among the provided ranges). **2. Why the Other Options are Incorrect:** * **Option B:** While **systolic** flow murmurs are common (found in >90% of pregnant women) due to increased cardiac output and decreased blood viscosity, **diastolic murmurs are always pathological** and warrant further investigation (e.g., echocardiography). * **Option C:** Although red cell mass increases, the plasma volume increases disproportionately more. This leads to **hemodilution**, resulting in a **decrease in hematocrit** and hemoglobin concentration (Physiological Anemia of Pregnancy). * **Option D:** In pregnancy, the diaphragm is elevated by about 4 cm. While the tidal volume increases (by 40%), the **vital capacity remains unchanged** or may show a very slight increase, but it certainly does not decrease significantly. **NEET-PG High-Yield Pearls:** * **Maximum increase in blood volume:** Occurs at **32–34 weeks** of gestation. * **Cardiac Output:** Increases by 30–50%, peaking immediately postpartum. * **Blood Pressure:** Diastolic BP decreases more than systolic BP, reaching its nadir in the second trimester. * **Respiratory Change:** The most significant change is an increase in **Tidal Volume**, leading to a state of compensated respiratory alkalosis.

Q: According to ACOG guidelines, what are the cut-off values in a 2-hour oral glucose tolerance test for fasting, 1-hour, and 2-hour plasma glucose levels?

95 mg/dL, 180 mg/dL, 155 mg/dL. ### Explanation The diagnosis of Gestational Diabetes Mellitus (GDM) follows two primary strategies: the **One-step** (IADPSG/WHO) and the **Two-step** (ACOG/Carpenter-Coustan) approach. **1. Why Option B is Correct:** ACOG recommends the **Two-step approach**. If a 50g Glucose Challenge Test (GCT) is positive, a diagnostic 100g, 3-hour OGTT is performed. However, for the **2-hour 75g OGTT** (often used in specific protocols or when following Carpenter-Coustan criteria adapted for 2 hours), the traditional ACOG-recognized thresholds are: * **Fasting:** 95 mg/dL * **1-hour:** 180 mg/dL * **2-hour:** 155 mg/dL Diagnosis is typically made if **two or more** values are met or exceeded. **2. Analysis of Incorrect Options:** * **Option C (92/180/153):** These are the **IADPSG (International Association of Diabetes and Pregnancy Study Groups)** criteria, also adopted by the **WHO**. This is a "One-step" 75g OGTT where only **one** abnormal value is required for diagnosis. * **Options A and D:** These represent hybrid or incorrect variations of the Carpenter-Coustan and IADPSG values, often used as distractors in exams to confuse the fasting (92 vs 95) and 2-hour (153 vs 155) cut-offs. **3. NEET-PG High-Yield Pearls:** * **Gold Standard (ACOG):** Two-step approach (50g screen $\rightarrow$ 100g diagnostic). * **DIPSI (Indian Guidelines):** A single-step 75g OGTT is performed regardless of the last meal. GDM is diagnosed if the 2-hour value is **$\geq$ 140 mg/dL**. * **Best Time for Screening:** 24–28 weeks of gestation. * **First-line Management:** Medical Nutrition Therapy (MNT) for 1–2 weeks; if targets aren't met, Insulin is the drug of choice.

Question 1

Which of the following substances is present in a higher concentration in the mother compared to the fetus?

Accepted Answer

Human placental lactogen (HPL)

Answer

Zinc

Answer

Iron

Answer

Ascorbic acid

Question 2

All of the following are true regarding the management of diabetic patients during pregnancy, EXCEPT?

Accepted Answer

A Glucose Tolerance Test (GTT) must be performed in all patients with known diabetes at the first visit.

Answer

Insulin is the most preferred drug, if required, for glycemic control.

Answer

Targeted sonography should be performed between 18 and 20 weeks to rule out fetal anomalies.

Answer

Metformin and Glyburide are oral hypoglycemics, safe for use in pregnancy.

Question 3

A primigravida at 10 weeks gestation, with pre-existing diabetes managed on insulin, has been hospitalized for ketoacidosis. Which of the following is the most probable cause for her ketoacidosis?

Accepted Answer

Hyperemesis gravidarum

Answer

Infection

Answer

Not taking regular folic acid

Answer

Pancreatitis

Question 4

A female with a previous child diagnosed with congenital adrenal hyperplasia requires steroid therapy in the present pregnancy. When should this therapy be initiated?

Accepted Answer

As soon as pregnancy is diagnosed

Answer

After karyotyping and determination of the baby's sex

Answer

At the time of delivery

Answer

Before conception

Question 5

What is the drug of choice for treating hyperthyroidism in pregnancy?

Accepted Answer

Propylthiouracil

Answer

Carbimazole

Answer

Propranolol

Answer

Lugol's iodine

Question 6

Which of the following hormones are secreted exclusively by the placenta?

Accepted Answer

hPL

Answer

hCG

Answer

Estrogen

Answer

PRL

Question 7

All are consistent with the diabetogenic effects of pregnancy except?

Accepted Answer

Decrease lipolysis

Answer

Insulin resistance

Answer

Changes in gluconeogenesis

Answer

Placental insulinase

Question 8

The pH of the normal vagina is the lowest during which of the following phases?

Accepted Answer

Pregnancy

Answer

Menstruation

Answer

Puerperium

Answer

Infancy

Question 9

In a normal pregnancy, due to physiological changes, which of the following can be observed?

Accepted Answer

Increase in blood volume by 20 to 40%

Answer

Short diastolic murmurs

Answer

Increase in hematocrit

Answer

Increase in vital capacity

Question 10

According to ACOG guidelines, what are the cut-off values in a 2-hour oral glucose tolerance test for fasting, 1-hour, and 2-hour plasma glucose levels?

Accepted Answer

95 mg/dL, 180 mg/dL, 155 mg/dL

Answer

92 mg/dL, 182 mg/dL, 155 mg/dL

Answer

92 mg/dL, 180 mg/dL, 153 mg/dL

Answer

92 mg/dL, 180 mg/dL, 155 mg/dL

Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy — MCQs

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