Endocrinology of Pregnancy Practice Questions

Q: Hypothyroidism in pregnancy causes which of the following complications?

Mental retardation. **Explanation:** **Correct Answer: C. Mental retardation** The fetal thyroid gland only begins to function and concentrate iodine around the **12th week of gestation**. Prior to this, the fetus is entirely dependent on the transplacental transfer of maternal thyroxine (T4) for brain development. Thyroid hormones are critical for neuronal migration, synaptogenesis, and myelination. Maternal hypothyroidism during this crucial window leads to irreversible neurocognitive deficits and **mental retardation** (cretinism) in the offspring. **Analysis of Incorrect Options:** * **A. Macrosomia:** This is typically associated with **Gestational Diabetes Mellitus (GDM)** due to fetal hyperinsulinemia. Hypothyroidism is more commonly associated with Low Birth Weight (LBW) or Intrauterine Growth Restriction (IUGR). * **B. Polyhydramnios:** This is associated with conditions like maternal diabetes, fetal structural anomalies (e.g., esophageal atresia), or multiple gestations. Hypothyroidism is more likely to be associated with **Oligohydramnios** if it leads to placental insufficiency. * **D. Abortion:** While severe untreated hypothyroidism *can* increase the risk of early pregnancy loss, it is a non-specific complication. In the context of NEET-PG questions, **Mental Retardation** is the "hallmark" and most specific developmental consequence emphasized for maternal hypothyroidism. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Levothyroxine is the treatment of choice. * **Dose Adjustment:** Requirements of Levothyroxine increase by **30-50%** during pregnancy. * **Target TSH:** Ideally kept <2.5 mIU/L in the first trimester and <3.0 mIU/L in the second and third trimesters. * **Screening:** Universal screening for thyroid dysfunction in pregnancy is currently recommended in India due to the high prevalence of iodine deficiency.

Q: A mother presented with complaints of anxiety, intolerance to heat, fatigue, increased appetite with minimal weight gain, and tremor. She also has a heart rate of 100 bpm and bulging eyes. These findings suggest a hyperthyroid state. Based on the mother's condition, what is the baby most likely at risk for developing?

Heart failure. **Explanation:** The clinical presentation of anxiety, heat intolerance, tremors, tachycardia, and **exophthalmos (bulging eyes)** strongly indicates **Graves' disease**. In Graves' disease, the body produces **Thyroid Stimulating Immunoglobulins (TSI)**. These are IgG antibodies that can cross the placenta and stimulate the fetal thyroid gland, leading to **Neonatal Thyrotoxicosis**. **1. Why Heart Failure is Correct:** Excessive thyroid hormone in the fetus/neonate causes a hypermetabolic state and severe tachycardia. This high-output state can lead to **fetal or neonatal heart failure**, hydrops fetalis, and even intrauterine growth restriction (IUGR). In the neonate, this manifests as tachycardia, irritability, poor weight gain, and potentially fatal cardiac failure if untreated. **2. Why Incorrect Options are Wrong:** * **Constipation:** This is a feature of *hypothyroidism*. Neonatal thyrotoxicosis causes increased bowel frequency or diarrhea. * **Third-degree heart block:** This is classically associated with **Neonatal Lupus**, caused by the transplacental passage of anti-Ro (SSA) and anti-La (SSB) antibodies, not hyperthyroidism. * **Macrocephaly:** Hyperthyroidism is more likely to cause **craniosynostosis** (premature closure of sutures) and microcephaly rather than macrocephaly. **Clinical Pearls for NEET-PG:** * **TSI (Thyroid Stimulating Immunoglobulins):** The specific antibody responsible for Graves' disease that crosses the placenta. * **Treatment:** Propylthiouracil (PTU) is preferred in the 1st trimester (due to Methimazole's association with *Aplasia Cutis*); Methimazole is preferred in the 2nd and 3rd trimesters. * **Fetal Goiter:** Can occur due to either uncontrolled maternal hyperthyroidism or over-treatment with anti-thyroid drugs (which also cross the placenta).

Q: What is the treatment of choice for prenatal congenital adrenal hyperplasia?

Dexamethasone. **Explanation:** The primary goal of prenatal treatment for **Congenital Adrenal Hyperplasia (CAH)**, specifically 21-hydroxylase deficiency, is to prevent the **virilization of a female fetus** by suppressing the fetal pituitary-adrenal axis. **1. Why Dexamethasone is the Correct Answer:** Dexamethasone is a potent glucocorticoid that **crosses the placenta** without being inactivated by the placental enzyme **11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2)**. By reaching the fetal circulation, it suppresses fetal ACTH secretion, thereby reducing the production of adrenal androgens that cause ambiguous genitalia in female fetuses. Treatment must be started empirically before the 9th week of gestation (ideally by the 6th week) to be effective. **2. Why Other Options are Incorrect:** * **Hydrocortisone and Prednisolone:** These are the drugs of choice for treating CAH *postnatally* or managing the mother. However, they are extensively metabolized/inactivated by placental 11β-HSD2 and do not reach the fetus in therapeutic concentrations. * **Betamethasone:** While it also crosses the placenta, it is primarily used for inducing fetal lung maturity in preterm labor. Dexamethasone is the established gold standard for prenatal CAH suppression in clinical protocols. **Clinical Pearls for NEET-PG:** * **Timing:** Treatment must start **before 9 weeks** (before sexual differentiation begins). * **Diagnosis:** If the fetus is later confirmed to be male or an unaffected female via CVS or amniocentesis, dexamethasone is discontinued. * **Maternal Side Effects:** Long-term dexamethasone use can cause maternal weight gain, striae, and gestational diabetes. * **Enzyme Deficiency:** 21-hydroxylase deficiency is the most common cause (90-95%) of CAH.

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: 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: Which hormone is responsible for the decidual reaction and Arias-Stella reaction in ectopic pregnancy?

Progesterone. **Explanation:** The correct answer is **Progesterone**. In an ectopic pregnancy, the body produces hormones similar to a normal intrauterine pregnancy. **Progesterone**, secreted by the corpus luteum, is the primary hormone responsible for the structural transformation of the endometrium into the **decidua**. This "decidual reaction" occurs even if the blastocyst is implanted outside the uterus because the endometrium responds to circulating systemic hormones rather than local implantation. The **Arias-Stella reaction** is a specific histological change characterized by hypertrophic, hyperchromatic, and enlarged endometrial glandular nuclei. It is a benign response of the endometrial glands to high levels of progesterone. While most commonly associated with ectopic pregnancy, it is not pathognomonic as it can also be seen in intrauterine pregnancies or with trophoblastic disease. **Analysis of Incorrect Options:** * **Estrogen (A):** While estrogen causes endometrial proliferation, it does not induce the secretory changes or the specialized decidualization required for these reactions. * **hCG (C):** Human Chorionic Gonadotropin maintains the corpus luteum, which in turn produces progesterone. Thus, hCG is an indirect cause, but progesterone is the direct effector hormone on the endometrium. * **hPL (D):** Human Placental Lactogen is involved in fetal growth and maternal metabolism (anti-insulin effect) and has no role in the decidual reaction. **NEET-PG High-Yield Pearls:** * **Decidual Cast:** If the ectopic pregnancy fails, the sudden drop in progesterone leads to the sloughing of the entire decidua as a single triangular piece, known as a decidual cast. * **Arias-Stella Reaction:** It can be mistaken for clear cell carcinoma or endoadenocarcinoma due to its hyperchromatic nuclei; however, the lack of mitosis helps in differentiation. * **Triad of Ectopic Pregnancy:** Amenorrhea, abdominal pain, and vaginal bleeding.

Q: Which of the following changes occurs in pregnancy?

Plasma fibrinogen levels are increased. **Explanation:** Pregnancy is characterized by significant physiological adaptations to prepare for the challenges of delivery, most notably the risk of postpartum hemorrhage. **1. Why Option A is Correct:** Pregnancy induces a **hypercoagulable state**. There is a marked increase in several clotting factors, most significantly **Fibrinogen (Factor I)**. Plasma fibrinogen levels rise by approximately 50%, increasing from non-pregnant levels of 200–400 mg/dL to **400–600 mg/dL** by the third trimester. This serves as a protective mechanism to facilitate rapid hemostasis during placental separation. **2. Why the Other Options are Incorrect:** * **Option B:** Fibrinogen levels **increase**, not decrease. A "normal" non-pregnant fibrinogen level in a pregnant woman (e.g., <200 mg/dL) may actually indicate a pathological state like DIC or abruptio placentae. * **Option C:** Estrogen stimulates the liver to increase the production of **Thyroxine-Binding Globulin (TBG)**. Consequently, total T3 and T4 levels increase, though free T3 and T4 remain largely unchanged (euthyroid state). * **Option D:** While there are complex immunological shifts (moving toward a Th2-mediated response to protect the fetus), **IgD levels remain unchanged** or may slightly decrease. There is no "marked increase" in IgD during pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **Coagulation:** Factors VII, VIII, IX, X, and XII also increase. However, **Factors XI and XIII decrease**. * **Anticoagulants:** Protein S levels decrease, and there is increased resistance to Activated Protein C (APC). * **ESR:** Due to the rise in fibrinogen, the **Erythrocyte Sedimentation Rate (ESR) increases** significantly in pregnancy, making it an unreliable marker for infection. * **Platelets:** There is a slight decrease in platelet count due to hemodilution and increased consumption (Gestational Thrombocytopenia).

Q: A class C diabetic patient delivers at term. It is important to check her blood sugar levels immediately postpartum, as there may be a decrease in the insulin requirements of diabetic patients. This can be partly explained by:

Decrease in plasma chorionic somatomammotropin. ### Explanation **1. Why Option C is Correct:** The primary reason for the precipitous drop in insulin requirements immediately postpartum is the **removal of the placenta**. During pregnancy, the placenta produces several "diabetogenic" hormones, the most potent being **Human Placental Lactogen (hPL)**, also known as **Human Chorionic Somatomammotropin (hCS)**. hCS induces peripheral insulin resistance and increases lipolysis to ensure a steady glucose supply to the fetus. Once the placenta is delivered, the levels of hCS (along with placental growth hormone, cortisol, and progesterone) drop rapidly. This sudden withdrawal of insulin-antagonistic hormones restores maternal insulin sensitivity, often leading to a "honeymoon period" where insulin requirements may fall to 50% of pre-pregnancy doses or even zero temporarily. **2. Why Other Options are Incorrect:** * **Option A (Increased food intake):** Increased caloric intake would typically *increase* the need for insulin, not decrease it. * **Option B (Decreased activity):** Physical inactivity generally increases insulin resistance and blood glucose levels, which would necessitate *more* insulin, not less. **3. Clinical Pearls for NEET-PG:** * **The "Diabetogenic" State:** Pregnancy is naturally a state of insulin resistance, peaking in the **3rd trimester** due to hCS. * **Postpartum Management:** In Type 1 DM, insulin dosage should be reduced immediately to roughly **half of the end-of-pregnancy dose** to avoid hypoglycemia. * **GDM Follow-up:** Patients with Gestational Diabetes (GDM) should undergo a **75g OGTT at 6–12 weeks postpartum** to screen for persistent Type 2 Diabetes. * **hCS Function:** It is structurally similar to Growth Hormone and Prolactin; its primary role is maternal metabolic adaptation to ensure fetal nutrition.

Q: What is the typical pH of the vagina during pregnancy?

4.5. **Explanation:** The correct answer is **A. 4.5**. During pregnancy, the vaginal environment becomes significantly more acidic, typically ranging from **3.5 to 6.0**. This change is driven by high levels of circulating **estrogen**, which increases the deposition of **glycogen** in the vaginal squamous epithelium. *Lactobacillus acidophilus* (Döderlein’s bacilli) ferments this glycogen into **lactic acid**, thereby lowering the pH. This acidic environment serves as a critical innate immune mechanism, inhibiting the growth of pathogenic bacteria and protecting both the mother and the fetus from ascending infections. **Analysis of Incorrect Options:** * **B (7.0):** This is a neutral pH. A neutral or alkaline pH in the vagina is abnormal and often seen in conditions like Bacterial Vaginosis (pH > 4.5) or Trichomoniasis. * **C (8.5) & D (11.0):** These are strongly alkaline values. Such high pH levels are not physiological in the human vagina and would indicate severe pathology or the presence of amniotic fluid (which is alkaline, pH 7.0–7.5), often used as a diagnostic marker for Premature Rupture of Membranes (PROM) via the Nitrazine test. **High-Yield Clinical Pearls for NEET-PG:** * **Glycogen & Estrogen:** Estrogen → ↑ Glycogen → ↑ Lactic Acid (via Lactobacilli) → ↓ pH. * **Amniotic Fluid:** It is alkaline (pH 7.0–7.5). A shift from acidic to alkaline pH in the vagina is a classic sign of **PROM**. * **Infection Screening:** A vaginal pH > 4.5 in a non-pregnant or pregnant woman is a primary screening criterion for **Bacterial Vaginosis** (Amsel's Criteria). * **Candidiasis:** Unlike other infections, the vaginal pH remains **normal (< 4.5)** in Vulvovaginal Candidiasis.

Question 1

Hypothyroidism in pregnancy causes which of the following complications?

Accepted Answer

Mental retardation

Answer

Macrosomia

Answer

Polyhydramnios

Answer

Abortion

Question 2

A mother presented with complaints of anxiety, intolerance to heat, fatigue, increased appetite with minimal weight gain, and tremor. She also has a heart rate of 100 bpm and bulging eyes. These findings suggest a hyperthyroid state. Based on the mother's condition, what is the baby most likely at risk for developing?

Accepted Answer

Heart failure

Answer

Constipation

Answer

Third-degree heart block

Answer

Macrocephaly

Question 3

What is the treatment of choice for prenatal congenital adrenal hyperplasia?

Accepted Answer

Dexamethasone

Answer

Hydrocortisone

Answer

Betamethasone

Answer

Prednisolone

Question 4

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 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

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 7

Which hormone is responsible for the decidual reaction and Arias-Stella reaction in ectopic pregnancy?

Accepted Answer

Progesterone

Answer

Estrogen

Answer

hCG

Answer

hPL

Question 8

Which of the following changes occurs in pregnancy?

Accepted Answer

Plasma fibrinogen levels are increased

Answer

Fibrinogen levels are decreased

Answer

Thyroglobulins are decreased

Answer

IgD are markedly increased

Question 9

A class C diabetic patient delivers at term. It is important to check her blood sugar levels immediately postpartum, as there may be a decrease in the insulin requirements of diabetic patients. This can be partly explained by:

Accepted Answer

Decrease in plasma chorionic somatomammotropin

Answer

Increased food intake

Answer

Decreased activity

Answer

All of the above

Question 10

What is the typical pH of the vagina during pregnancy?

Accepted Answer

4.5

Answer

7.0

Answer

8.5

Answer

11.0

Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy — MCQs

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