Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy Indian Medical PG Practice Questions and MCQs

Question 81: Maximum level of beta HCG is seen at what gestational age in weeks?

A. 8 weeks
B. 9 weeks
C. 10 weeks (Correct Answer)
D. 11 weeks

Explanation: **Explanation:** Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone produced by the syncytiotrophoblast. Its primary role is to maintain the corpus luteum, ensuring the continued production of progesterone until the placenta takes over (the luteo-placental shift). **Why 10 weeks is correct:** The levels of beta-hCG rise exponentially in early pregnancy, doubling approximately every 48 hours. The hormone reaches its **peak concentration between 8 to 12 weeks** of gestation (mean peak at **10 weeks**), reaching values of approximately 100,000 mIU/mL. After this peak, levels decline significantly and reach a stable plateau around 20 weeks, which is maintained until term. **Analysis of incorrect options:** * **8 weeks:** While hCG levels are very high at this stage, they have not yet reached their absolute zenith in a typical pregnancy. * **9 weeks:** This is within the rising phase towards the peak, but statistically, the 10th week represents the most common point of maximum concentration. * **11 weeks:** Levels may still be high, but they generally begin their downward trend toward the second-trimester plateau after the 10-week mark. **High-Yield Clinical Pearls for NEET-PG:** * **Doubling Time:** In a healthy intrauterine pregnancy, hCG levels should increase by at least 66% every 48 hours. * **Discriminatory Zone:** The level of hCG at which a gestational sac should be visible on TVS (usually 1,500–2,000 mIU/mL). * **Abnormal Levels:** Pathologically high hCG levels are seen in **Molar pregnancy** and **Multiple gestations**, while lower-than-expected levels suggest **Ectopic pregnancy** or **Spontaneous abortion**. * **Subunits:** The **alpha subunit** is identical to LH, FSH, and TSH; the **beta subunit** is unique to hCG, making it the basis for pregnancy tests.

Question 82: Which oral hypoglycemic agent is safely given in pregnancy?

A. Metformin (Correct Answer)
B. Sitagliptin
C. Glimepride
D. Pioglitazone

Explanation: **Explanation:** The management of hyperglycemia in pregnancy primarily relies on lifestyle modifications and **Insulin**, which remains the gold standard as it does not cross the placenta. However, among oral hypoglycemic agents (OHAs), **Metformin** is the most widely accepted and safely used option. **1. Why Metformin is Correct:** Metformin (a Biguanide) is category B in pregnancy. While it does cross the placenta, it is not associated with increased rates of major congenital malformations or fetal harm. It is particularly useful in patients with Polycystic Ovary Syndrome (PCOS) to prevent early pregnancy loss and in Gestational Diabetes Mellitus (GDM) when patients are needle-phobic or have compliance issues with insulin. **2. Why Other Options are Incorrect:** * **Sitagliptin (DPP-4 Inhibitor):** There is insufficient human data regarding its safety and efficacy during pregnancy. It is generally avoided. * **Glimepiride (Sulfonylurea):** Most second and third-generation sulfonylureas (except Glyburide/Glibenclamide in specific cases) are avoided due to the risk of prolonged neonatal hypoglycemia and lack of long-term safety data. * **Pioglitazone (Thiazolidinedione):** These are contraindicated as they have shown embryotoxicity in animal studies and can affect fetal bone health. **Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** Insulin is the DOC for both GDM and Pregestational Diabetes. * **Metformin & PCOS:** Continuing Metformin in the first trimester for PCOS patients reduces the risk of miscarriage and development of GDM. * **Glibenclamide:** It is the only other OHA sometimes considered, but it is associated with higher rates of macrosomia and neonatal hypoglycemia compared to Insulin. * **Target Blood Sugars:** Fasting <95 mg/dL, 1-hour postprandial <140 mg/dL, and 2-hour postprandial <120 mg/dL.

Question 83: In testicular feminisation syndrome, which of the following statements are true?

A. Buccal smear is chromatin positive
B. Normal breast size is observed (Correct Answer)
C. Menstruation is scanty and infrequent
D. Familial incidence is recognised

Explanation: **Explanation:** **Testicular Feminization Syndrome (now commonly known as Complete Androgen Insensitivity Syndrome - CAIS)** occurs due to a mutation in the androgen receptor gene. Although the individual has a **46, XY** karyotype and functioning testes, the peripheral tissues are completely unresponsive to androgens. **Why Option B is Correct:** In CAIS, the testes produce high levels of testosterone. Because the receptors are insensitive, this testosterone is peripherally converted (aromatized) into **estrogen**. This estrogen, unopposed by androgens, leads to the development of **normal female breasts** (often with pale areolae). This is a hallmark clinical feature. **Analysis of Incorrect Options:** * **Option A:** The karyotype is 46, XY. Therefore, the buccal smear is **chromatin negative** (no Barr body). * **Option C:** There is a complete absence of the uterus, fallopian tubes, and upper third of the vagina due to the production of **Anti-Müllerian Hormone (AMH)** by the fetal testes. Consequently, there is **primary amenorrhea**, not scanty menstruation. * **Option D:** While CAIS is an X-linked recessive condition and can run in families, the question asks for the "most characteristic" clinical feature among the choices provided. In many standard textbooks, the phenotypic female appearance with normal breast development is the classic diagnostic pointer. **High-Yield Clinical Pearls for NEET-PG:** 1. **Phenotype:** Tall female, absent/scanty axillary and pubic hair (due to androgen insensitivity). 2. **Gonads:** Undescended testes (often found in the inguinal canal or labia majora). 3. **Risk:** Increased risk of **Gonadoblastoma/Dysgerminoma** after puberty; gonadectomy is recommended after the completion of puberty (to allow natural breast development). 4. **Vagina:** Blind-ending pouch (short vagina).

Question 84: Luteal phase defect is best diagnosed by which of the following methods?

A. Serum progesterone levels
B. Endometrial biopsy (Correct Answer)
C. Basal body temperature
D. Ultrasonography

Explanation: **Explanation:** **Luteal Phase Defect (LPD)** is a condition characterized by inadequate progesterone production by the corpus luteum or a failure of the endometrium to respond to progesterone. This results in an endometrium that is out of sync with the menstrual cycle, hindering successful implantation. **Why Endometrial Biopsy is the Correct Answer:** Historically, the **Endometrial Biopsy (EB)** is considered the "Gold Standard" for diagnosing LPD. The procedure is typically performed on day 21–23 of the cycle (or 2–3 days before the expected menses). The diagnosis is confirmed if the histological dating of the endometrium lags behind the actual chronological day of the cycle by **more than 2 days** (Noyes’ criteria). **Analysis of Incorrect Options:** * **A. Serum Progesterone Levels:** While low levels (<10 ng/mL) suggest LPD, progesterone is secreted in a pulsatile manner. A single random sample is often unreliable and may not reflect the total secretory capacity. * **C. Basal Body Temperature (BBT):** BBT shows a biphasic pattern due to the thermogenic effect of progesterone. While a short luteal phase (<10 days) on a BBT chart suggests LPD, it is subjective and lacks the precision of histological dating. * **D. Ultrasonography:** USG can monitor follicular growth and endometrial thickness, but it cannot accurately assess the functional/histological maturity of the endometrium required to diagnose LPD. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** LPD is defined as a luteal phase lasting **<10 days**. * **Noyes’ Criteria:** Used for histological dating of the endometrium. * **Treatment of Choice:** Progesterone supplementation (vaginal or oral) or ovulation induction with Clomiphene Citrate to improve corpus luteum function. * **Current Trend:** In modern clinical practice, EB is less frequently used due to its invasive nature and inter-observer variability, but for exam purposes, it remains the classic diagnostic answer.

Question 85: You are treating a 27-year-old infertile patient with bromocriptine. What is the likely underlying diagnosis?

A. Hyperpituitarism
B. Hypopituitarism
C. Polycystic ovarian disease (PCOD)
D. Hyperprolactinemia (Correct Answer)

Explanation: **Explanation:** **Why Hyperprolactinemia is the Correct Answer:** Bromocriptine is a potent **Dopamine agonist** (specifically at D2 receptors). In the hypothalamic-pituitary axis, dopamine acts as the primary "prolactin-inhibiting factor." By mimicking dopamine, bromocriptine inhibits the secretion of prolactin from the anterior pituitary. In patients with **Hyperprolactinemia**, high prolactin levels suppress the pulsatile release of **GnRH** from the hypothalamus. This leads to decreased FSH and LH levels, resulting in anovulation and infertility. Bromocriptine restores the ovulatory cycle by normalizing prolactin levels, making it the first-line medical treatment for prolactinoma-induced infertility. **Analysis of Incorrect Options:** * **Hyperpituitarism:** This is a broad term referring to the oversecretion of any pituitary hormone (e.g., GH in Acromegaly). While hyperprolactinemia is a type of hyperpituitarism, Bromocriptine is a specific treatment for prolactin excess, not a general treatment for all pituitary hyperfunction. * **Hypopituitarism:** This condition involves a deficiency of pituitary hormones. Treatment requires hormone replacement (e.g., Levothyroxine, Cortisol, or Gonadotropins), not dopamine agonists. * **PCOD:** The primary treatment for infertility in PCOD involves weight loss and ovulation induction with **Letrozole** (first-line) or Clomiphene Citrate. Bromocriptine is only used in PCOD if there is co-existing hyperprolactinemia. **NEET-PG High-Yield Pearls:** * **Drug of Choice:** While Bromocriptine is classic, **Cabergoline** is now preferred due to its higher efficacy, longer half-life (twice-weekly dosing), and better side-effect profile. * **Side Effects:** Bromocriptine often causes nausea, vomiting, and postural hypotension. * **Safety in Pregnancy:** If a patient conceives while on Bromocriptine, the drug is usually discontinued unless the tumor is a macroadenoma. Bromocriptine has the most extensive safety data for use in early pregnancy.

Question 86: In pregnancy, which is the best parameter to be measured in thyroid function tests?

A. TSH (Correct Answer)
B. Free T3
C. T4
D. Total T3

Explanation: **Explanation:** The assessment of thyroid function in pregnancy is complex due to physiological changes. **Serum TSH** is the most sensitive and reliable parameter for screening and diagnosing thyroid disorders in pregnancy. **Why TSH is the correct answer:** During pregnancy, high levels of Estrogen increase **Thyroid Binding Globulin (TBG)** levels. Additionally, hCG (which shares an alpha subunit with TSH) directly stimulates the TSH receptors on the thyroid gland. Despite these fluctuations, the pituitary-thyroid axis remains the most sensitive indicator of thyroid status. TSH levels slightly decrease in the first trimester due to hCG stimulation but remain the gold standard for monitoring because it reflects the actual metabolic status of the patient relative to pregnancy-specific reference ranges. **Why other options are incorrect:** * **Total T4 and Total T3 (Options C & D):** These are unreliable because Estrogen increases TBG, which leads to a physiological rise in *total* hormone levels (approx. 1.5 times the non-pregnant state). Therefore, elevated Total T3/T4 does not necessarily indicate hyperthyroidism. * **Free T3 (Option B):** While Free T4 is often used alongside TSH, Free T3 is rarely used as a primary screening tool unless T3-toxicosis is suspected. Free hormone assays can also be technically challenging due to protein binding changes in pregnancy. **High-Yield Clinical Pearls for NEET-PG:** 1. **Trimester-specific TSH ranges:** If lab-specific ranges aren't available, the traditional targets are: 1st Trimester: **0.1–2.5** mIU/L; 2nd Trimester: **0.2–3.0** mIU/L; 3rd Trimester: **0.3–3.0** mIU/L. 2. **hCG Effect:** Peak hCG levels (at 10–12 weeks) correlate with the lowest TSH levels. 3. **Drug of Choice:** **Propylthiouracil (PTU)** is preferred in the 1st trimester (to avoid Methimazole embryopathy), while **Methimazole** is preferred in the 2nd and 3rd trimesters (to avoid PTU-induced hepatotoxicity).

Question 87: Which of the following is true regarding hCG?

A. Half-life is around 7 days
B. Low levels are seen in hydatidiform mole
C. hCG can be detected as early as 8-9 days after conception (Correct Answer)
D. All of the above

Explanation: **Explanation:** **Human Chorionic Gonadotropin (hCG)** is a glycoprotein hormone secreted by the syncytiotrophoblast of the developing placenta. It plays a crucial role in maintaining the corpus luteum for progesterone production during early pregnancy. **Why Option C is Correct:** hCG enters the maternal circulation at the time of implantation. Implantation typically occurs 6 to 10 days after fertilization (average 8–9 days). Using highly sensitive assays (Immunoradiometric assay - IRMA), hCG can be detected in maternal serum as early as **8–9 days after conception**. In urine, it is usually detectable by the time of the missed period (around 14 days post-conception). **Why Other Options are Incorrect:** * **Option A:** The half-life of hCG is approximately **24 to 36 hours**, not 7 days. This relatively short half-life is clinically significant when monitoring the resolution of trophoblastic disease or ectopic pregnancies. * **Option B:** Hydatidiform mole (molar pregnancy) is characterized by **abnormally high levels** of hCG (often >100,000 mIU/mL) due to the excessive proliferation of trophoblastic tissue. Low levels of hCG are instead associated with ectopic pregnancy or threatened/spontaneous abortion. **High-Yield Clinical Pearls for NEET-PG:** * **Structure:** hCG is a heterodimer. The **$\alpha$-subunit** is identical to LH, FSH, and TSH. The **$\beta$-subunit** is unique and confers biological specificity; hence, pregnancy tests specifically measure the $\beta$-subunit. * **Doubling Time:** In a healthy intrauterine pregnancy, hCG levels double every **48–72 hours** during the first trimester. * **Peak Levels:** hCG levels reach their peak at **8–10 weeks** of gestation (approx. 100,000 mIU/mL) and then decline to a lower plateau for the remainder of the pregnancy. * **Thyroid Link:** Due to its structural similarity to TSH, very high levels of hCG (as seen in molar pregnancy) can cause hyperthyroidism.

Question 88: A pregnant woman at 12 weeks gestation has a fasting blood glucose of 170 mg/dL. What is the antidiabetic drug of choice?

A. Insulin (Correct Answer)
B. Metformin
C. Glipizide
D. Glibenclamide

Explanation: **Explanation:** The patient presents at 12 weeks gestation with a fasting blood glucose of 170 mg/dL. According to DIPSI and FIGO guidelines, a fasting glucose ≥126 mg/dL or a random glucose ≥200 mg/dL at the initial prenatal visit (especially in the first trimester) is diagnostic of **Overt Diabetes (Pre-gestational Diabetes)** rather than Gestational Diabetes Mellitus (GDM). **Why Insulin is the Correct Choice:** Insulin is the **gold standard** and first-line pharmacological treatment for diabetes in pregnancy. It does not cross the placenta, ensuring no direct fetal hypoglycemia or teratogenicity. In cases of overt diabetes or when blood glucose levels are significantly elevated (like 170 mg/dL fasting), oral hypoglycemic agents (OHAs) are often insufficient to achieve the strict glycemic targets required to prevent congenital malformations and macrosomia. **Analysis of Incorrect Options:** * **Metformin (B):** While increasingly used in GDM (after 20 weeks), it crosses the placenta. It is generally not the first choice for overt diabetes diagnosed in the first trimester where rapid, precise control is needed. * **Glipizide (C):** Sulfonylureas are generally avoided in the first trimester due to potential risks of fetal anomalies and prolonged neonatal hypoglycemia. * **Glibenclamide (D):** Though used in some GDM protocols, it is associated with higher rates of macrosomia and neonatal hypoglycemia compared to insulin. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnostic Thresholds:** Fasting >126 mg/dL or HbA1c >6.5% at the first visit = **Overt Diabetes**. * **Target Glucose in Pregnancy:** Fasting <95 mg/dL, 1-hour postprandial <140 mg/dL, and 2-hour postprandial <120 mg/dL. * **Drug of Choice:** Insulin remains the safest and most effective agent for all types of diabetes in pregnancy. * **Fetal Risk:** Overt diabetes in the first trimester significantly increases the risk of **Congenital Malformations** (most common: Cardiac defects; most specific: Caudal Regression Syndrome).

Question 89: True about Braxton Hicks' contractions are all, except?

A. Felt at 4th month
B. Painful (Correct Answer)
C. Contractions last for 1 min
D. Present even when fetus is dead

Explanation: **Explanation:** Braxton Hicks contractions are intermittent, spontaneous, non-rhythmic uterine contractions that occur during pregnancy. The hallmark of these contractions is that they are **painless**. **1. Why "Painful" is the correct answer (the exception):** Braxton Hicks contractions are characterized by a tightening sensation in the abdomen but do not cause cervical dilatation or effacement. Unlike true labor pains, they are **painless**, irregular in frequency, and usually subside with rest or hydration. If contractions become painful and regular, they may indicate preterm or true labor. **2. Analysis of other options:** * **Felt at 4th month:** These contractions start early in pregnancy (around 6 weeks) but are generally not palpable or felt by the mother until the second trimester, typically around the **4th month (16 weeks)**. * **Contractions last for 1 min:** A typical Braxton Hicks contraction lasts approximately **30 to 60 seconds**, though they can occasionally last up to 2 minutes. * **Present even when fetus is dead:** These are intrinsic myometrial activities. Since they are independent of fetal life or movements, they persist even in cases of **Intrauterine Fetal Death (IUFD)**. **Clinical Pearls for NEET-PG:** * **Distinguishing Feature:** Braxton Hicks contractions disappear with walking or sedation, whereas true labor pains intensify. * **Physiological Role:** They are thought to help in the "ripening" of the cervix and maintaining uterine blood flow. * **False Labor:** When Braxton Hicks contractions become frequent and uncomfortable near term, they are often referred to as "False Labor."

Question 90: 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?

A. Infection
B. Hyperemesis gravidarum (Correct Answer)
C. Not taking regular folic acid
D. Pancreatitis

Explanation: **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%).

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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