Endocrinology of Pregnancy Practice Questions

Q: What is the primary cause of mild breathlessness experienced during normal pregnancy?

Progesterone-induced stimulation of the respiratory centre. ***Progesterone-induced stimulation of the respiratory centre*** - Pregnancy leads to a significant increase in **progesterone** levels, which directly stimulates the **medullary respiratory center**. - This increase in **minute ventilation** leads to a drop in arterial PCO2 (respiratory alkalosis), which is subjectively perceived by the pregnant patient as **dyspnea** or breathlessness. *Decreased tidal volume* - This is incorrect as **tidal volume** actually increases significantly (by about 40%) during pregnancy to meet increased oxygen demands. - A decreased tidal volume would lead to hypoventilation, which is the opposite of the hyperventilation observed in normal pregnancy. *Reduced oxygen intake* - Oxygen consumption increases during pregnancy due to the needs of the **fetus**, the **placenta**, and maternal tissues, not a reduction in intake. - Pregnant women compensate for these increased metabolic demands by increasing **minute ventilation**, ensuring adequate oxygen delivery. *Increased arterial PCO2 levels* - Arterial PCO2 levels actually decrease in pregnancy (typically to 27-32 mmHg) due to increased **alveolar ventilation**. - An increase in arterial PCO2 would signify respiratory acidosis or hypoventilation, which contradicts the normal physiological adaptations of pregnancy.

Q: Which of the following findings is diagnostic of Gestational Diabetes Mellitus (GDM) based on the 75g Oral Glucose Tolerance Test (OGTT) as per NICE 2015 criteria?

Fasting blood glucose ≥ 5.6 mmol/L. **Explanation:** The diagnosis of Gestational Diabetes Mellitus (GDM) varies globally based on the criteria used (NICE, IADPSG/WHO, or DIPSI). According to the **NICE (National Institute for Health and Care Excellence) 2015 guidelines**, GDM is diagnosed if a woman has either: 1. **Fasting plasma glucose (FPG) ≥ 5.6 mmol/L** (100 mg/dL) 2. **2-hour plasma glucose ≥ 7.8 mmol/L** (140 mg/dL) **Analysis of Options:** * **Option C (Correct):** A fasting value of **≥ 5.6 mmol/L** is the specific threshold defined by NICE. This reflects an inability of the maternal pancreas to maintain euglycemia during the fasting state despite the physiological insulin resistance of pregnancy. * **Option A:** 5.1 mmol/L is the fasting threshold used by **IADPSG and WHO (2013)** criteria, not NICE. * **Option B:** 7.0 mmol/L is the threshold for diagnosing **Pre-gestational (Type 2) Diabetes** in the general population or during the first trimester. * **Option D:** 5.8 mmol/L is significantly lower than any diagnostic threshold for a 2-hour OGTT; the NICE threshold is 7.8 mmol/L. **High-Yield NEET-PG Pearls:** * **DIPSI Criteria (Common in India):** Uses a non-fasting 75g OGTT. A 2-hour value **≥ 140 mg/dL (7.8 mmol/L)** is diagnostic, regardless of the last meal. * **IADPSG/WHO Criteria:** Fasting ≥ 5.1 mmol/L, 1-hr ≥ 10.0 mmol/L, or 2-hr ≥ 8.5 mmol/L (Only one abnormal value is needed). * **Screening Time:** Usually performed between **24–28 weeks** of gestation when insulin resistance (mediated by Human Placental Lactogen) peaks.

Q: What is the commonest complication of diabetes complicating pregnancy?

Ventricular septal defect (VSD). **Explanation:** In pregnancies complicated by pre-gestational diabetes (Type 1 or Type 2), the risk of congenital malformations is 3–4 times higher than in the general population, primarily due to the teratogenic effects of maternal hyperglycemia during organogenesis. **1. Why Ventricular Septal Defect (VSD) is correct:** While there are many anomalies associated with diabetes, **Congenital Heart Diseases (CHD)** are the most frequent group of malformations. Among these, **Ventricular Septal Defect (VSD)** is statistically the **most common** specific cardiac anomaly encountered. It is important to distinguish between "most common" and "most specific." **2. Analysis of Incorrect Options:** * **B. Atrial septal defect (ASD):** While ASDs occur in diabetic pregnancies, they are less frequent than VSDs. * **C. Sacral agenesis (Caudal Regression Syndrome):** This is the **most specific** (pathognomonic) malformation associated with maternal diabetes. Although highly characteristic, it is rare. NEET-PG often tests the distinction between "most common" (VSD) and "most specific" (Sacral Agenesis). * **D. Anencephaly:** Neural tube defects (NTDs) are the second most common group of anomalies after cardiac defects, but they occur less frequently than VSDs. **Clinical Pearls for NEET-PG:** * **Most Common System Involved:** Cardiovascular system. * **Most Common Specific Anomaly:** VSD. * **Most Specific/Pathognomonic Anomaly:** Sacral agenesis (Caudal regression). * **HbA1c Correlation:** The risk of malformations increases significantly if the periconceptional HbA1c is >8.5%. * **Gestational Diabetes (GDM):** Unlike pre-gestational diabetes, GDM (developing after 24 weeks) is **not** associated with an increased risk of congenital anomalies because organogenesis is already complete.

Q: A 30-year-old married female diagnosed with prolactinoma, showing a 5 mm microadenoma on pituitary MRI, is currently taking bromocriptine. Her urine pregnancy test has turned positive. What is the best advice for her?

Stop bromocriptine. ***Stop bromocriptine*** - For a **microadenoma** (<10 mm), the standard protocol is to discontinue **dopamine agonists** as soon as pregnancy is confirmed to minimize fetal drug exposure. - The risk of clinically significant tumor enlargement during pregnancy for patients with a **microprolactinoma** is exceptionally low, typically **less than 2%**. *Start cabergoline* - **Cabergoline** is not indicated for initiation during pregnancy; the goal is to stop medical therapy rather than switch or start new medications. - While cabergoline is potent for tumor shrinkage, **bromocriptine** has a longer established safety record for use in women attempting to conceive. *Advise trans-sphenoidal surgery anticipating increase in tumor size during pregnancy* - Surgery is not indicated for a **5 mm microadenoma** as the risk of symptomatic growth or visual field defects is negligible. - **Trans-sphenoidal surgery** is reserved for cases where medical therapy fails or for **macroadenomas** causing progressive neurological symptoms. *Advise abortion considering the teratogenic potential of bromocriptine* - **Bromocriptine** is not considered **teratogenic**, and extensive clinical data shows no increase in congenital malformations or miscarriages. - Pregnancy is safely managed in patients with prolactinomas through **clinical monitoring** rather than termination.

Q: At which day of gestation is the maximum level of beta-hCG observed?

9 weeks. **Explanation:** Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone secreted by the syncytiotrophoblast. It is essential for maintaining the corpus luteum, which produces progesterone to support the pregnancy until the placenta takes over (luteal-placental shift). **Why 9 weeks is correct:** The levels of beta-hCG rise exponentially following implantation. In a normal pregnancy, the concentration doubles approximately every 48 hours. The **peak levels (maximum concentration)** are typically reached between **8 to 11 weeks** of gestation (mean peak at 60–70 days or roughly 9 weeks), reaching values of up to 100,000 mIU/mL. After this peak, levels decline to a lower, stable plateau for the remainder of the pregnancy. **Why other options are incorrect:** * **6 weeks:** At this stage, hCG levels are still in the rapid rising phase and have not yet reached their maximum concentration. * **28 weeks & 36 weeks:** By the third trimester, hCG levels have already declined to a steady state (nadir), which is approximately 10–20% of the peak value. **High-Yield Clinical Pearls for NEET-PG:** * **Detection:** hCG can be detected in maternal serum 8–9 days after fertilization and in urine by 14 days. * **Structure:** It shares a common **alpha subunit** with TSH, LH, and FSH. The **beta subunit** is unique and specific for pregnancy testing. * **Clinical Significance of Abnormal Levels:** * **Higher than expected:** Multiple pregnancy, Molar pregnancy (Hydatidiform mole), or Down syndrome. * **Lower than expected:** Ectopic pregnancy or impending miscarriage. * **Nadir:** The lowest level after the peak is reached at approximately 16–20 weeks.

Q: Late hyperglycemia in pregnancy is associated with which of the following conditions?

Macrosomia. **Explanation:** The timing of hyperglycemia in pregnancy significantly dictates the fetal outcome. This question focuses on **Late Hyperglycemia** (occurring in the 2nd and 3rd trimesters), which is the hallmark of Gestational Diabetes Mellitus (GDM). **1. Why Macrosomia is Correct:** The underlying mechanism is the **Pedersen Hypothesis**. Maternal hyperglycemia leads to fetal hyperglycemia because glucose crosses the placenta via facilitated diffusion (GLUT-1). However, maternal insulin does not cross the placenta. The fetal pancreas responds by secreting excess insulin (fetal hyperinsulinemia). Since insulin is a potent **anabolic hormone** and a growth promoter (similar to IGF-1), it causes excessive deposition of fat and glycogen in fetal tissues, leading to **Macrosomia** (birth weight >4kg). **2. Analysis of Incorrect Options:** * **Congenital Malformations:** These occur due to **Early Hyperglycemia** (pre-gestational diabetes) during the period of organogenesis (first 8 weeks). High glucose levels are teratogenic. * **Intrauterine Growth Restriction (IUGR):** This is typically seen in long-standing pre-gestational diabetics with **vasculopathy** (White’s Classification Class R/F), leading to placental insufficiency. Late hyperglycemia in GDM usually causes overgrowth, not restriction. * **Postmaturity:** Diabetes is more commonly associated with preterm birth or elective induction; it does not physiologically cause post-term pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **Most common malformation** in diabetic pregnancy: Congenital Heart Disease (specifically VSD). * **Most specific malformation:** Caudal Regression Syndrome (Sacral Agenesis). * **Neonatal complications:** Hypoglycemia (due to persistent hyperinsulinemia), Hypocalcemia, Hyperbilirubinemia, and Polycythemia. * **Best screening test for GDM:** DIPSI criteria (75g glucose load regardless of last meal; 2-hour value ≥140 mg/dL).

Question 1

What is the primary cause of mild breathlessness experienced during normal pregnancy?

Accepted Answer

Progesterone-induced stimulation of the respiratory centre

Answer

Decreased tidal volume

Answer

Reduced oxygen intake

Answer

Increased arterial PCO2 levels

Question 2

Which of the following statements regarding Turner syndrome is false?

Accepted Answer

The occurrence of Turner syndrome is influenced by advanced maternal age.

Answer

Most patients present with primary amenorrhea.

Answer

Most patients exhibit short stature.

Answer

Edema of the hands and feet is a significant feature during infancy.

Question 3

What is the best approach to prevent congenital anomalies in infants of diabetic mothers?

Accepted Answer

Maintain periconceptional tight control of maternal blood glucose levels

Answer

Discontinue insulin and begin glyburide

Answer

Switch from an oral hypoglycemic agent to insulin until 36 weeks of gestation

Answer

Provide continuous insulin infusion during labor and delivery

Question 4

Which of the following findings is diagnostic of Gestational Diabetes Mellitus (GDM) based on the 75g Oral Glucose Tolerance Test (OGTT) as per NICE 2015 criteria?

Accepted Answer

Fasting blood glucose ≥ 5.6 mmol/L

Answer

Fasting blood glucose > 5.1 mmol/L

Answer

Fasting blood glucose > 7.0 mmol/L

Answer

2-hour post-prandial OGTT > 5.8 mmol/L

Question 5

What is the commonest complication of diabetes complicating pregnancy?

Accepted Answer

Ventricular septal defect (VSD)

Answer

Atrial septal defect (ASD)

Answer

Sacral agenesis

Answer

Anencephaly

Question 6

A 30-year-old married female diagnosed with prolactinoma, showing a 5 mm microadenoma on pituitary MRI, is currently taking bromocriptine. Her urine pregnancy test has turned positive. What is the best advice for her?

Accepted Answer

Stop bromocriptine

Answer

Start cabergoline

Answer

Advise trans-sphenoidal surgery anticipating increase in tumor size during pregnancy

Answer

Advise abortion considering the teratogenic potential of bromocriptine

Question 7

Which of the following statements about prolactinoma in pregnancy is FALSE?

Accepted Answer

Increased prolactin levels during pregnancy indicate a worse prognosis.

Answer

Prolactinoma is the most common pituitary tumor but is rarely symptomatic during pregnancy.

Answer

Macroadenomas greater than 1 cm are associated with a poorer prognosis.

Answer

Regular visual checkups are recommended for patients with prolactinoma during pregnancy.

Question 8

At which day of gestation is the maximum level of beta-hCG observed?

Accepted Answer

9 weeks

Answer

6 weeks

Answer

28 weeks

Answer

36 weeks

Question 9

What is an increased risk in pregnant women with thyroid peroxidase antibodies?

Accepted Answer

Abruptio placenta

Answer

Pre-term delivery

Answer

Preterm rupture of membranes

Answer

Placenta previa

Question 10

Late hyperglycemia in pregnancy is associated with which of the following conditions?

Accepted Answer

Macrosomia

Answer

Intrauterine growth restriction (IUGR)

Answer

Postmaturity

Answer

Congenital malformation

Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy — MCQs

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