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.

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

Endocrinology of Pregnancy — MCQs

Endocrinology of Pregnancy — MCQs

On this page

Practice by Chapter

Want unlimited practice?