Which is correct about ABO and Rh incompatibility leading to Erythroblastosis fetalis?
Q2
A USG (ultrasound) shows two babies, one of whom appears to be one month older than the other. What is the term for this condition?
Q3
A 27 -week pregnant woman with a fetus diagnosed with congenital anomalies is considering a Medical Termination of Pregnancy (MTP). Whose presence is not required for the authorization of MTP in this case?
Q4
A 32-year-old female in late pregnancy presents with seizures and high blood pressure. She is diagnosed with eclampsia and started on magnesium sulfate therapy. As part of her management, certain parameters require close monitoring to prevent magnesium toxicity. Which of the following is the MOST important parameter to monitor during magnesium sulfate therapy in this patient?
Q5
A woman at 8 weeks of gestation is diagnosed with hyperthyroidism. Which of the following is the most appropriate treatment option?
High-risk pregnancies US Medical PG Practice Questions and MCQs
Question 1: Which is correct about ABO and Rh incompatibility leading to Erythroblastosis fetalis?
A. Cell mediated hypersensitivity
B. Immune complex
C. Antigen-antibody reaction
D. Cytotoxic (Correct Answer)
Explanation: ***Cytotoxic***
- **Erythroblastosis fetalis** involves maternal antibodies (IgG) crossing the placenta and binding to fetal red blood cell antigens, leading to **complement-mediated lysis** of fetal red blood cells.
- This is a classic example of a **Type II hypersensitivity reaction**, characterized by antibody-mediated cell destruction.
*Cell mediated hypersensitivity*
- This refers to **Type IV hypersensitivity reactions**, which involve T lymphocytes and macrophages, not antibodies.
- Examples include **contact dermatitis** and **tuberculosis skin tests**.
*Immune complex*
- This describes **Type III hypersensitivity reactions**, where antigen-antibody complexes form and deposit in tissues, leading to inflammation.
- Conditions like **serum sickness** and **lupus nephritis** are examples of immune complex diseases.
*Antigen-antibody reaction*
- While present, this option is too broad; all hypersensitivity reactions involve some form of antigen-antibody (or antigen-T cell) interaction.
- It does not specifically describe the **mechanisms of tissue damage** or the **type of hypersensitivity** involved in erythroblastosis fetalis.
Question 2: A USG (ultrasound) shows two babies, one of whom appears to be one month older than the other. What is the term for this condition?
A. Superfetation
B. Superfecundation
C. Twin-to-twin transfusion syndrome (Correct Answer)
D. Dichorionic diamniotic twins
Explanation: ***Twin-to-twin transfusion syndrome***
- The observation of one baby appearing a month older than the other on ultrasound, particularly in a twin pregnancy, is highly suggestive of **twin-to-twin transfusion syndrome (TTTS)**, where there is an unequal sharing of blood between the twins.
- This imbalance leads to one twin (the recipient) becoming larger and plethoric, while the other (the donor) becomes smaller and anemic, creating a noticeable size discrepancy, inaccurately noted as an "older" twin.
*Superfetation*
- **Superfetation** is the rare phenomenon of a second, new pregnancy occurring during an existing pregnancy, resulting in two fetuses of different gestational ages.
- While it results in fetuses of different ages, it specifically refers to conception at different times, which is distinct from the described unequal growth within a single multiple pregnancy.
*Superfecundation*
- **Superfecundation** refers to the fertilization of two or more ova from the same ovulatory cycle by sperm from different acts of coitus or from different fathers.
- It results in twins (or multiples) conceived at roughly the same time, but by different sperm, and does not explain a significant age or size discrepancy between the fetuses.
*Dichorionic diamniotic twins*
- **Dichorionic diamniotic (DCDA) twins** are the most common type of twins, each having their own placenta and amniotic sac.
- While they are two separate pregnancies, this term primarily describes the placental and amniotic sac arrangement and does not inherently explain a significant size discrepancy or "age" difference between the twins without an underlying complication like TTTS.
Question 3: A 27 -week pregnant woman with a fetus diagnosed with congenital anomalies is considering a Medical Termination of Pregnancy (MTP). Whose presence is not required for the authorization of MTP in this case?
A. A. Obstetrician
B. B. Lawyer (Correct Answer)
C. C. Pediatrician
D. D. Sonologist
Explanation: **B. Lawyer**
- The **Medical Termination of Pregnancy Act (MTP Act)** in India specifies the medical professionals required for MTP authorization. A lawyer's presence is not mandated for this medical decision.
- Legal authorization involves medical personnel and, in certain cases, a **Medical Board**, but not legal professionals directly in the authorization process.
*A. Obstetrician*
- An **obstetrician** or gynecologist is a medical expert specializing in pregnancy and childbirth, making their presence crucial for assessing the patient's and fetal condition.
- The **MTP Act** requires the opinion of at least two registered medical practitioners, especially for pregnancies beyond 20 weeks, making an obstetrician essential.
*C. Pediatrician*
- In cases of **fetal anomalies**, a **pediatrician** (or a neonatologist) is highly likely to be part of the Medical Board formed to evaluate the anomaly and assess the prognosis for the child.
- Their expertise helps in understanding the **severity and potential outcomes** of the congenital anomaly, informing the MTP decision.
*D. Sonologist*
- A **sonologist** (radiologist performing ultrasound) is critical for accurately diagnosing and detailing the **congenital anomalies** through imaging.
- Their report provides essential **diagnostic information** that forms the basis for the MTP decision, especially in cases where anomalies are the primary concern.
Question 4: A 32-year-old female in late pregnancy presents with seizures and high blood pressure. She is diagnosed with eclampsia and started on magnesium sulfate therapy. As part of her management, certain parameters require close monitoring to prevent magnesium toxicity. Which of the following is the MOST important parameter to monitor during magnesium sulfate therapy in this patient?
A. Urine output
B. Deep tendon reflexes
C. Serum magnesium levels (Correct Answer)
D. Respiratory rate
Explanation: ***Serum magnesium levels***
- While clinical signs are crucial, direct measurement of **serum magnesium levels** provides the most accurate and objective assessment of magnesium load and toxicity risk.
- Therapeutic ranges are well-defined (4-7 mEq/L or 1.5-3.0 mmol/L), and levels above this indicate increasing toxicity risk, guiding prompt intervention.
*Urine output*
- **Adequate renal function** is essential for magnesium excretion, so decreased urine output can predispose to toxicity.
- However, urine output is an indirect measure and does not precisely reflect the immediate magnesium concentration or neurological effects.
*Deep tendon reflexes*
- **Loss of deep tendon reflexes** (e.g., patellar reflex) is an early and important clinical sign of magnesium toxicity.
- While crucial for clinical assessment, it's a subjective finding that may lag behind dangerously high serum levels.
*Respiratory rate*
- **Respiratory depression** is a severe and life-threatening manifestation of magnesium toxicity, indicating very high serum levels.
- Monitoring respiratory rate is essential, but it's a late sign of toxicity, and waiting for it to decrease means the patient is already significantly over-magnesemic.
Question 5: A woman at 8 weeks of gestation is diagnosed with hyperthyroidism. Which of the following is the most appropriate treatment option?
A. Methimazole
B. Carbimazole
C. Propylthiouracil (Correct Answer)
D. Radioactive iodine
Explanation: ***Propylthiouracil***
- **Propylthiouracil (PTU)** is the preferred treatment for hyperthyroidism in the **first trimester** of pregnancy due to a lower risk of teratogenic effects compared to methimazole.
- While PTU carries a risk of **liver toxicity**, its use is generally favored in early pregnancy to avoid the more severe potential fetal abnormalities associated with other antithyroid drugs during this critical developmental period.
*Methimazole*
- **Methimazole** is associated with a specific pattern of birth defects, including **aplasia cutis congenita** (scalp defects) and **esophageal/choanal atresia**, when used during the first trimester.
- It is generally preferred in the **second and third trimesters** due to a lower risk of maternal hepatotoxicity compared to PTU.
*Carbimazole*
- **Carbimazole** is a **prodrug** that is metabolized to methimazole; therefore, it carries the same teratogenic risks as methimazole in the first trimester.
- Its use during early pregnancy is generally avoided for the same reasons as methimazole.
*Radioactive iodine*
- **Radioactive iodine (RAI)** is **contraindicated** in pregnancy because it crosses the placenta and can cause **fetal hypothyroidism** and irreversible destruction of the fetal thyroid gland.
- It is an effective treatment for hyperthyroidism outside of pregnancy but is never used during gestation.
