Prenatal Care — MCQs

A 31-year-old primigravid woman, known to be HIV positive, is seeking prenatal care. She also has asthma, for which she uses an inhaler. She had a diagnostic laparoscopy at age 20 for pelvic pain and has had no other surgeries. She has no known drug allergies. Counseling regarding vertical transmission of HIV to the fetus is provided. It is recommended that she take antiretroviral therapy during pregnancy to decrease the vertical transmission rate and have a scheduled cesarean delivery. After consideration, the patient chooses not to take antiretrovirals and opts for a vaginal delivery. What is the approximate risk of vertical transmission of HIV (from mother to fetus) for this patient?

Q408Easy

What is the investigation of choice for recurrent abortions in the first trimester?

Q409Medium

A 19-year-old G2P1 woman at 9 weeks' gestation presents for her second prenatal visit. She reports occasional nausea, with no other complaints. Her first child was delivered vaginally without complications. She is not taking any medications and denies ethanol, tobacco, or current drug use. She has a history of intravenous drug abuse but denies using them since the birth of her first child. She has had multiple sexual partners and does not use contraception. On physical examination, her lungs are clear and her heart has a regular rate and rhythm without murmurs, rubs, or gallops. The physician informs her that routine prenatal tests, including an HIV test, will be performed and discusses the risks and benefits. What else should the physician inform the patient before performing the HIV test?

Q410Easy

At how many weeks of gestation is amniocentesis typically performed?

Prenatal Care Indian Medical PG Practice Questions and MCQs

Question 401: A pregnant mother at 10 weeks gestation has previously delivered a baby with an open neural tube defect. Which of the following statements is true?

A. Sodium valproate use is associated with an increased risk of open neural tube defects. (Correct Answer)
B. The risk of recurrence for open neural tube defects is approximately 2-5%.
C. Amniocentesis is the primary method for prenatal diagnosis of neural tube defects.
D. Prophylactic folic acid supplementation should be initiated after conception.

Explanation: ### Explanation **1. Why Option A is Correct:** Sodium Valproate is a known potent teratogen. It interferes with folate metabolism by inhibiting glutamate formyltransferase, leading to a significantly increased risk of **Open Neural Tube Defects (ONTDs)**, specifically spina bifida (approx. 1-2% risk). In a patient with a previous history of ONTD, avoiding such medications is critical. **2. Analysis of Incorrect Options:** * **Option B:** While the recurrence risk for a woman with one previously affected child is often quoted as 2-5%, this option is considered "less correct" in the context of standard MCQ patterns when a definitive pharmacological fact (Option A) is present. Furthermore, some guidelines specify the risk as 3% for a single previous sibling. * **Option C:** The primary screening method for ONTDs is **Maternal Serum Alpha-Fetoprotein (MSAFP)** at 15-20 weeks, followed by a **Targeted Level II Ultrasound** (the gold standard for diagnosis). Amniocentesis (measuring amniotic fluid AFP and Acetylcholinesterase) is now reserved for cases where ultrasound is inconclusive. * **Option D:** For high-risk patients (previous history of ONTD), folic acid must be initiated **pre-conceptionally** (at least 1–3 months before pregnancy) to be effective, as the neural tube closes by the 28th day of gestation. **High-Yield Clinical Pearls for NEET-PG:** * **Dosage:** Standard low-risk dose is **400 mcg/day**. High-risk dose (previous ONTD, DM, or anticonvulsants) is **4 mg/day**. * **Timing:** Neural tube closure occurs between **days 22 and 28** post-conception. * **Screening:** MSAFP is elevated in 80% of cases of open spina bifida and 90% of anencephaly. * **Lemon Sign & Banana Sign:** Classic cranial ultrasound findings associated with spina bifida.

Question 402: Maternal Alpha-fetoprotein levels are increased in which of the following conditions?

A. Neural tube defects (Correct Answer)
B. Diabetes mellitus
C. Fetal cardiac defects
D. Rubella infection

Explanation: **Explanation:** **Alpha-fetoprotein (AFP)** is a glycoprotein synthesized by the fetal yolk sac and later by the fetal liver. It enters the maternal circulation (MSAFP) via diffusion across the placenta and amnion. **Why Neural Tube Defects (NTDs) are correct:** In open neural tube defects (like Anencephaly or Spina bifida cystica), the fetal skin is not intact. This allows AFP to leak directly from the fetal serum and cerebrospinal fluid into the amniotic fluid, leading to significantly elevated levels in both the amniotic fluid and maternal serum. **Analysis of Incorrect Options:** * **Diabetes Mellitus:** Maternal pre-gestational diabetes is actually associated with **decreased** levels of MSAFP. The exact mechanism is unclear but may relate to delayed fetal growth or placental factors. * **Fetal Cardiac Defects:** These do not typically involve a breach in fetal integument or altered protein synthesis; therefore, they do not cause a rise in AFP. * **Rubella Infection:** While intrauterine infections can cause various anomalies, they are not a classic cause of elevated AFP. **High-Yield Clinical Pearls for NEET-PG:** * **Causes of Increased MSAFP:** Open NTDs, Abdominal wall defects (Omphalocele, Gastroschisis), Multiple gestations, Renal anomalies (Congenital nephrosis), and **Underestimation of gestational age** (most common cause of an "abnormal" result). * **Causes of Decreased MSAFP:** Trisomy 21 (Down Syndrome), Trisomy 18 (Edwards Syndrome), Maternal Obesity, and Gestational Trophoblastic Disease. * **Screening Window:** The optimal time for MSAFP screening is **15–20 weeks** of gestation.

Question 403: Mrs. Y, 25 years old, with a previous history of twin pregnancy delivered at 36 weeks, is now at 10 weeks of gestation. What is her obstetric score?

A. G1P1L2
B. G1P2L2
C. G2P1L2 (Correct Answer)
D. G2P2L2

Explanation: To determine the obstetric score, we use the **G-P-L-A** (Gravida, Para, Live, Abortus) system. The key to this question lies in understanding how multiple gestations (twins) affect these parameters. ### **Explanation of the Correct Answer (C: G2P1L2)** 1. **Gravida (G):** Refers to the total number of times a woman has been pregnant, regardless of the outcome. Mrs. Y had one previous twin pregnancy and is currently pregnant again. Thus, **G = 2**. 2. **Para (P):** Refers to the number of pregnancies that have reached the age of viability (usually 20–24 weeks). **Crucially, a multiple gestation (twins/triplets) counts as P1**, not P2, because Para counts the *event* of delivery, not the number of fetuses. Since she delivered at 36 weeks (past viability), **P = 1**. 3. **Live (L):** Refers to the number of living children. Since she delivered twins who are presumably alive, **L = 2**. ### **Why Other Options are Incorrect** * **A (G1P1L2):** Incorrect because it ignores the current pregnancy (she is currently at 10 weeks, making her G2). * **B (G1P2L2):** Incorrect because it ignores the current pregnancy and incorrectly counts twins as P2. * **D (G2P2L2):** Incorrect because it counts the previous twin delivery as two separate parity events. Parity is defined by the number of births, not the number of infants. ### **High-Yield Clinical Pearls for NEET-PG** * **The Twin Rule:** Twins count as **1 Gravida** and **1 Para**, but **2 Live** births. * **Viability:** In India, the age of viability is traditionally considered **28 weeks**, though many international guidelines (and recent Indian updates) use **24 weeks**. Any delivery after this threshold increments the "Para" count. * **Current Pregnancy:** Always remember to include the current pregnancy in the Gravida count, even if it is in the first trimester.

Question 404: All of the following are definitive signs of pregnancy, EXCEPT:

A. Amenorrhoea (Correct Answer)
B. Fetal movements
C. Fetal heart sounds
D. Fetal skeleton seen in X-ray

Explanation: In Obstetrics, signs of pregnancy are categorized into **Presumptive, Probable, and Positive (Definitive)** signs. ### Why Amenorrhoea is the Correct Answer **Amenorrhoea** is a **Presumptive sign**, not a definitive one. While it is often the first sign of pregnancy, it is highly non-specific. It can be caused by various other factors such as Polycystic Ovary Syndrome (PCOS), emotional stress, extreme weight loss, thyroid disorders, or premature ovarian failure. Therefore, it cannot "definitively" confirm a pregnancy. ### Explanation of Incorrect Options (Definitive Signs) Definitive signs are those that can only be attributed to a fetus and nothing else: * **Fetal Heart Sounds (FHS):** Can be detected by Doppler at 10–12 weeks or by Pinard stethoscope at 18–20 weeks. This is a conclusive sign of a live fetus. * **Fetal Movements:** Active movements felt by the *examiner* (not just the mother) are definitive. Palpation of fetal parts also falls into this category. * **Fetal Skeleton on X-ray:** Visualization of the fetal skeleton (usually after 16 weeks) is definitive. However, X-rays are now obsolete in modern obstetrics due to radiation risks and have been replaced by **Ultrasound (USG)**. ### NEET-PG High-Yield Pearls * **Earliest Definitive Sign:** Visualization of the gestational sac by Transvaginal Ultrasound (TVS) at **4.5 to 5 weeks**. * **Quickening:** The first perception of fetal movement by the mother (18 weeks in primigravida, 16 weeks in multigravida). It is a **presumptive** sign because it is subjective. * **Probable Signs:** These include Hegar’s sign, Goodell’s sign, Chadwick’s sign, and positive pregnancy tests (hCG). Note that hCG can be elevated in molar pregnancies or choriocarcinoma, hence it is "probable" rather than "definitive."

Question 405: Chorionic villus sampling is generally performed between which gestational weeks?

A. 8 to 10 weeks
B. 10 to 13 weeks (Correct Answer)
C. 15 to 18 weeks
D. 20 to 24 weeks

Explanation: **Explanation:** **Chorionic Villus Sampling (CVS)** is a prenatal diagnostic procedure used to obtain fetal karyotype by sampling placental tissue (trophoblasts). **1. Why 10 to 13 weeks is correct:** The standard window for CVS is **10 to 13+6 weeks** of gestation. This timing is chosen because the chorion frondosum is sufficiently developed to provide an adequate sample, and it allows for early diagnosis of chromosomal abnormalities (like Down Syndrome) or genetic disorders (like Thalassemia) in the first trimester. **2. Why the other options are incorrect:** * **8 to 10 weeks:** Performing CVS before 10 weeks is contraindicated due to a significantly increased risk of **Limb Reduction Defects** (oromandibular-limb hypogenesis syndrome) and fetal loss. * **15 to 18 weeks:** This is the traditional window for **Amniocentesis**. By this stage, CVS is technically more difficult as the chorion laeve has formed, and amniocentesis becomes the safer, preferred method for obtaining fetal cells. * **20 to 24 weeks:** This period is typically reserved for Cordocentesis (Percutaneous Umbilical Blood Sampling) or detailed fetal anomaly scans. **Clinical Pearls for NEET-PG:** * **Route:** Can be performed Transabdominally (most common) or Transcervically. * **Advantage over Amniocentesis:** Provides results earlier in pregnancy, allowing for safer and more private termination if required. * **Disadvantage:** It cannot detect **Neural Tube Defects (NTDs)** because it does not measure Alpha-fetoprotein (AFP). * **Complication:** Risk of **Confined Placental Mosaicism**, where the placenta shows a different genetic makeup than the fetus, potentially leading to false positives.

Question 406: What is the content of iron in an IFA tablet used for pregnant women?

A. 100 mg (Correct Answer)
B. 200 mg
C. 500 mg
D. 800 mg

Explanation: **Explanation:** The correct answer is **100 mg**. Under the **Anemia Mukt Bharat (AMB)** strategy and the National Iron Plus Initiative (NIPI), the standard prophylactic dose for pregnant women is one Iron and Folic Acid (IFA) tablet daily. Each tablet contains **100 mg of elemental iron** (usually as Ferrous Sulphate) and **500 mcg (0.5 mg) of Folic Acid**. **Why 100 mg is correct:** During pregnancy, the total iron requirement is approximately 1000 mg to support increased red cell mass, fetal growth, and placental development. To prevent iron deficiency anemia, the government mandates 100 mg of elemental iron daily for **180 days**, starting from the second trimester (after the first 12 weeks). **Analysis of Incorrect Options:** * **200 mg:** This is often the total weight of the *ferrous sulfate salt* in a tablet, but it only yields approximately 60–66 mg of *elemental iron*. It is not the standard prophylactic dose. * **500 mg:** This is the dose of **Folic Acid (500 mcg)** in the tablet, not iron. Students often confuse the units (mg vs. mcg). * **800 mg:** This value does not correspond to any standard IFA regimen. **High-Yield Clinical Pearls for NEET-PG:** * **Prophylactic Dose:** 100 mg elemental iron + 500 mcg Folic Acid daily for 180 days. * **Therapeutic Dose:** If hemoglobin is <11 g/dL, the dose is doubled (two tablets daily, i.e., 200 mg elemental iron). * **Timing:** Iron should be taken between meals for better absorption but can be taken after meals if GI side effects occur. Avoid taking it with tea, coffee, or calcium, as they inhibit absorption. * **Postpartum:** The same 100 mg dose is continued for 180 days post-delivery (lactating period).

Question 407: A 31-year-old primigravid woman, known to be HIV positive, is seeking prenatal care. She also has asthma, for which she uses an inhaler. She had a diagnostic laparoscopy at age 20 for pelvic pain and has had no other surgeries. She has no known drug allergies. Counseling regarding vertical transmission of HIV to the fetus is provided. It is recommended that she take antiretroviral therapy during pregnancy to decrease the vertical transmission rate and have a scheduled cesarean delivery. After consideration, the patient chooses not to take antiretrovirals and opts for a vaginal delivery. What is the approximate risk of vertical transmission of HIV (from mother to fetus) for this patient?

A. 2%
B. 8%
C. 25% (Correct Answer)
D. 50%

Explanation: **Explanation:** The risk of vertical transmission of HIV depends significantly on the viral load and the interventions undertaken during pregnancy, labor, and the neonatal period. **Why 25% is correct:** In the absence of any medical intervention—meaning the mother is **not** on Antiretroviral Therapy (ART), does **not** receive intrapartum Zidovudine, and undergoes a **vaginal delivery**—the risk of mother-to-child transmission (MTCT) is approximately **25%** (ranging from 15% to 30%). Transmission can occur in utero (5-10%), during delivery (10-20%), or via breastfeeding (additional 5-20%). Since this patient refused ART and opted for a vaginal delivery, she falls into this high-risk category. **Analysis of Incorrect Options:** * **A (2%):** This is the risk when the viral load is undetectable (<50 copies/mL) due to highly active antiretroviral therapy (HAART) and appropriate obstetric management. * **B (8%):** This represents the reduced risk if only a single intervention is used (e.g., Zidovudine monotherapy or scheduled Cesarean section alone without ART). * **D (50%):** This is an overestimation. Even without treatment, the majority of infants born to HIV-positive mothers do not contract the virus. **NEET-PG High-Yield Pearls:** * **Most common timing:** Most vertical transmission occurs **intrapartum** (during labor and delivery). * **Gold Standard:** The goal is a viral load of **<50 copies/mL**, which reduces transmission to **<1%**. * **Mode of Delivery:** If viral load is **>1000 copies/mL** at 38 weeks, a **Scheduled Cesarean Section** is recommended to reduce transmission. * **Breastfeeding:** In resource-rich settings, breastfeeding is contraindicated. In resource-limited settings (per WHO), exclusive breastfeeding with maternal ART is recommended if safe alternatives are unavailable.

Question 408: What is the investigation of choice for recurrent abortions in the first trimester?

A. Karyotyping (Correct Answer)
B. SLE Ab
C. HIV
D. TORCH infection

Explanation: **Explanation:** **1. Why Karyotyping is the Correct Answer:** Recurrent pregnancy loss (RPL) is defined as two or more consecutive spontaneous abortions. In the **first trimester**, the most common cause of sporadic miscarriage is fetal chromosomal anomalies. However, for *recurrent* losses, parental chromosomal abnormalities (most commonly **balanced reciprocal or Robertsonian translocations**) are found in 3–5% of couples. Therefore, **parental karyotyping** is the investigation of choice to identify genetic causes that predispose a couple to recurrent early losses. **2. Why Other Options are Incorrect:** * **SLE Ab (Antiphospholipid Antibodies):** While Antiphospholipid Syndrome (APLS) is a major treatable cause of RPL, it more characteristically causes mid-trimester losses or late-term complications (preeclampsia, placental insufficiency). Karyotyping remains the primary genetic screen for early-stage recurrence. * **HIV:** Routine screening is part of antenatal care, but HIV is not a recognized cause of recurrent first-trimester abortions. * **TORCH Infection:** This is a common "distractor." Current guidelines (ACOG/RCOG) state that TORCH infections (Toxoplasmosis, Rubella, CMV, Herpes) cause sporadic loss but are **not** causes of recurrent abortion, as the mother develops immunity after the primary infection. **3. Clinical Pearls for NEET-PG:** * **Most common cause of sporadic abortion:** Autosomal trisomy (Trisomy 16 is most common). * **Most common cause of RPL:** Often "unexplained," but among identifiable causes, APLS and parental chromosomal rearrangements are high-yield. * **Uterine causes:** Septate uterus is the most common Mullerian anomaly associated with RPL. * **Luteal Phase Defect:** Historically linked to RPL, but its diagnosis via endometrial biopsy is no longer recommended.

Question 409: A 19-year-old G2P1 woman at 9 weeks' gestation presents for her second prenatal visit. She reports occasional nausea, with no other complaints. Her first child was delivered vaginally without complications. She is not taking any medications and denies ethanol, tobacco, or current drug use. She has a history of intravenous drug abuse but denies using them since the birth of her first child. She has had multiple sexual partners and does not use contraception. On physical examination, her lungs are clear and her heart has a regular rate and rhythm without murmurs, rubs, or gallops. The physician informs her that routine prenatal tests, including an HIV test, will be performed and discusses the risks and benefits. What else should the physician inform the patient before performing the HIV test?

A. Despite the potential for fetal infection, she may opt out of the test. (Correct Answer)
B. Early retroviral therapy will absolutely decrease the chances of transmitting the infection to the baby.
C. The CDC recommends screening only for patients with high-risk factors.
D. The risk of the test includes potential for fetal loss.

Explanation: **Explanation:** The core concept tested here is the **"Opt-out" screening strategy** for HIV in pregnancy. **Why Option A is Correct:** Current clinical guidelines (ACOG and CDC) recommend universal HIV screening for all pregnant women as part of the routine prenatal laboratory panel. However, this is performed using an **"opt-out" approach**, meaning the patient must be informed that the test will be done, but she retains the right to refuse it. Even though vertical transmission is a significant risk, medical ethics and patient autonomy dictate that the patient can opt out of the screening. **Analysis of Incorrect Options:** * **Option B:** While antiretroviral therapy (ART) significantly reduces the risk of vertical transmission (from ~25% to <1%), the word **"absolutely"** is medically inaccurate. No intervention can guarantee 0% transmission. * **Option C:** The CDC recommends **universal screening** for all pregnant women, regardless of risk factors. Relying only on high-risk factors (like her history of IVDU) misses a significant portion of HIV-positive individuals. * **Option D:** HIV screening is a simple maternal blood test (ELISA/Rapid test). It carries **no risk of fetal loss** or physical harm to the pregnancy. **Clinical Pearls for NEET-PG:** * **Universal Screening:** HIV testing should be done in the 1st trimester for all, and repeated in the 3rd trimester (before 36 weeks) for high-risk patients. * **Transmission Risk:** Without treatment, the risk of vertical transmission is ~25%. With ART, viral suppression, and avoidance of breastfeeding, the risk drops to **<1%**. * **Mode of Delivery:** If the maternal viral load is **>1000 copies/mL** near delivery, a planned Cesarean section at 38 weeks is indicated to reduce transmission. * **Post-exposure Prophylaxis:** The neonate should receive Zidovudine (AZT) prophylaxis for 4–6 weeks after birth.

Question 410: At how many weeks of gestation is amniocentesis typically performed?

A. 10-12 weeks
B. 12-20 weeks (Correct Answer)
C. 20-25 weeks
D. 25-30 weeks

Explanation: **Explanation:** **Amniocentesis** is an invasive prenatal diagnostic procedure involving the aspiration of amniotic fluid for genetic analysis (karyotyping, FISH, or PCR). **1. Why 12-20 weeks is correct:** Traditionally, amniocentesis is performed between **15 and 20 weeks** of gestation (mid-trimester). However, for NEET-PG purposes, the window of **12-20 weeks** is the most accurate range provided. Before 15 weeks, it is termed "Early Amniocentesis." The procedure requires a sufficient volume of amniotic fluid (approx. 150-200 mL) and the fusion of the amnion and chorion (which usually occurs by 14-16 weeks) to minimize technical failure and fetal injury. **2. Analysis of Incorrect Options:** * **Option A (10-12 weeks):** This is too early. Performing amniocentesis before 14 weeks is associated with a higher risk of fetal loss, talipes equinovarus (clubfoot), and respiratory distress due to low fluid volume. **Chorionic Villus Sampling (CVS)** is the preferred procedure at 10-13 weeks. * **Options C & D (20-30 weeks):** While "Late Amniocentesis" can be performed after 20 weeks (e.g., for fetal lung maturity or managing Rh isoimmunization), it is not the "typical" timing for diagnostic genetic screening, which aims for earlier results to allow for legal termination of pregnancy if abnormalities are found. **Clinical Pearls for NEET-PG:** * **Most common complication:** Fetal loss (approx. 0.1% to 0.5%). * **Indication:** Advanced maternal age (>35 years), abnormal triple/quadruple screen, or previous child with chromosomal anomalies. * **Rh-Negative Mothers:** Must receive **Anti-D immunoglobulin** after the procedure to prevent isoimmunization. * **Gold Standard:** Amniocentesis is the gold standard for diagnosing chromosomal abnormalities, though NIPT (Non-Invasive Prenatal Testing) is now a preferred screening tool.

Practice by Chapter

Preconception Counseling

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Pregnancy Diagnosis and Dating

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Routine Antenatal Assessments

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Maternal Physiological Changes

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Nutrition in Pregnancy

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Screening Tests in Pregnancy

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Fetal Growth Assessment

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High-Risk Pregnancy Identification

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Antenatal Complications Management

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Psychosocial Aspects of Pregnancy

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