Prenatal Care Practice Questions

Q: A 38-year-old woman, gravida 5, para 4, at 10 weeks gestation presents with a urine culture growing >100,000 CFU/mL of Escherichia coli. She is asymptomatic. What is the best next step in her management?

Amoxicillin-clavulanate. **Explanation:** The patient presents with **Asymptomatic Bacteriuria (ASB)**, defined as the presence of >10^5 CFU/mL of a single uropathogen in a midstream clean-catch urine specimen from an individual without symptoms of a urinary tract infection. **1. Why Amoxicillin-clavulanate is correct:** In pregnancy, ASB must always be treated because physiological changes (ureteral dilation, decreased bladder tone) increase the risk of progression to **acute pyelonephritis** (up to 30-40% if untreated). Pyelonephritis is associated with severe maternal and fetal complications, including preterm labor, low birth weight, and maternal sepsis. **Amoxicillin-clavulanate** is a safe and effective first-line agent in the first trimester. Other common options include Nitrofurantoin (avoid near term) and Fosfomycin. **2. Why the other options are incorrect:** * **Ciprofloxacin:** Fluoroquinolones are generally avoided in pregnancy due to potential risks of fetal **cartilage toxicity** and arthropathy. * **No additional treatment:** This is the standard for non-pregnant patients with ASB. However, in pregnancy, the high risk of progression to pyelonephritis makes screening and treatment mandatory. * **Trimethoprim-sulfamethoxazole:** This is typically avoided in the **first trimester** (due to trimethoprim’s anti-folate effect and risk of neural tube defects) and the **third trimester** (due to sulfonamides' risk of neonatal kernicterus). **Clinical Pearls for NEET-PG:** * **Screening:** All pregnant women should be screened for ASB at **12–16 weeks** (or the first prenatal visit) using a urine culture. * **Follow-up:** A repeat urine culture is mandatory 1–2 weeks after completing treatment to ensure eradication (test of cure). * **Most common organism:** *Escherichia coli* (80% of cases). * **Complication:** Untreated ASB is the most common cause of preventable preterm labor.

Q: Which is the best parameter by ultrasound to assess fetal maturity?

Biparietal diameter at 12 weeks. **Explanation:** The assessment of fetal maturity (gestational age) via ultrasound relies on the principle that biological variability increases as pregnancy progresses. Therefore, measurements taken earlier in pregnancy are significantly more accurate than those taken in the third trimester. **Why Biparietal Diameter (BPD) at 12 weeks is correct:** The **Biparietal Diameter (BPD)** is most accurate when measured between **12 and 20 weeks** of gestation. At 12 weeks, the margin of error is approximately **± 3–5 days**. While Crown-Rump Length (CRL) is the single most accurate parameter overall (when measured between 7–12 weeks), BPD becomes the gold standard once the fetus starts to curl, making CRL difficult to measure accurately. At 12 weeks, BPD provides a highly reproducible and precise estimate of fetal age. **Analysis of Incorrect Options:** * **A. Crown-Rump Length (CRL) at 16 weeks:** CRL is only valid up to **12 weeks**. Beyond this, the fetus undergoes "fetal curling," making linear measurement inaccurate. * **B. Head Circumference (HC) at 36 weeks:** In the third trimester, biological variation and intrauterine crowding significantly reduce accuracy. The margin of error at 36 weeks can be as high as **± 3 weeks**. * **D. Femur Length (FL) at 12 weeks:** While FL is a standard parameter, it is generally used after 14 weeks. At 12 weeks, the BPD is technically easier to visualize and more standardized for dating. **High-Yield Clinical Pearls for NEET-PG:** * **Most accurate overall:** CRL in the 1st trimester (7–12 weeks) with an error of ± 3–5 days. * **Best parameter in 2nd trimester:** BPD (up to 20 weeks). * **Best parameter for Fetal Growth/IUGR:** Abdominal Circumference (AC). * **Best parameter for Weight Estimation:** AC is the most sensitive, but a combination of BPD, HC, AC, and FL is typically used (Hadlock's formula).

Q: A 6-week pregnant lady is diagnosed with sputum positive TB. What is the best management approach?

Start Category I ATT in the first trimester.. **Explanation:** The management of Tuberculosis (TB) in pregnancy is a high-yield topic for NEET-PG. The fundamental principle is that **pregnancy is not a contraindication** to starting Anti-Tubercular Treatment (ATT). **Why Option B is Correct:** According to the National TB Elimination Program (NTEP) and WHO guidelines, a pregnant woman diagnosed with TB should be started on **Category I ATT immediately**, regardless of the trimester. Untreated TB poses a significantly higher risk to both the mother (maternal morbidity) and the fetus (preterm birth, low birth weight, and congenital TB) than the drugs themselves. The standard 6-month regimen (2HRZE + 4HRE) is considered safe in pregnancy. **Why Other Options are Incorrect:** * **Option A:** Delaying treatment until the second trimester allows the disease to progress, increasing the risk of hematogenous spread to the placenta and fetus. * **Option C:** Category II (which included Streptomycin) is no longer the standard of care for new cases. Furthermore, Streptomycin is **contraindicated** in pregnancy as it is ototoxic to the fetus (causes 8th cranial nerve damage). * **Option D:** Category III is an obsolete classification. Treatment should never be delayed until the second trimester for an active sputum-positive case. **Clinical Pearls for NEET-PG:** * **Safe Drugs:** Isoniazid, Rifampicin, Ethambutol, and Pyrazinamide are all safe in pregnancy. * **Pyridoxine (Vitamin B6):** Always co-administer (10–25 mg/day) with Isoniazid in pregnant women to prevent peripheral neuropathy. * **Contraindicated:** Streptomycin (Ototoxicity) and Ethionamide (Teratogenic). * **Breastfeeding:** ATT is not contraindicated during breastfeeding; however, the infant should receive Isoniazid prophylaxis and the BCG vaccine.

Q: A 42-year-old patient, who is 5 weeks pregnant with her fifth baby, is concerned about the risk of Down syndrome due to her advanced maternal age. She has decided to undergo a second-trimester amniocentesis to determine the fetal karyotype. Which of the following is NOT a possible complication of amniocentesis?

Limb reduction defects. **Explanation:** The correct answer is **D. Limb reduction defects**. **1. Why Limb Reduction Defects is the correct answer:** Limb reduction defects are a specific complication associated with **Chorionic Villus Sampling (CVS)**, particularly when performed before 9–10 weeks of gestation. Amniocentesis is typically performed in the second trimester (15–20 weeks), a period after which fetal limb development is complete. Therefore, it does not cause structural limb abnormalities. **2. Analysis of Incorrect Options:** * **A. Amniotic fluid leakage:** This occurs in approximately 1–2% of cases post-procedure. Most cases are managed conservatively with bed rest, and the membranes often seal spontaneously. * **B. Chorioamnionitis:** As an invasive procedure involving a needle entering the sterile amniotic cavity, there is a small but documented risk of introducing infection (less than 1 in 1,000 cases). * **C. Fetal loss rate of less than 0.5%:** Modern ultrasound-guided amniocentesis is very safe. The procedure-related pregnancy loss rate is currently estimated to be between **0.1% and 0.3%** (1 in 300 to 1 in 1,000), which is well below the 0.5% threshold. **3. NEET-PG High-Yield Pearls:** * **Timing:** Mid-trimester amniocentesis is ideally performed at **15–20 weeks**. "Early amniocentesis" (11–13 weeks) is avoided due to higher rates of talipes equinovarus and pregnancy loss. * **CVS vs. Amniocentesis:** CVS can be done earlier (10–13 weeks) but carries a risk of **limb reduction defects** and **confined placental mosaicism**. * **Rh Isoimmunization:** In Rh-negative unsensitized mothers, **Anti-D immunoglobulin** must be administered after amniocentesis to prevent sensitization. * **Gold Standard:** Amniocentesis remains the gold standard for diagnosing fetal chromosomal abnormalities and is the preferred method for detecting neural tube defects (via alpha-fetoprotein levels).

Q: All of the following can be used for establishing antenatal diagnosis except:

Decidua. **Explanation:** The goal of prenatal diagnosis is to obtain genetic or biological material belonging to the **fetus** to identify congenital or genetic abnormalities. **Why Decidua is the Correct Answer (The "Except"):** The **decidua** is the modified mucosal lining of the uterus (endometrium) during pregnancy. Crucially, it is of **maternal origin**, not fetal. Therefore, analyzing decidual tissue would provide the mother’s genetic profile rather than the fetus's, making it useless for establishing an antenatal diagnosis of fetal conditions. **Analysis of Other Options:** * **Fetal Blood:** Obtained via **Cordocentesis** (Percutaneous Umbilical Blood Sampling). It is used for rapid karyotyping, detecting fetal infections, or assessing fetal anemia (e.g., Rh isoimmunization). * **Maternal Blood:** Used in **Non-Invasive Prenatal Testing (NIPT)** to analyze Cell-Free Fetal DNA (cffDNA) that leaks into the mother's circulation. It is also used for maternal serum screening (Triple/Quadruple markers) to assess risks for Down syndrome and neural tube defects. * **Amniotic Fluid:** Obtained via **Amniocentesis** (usually at 15–20 weeks). It contains desquamated fetal cells (amniocytes) used for chromosomal analysis, biochemical tests (AFP), and DNA studies. **NEET-PG High-Yield Pearls:** * **Chorionic Villus Sampling (CVS):** Performed at 10–13 weeks; provides the earliest definitive genetic diagnosis. * **NIPT/cffDNA:** Can be performed as early as 10 weeks; it is a screening test, not a diagnostic one. * **Amniocentesis:** The gold standard for definitive prenatal diagnosis; carries a lower risk of miscarriage (0.5%) compared to CVS (1%). * **Confined Placental Mosaicism:** A potential pitfall in CVS where the placenta and fetus have different genetic makeups.

Q: At which of the following gestational ages does a mother typically first perceive fetal movement?

2 months. **Explanation:** The perception of fetal movement by the mother is clinically termed **Quickening**. The timing of this milestone depends significantly on the mother’s parity: * **Primigravida (First-time mothers):** Typically perceive movement at **18–20 weeks** of gestation. * **Multigravida (Previous pregnancies):** Typically perceive movement earlier, at **16–18 weeks**, due to prior experience and abdominal muscle relaxation. In the context of this question, **4 months** (Option C) is the correct choice. At 16–20 weeks, the pregnancy is in its fourth to fifth lunar month. This is the period when the fetus has developed enough neuromuscular coordination and size for its movements to be felt through the uterine wall. **Analysis of Incorrect Options:** * **Option A (1 month) & B (2 months):** At 4–8 weeks, the embryo/fetus is too small, and movements are purely microscopic or detected only via high-resolution ultrasound. * **Option D (6 months):** By 24 weeks, fetal movements are vigorous and often visible externally. Waiting until 6 months to feel first movement would be a clinical delay (concerning for fetal well-being or incorrect dating). **NEET-PG High-Yield Pearls:** 1. **Quickening** is a subjective sign of pregnancy and is used to cross-check the Expected Date of Delivery (EDD). 2. **Rule of thumb:** Add 22 weeks to the date of quickening in a primigravida and 24 weeks in a multigravida to estimate the EDD. 3. **Ultrasound detection:** Fetal cardiac activity can be seen as early as 6 weeks via Transvaginal Sonography (TVS), long before the mother feels movement.

Q: Maternal serum alpha-fetoprotein screening helps to detect which of the following conditions, except?

Talipes equinovarus. **Explanation:** Maternal Serum Alpha-Fetoprotein (MSAFP) is a glycoprotein produced initially by the yolk sac and later by the fetal liver. It is a crucial screening marker measured between **15–20 weeks** of gestation. **Why Talipes Equinovarus is the correct answer:** Talipes equinovarus (clubfoot) is a structural musculoskeletal deformity involving the bones and tendons of the foot. It does not involve a breach in the fetal skin or an opening into a body cavity; therefore, it does not cause leakage of AFP into the amniotic fluid or maternal circulation. Consequently, MSAFP levels remain normal. **Analysis of Incorrect Options (Conditions with Elevated MSAFP):** Elevated MSAFP occurs when there is a defect in the fetal "barrier," allowing AFP to leak into the amniotic fluid. * **Neural Tube Defects (NTDs):** Conditions like anencephaly and spina bifida (aperta) have exposed neural tissue, leading to significantly high MSAFP. * **Omphalocele & Gastroschisis:** These are ventral abdominal wall defects where the absence of skin coverage over the herniated viscera allows AFP to escape. * **Duodenal Atresia:** This is associated with impaired fetal swallowing of amniotic fluid. Since the fetus cannot clear the AFP normally present in the fluid, levels rise and subsequently increase in maternal serum. **High-Yield Clinical Pearls for NEET-PG:** * **Low MSAFP:** Associated with **Down Syndrome (Trisomy 21)**, Edward Syndrome (Trisomy 18), and Gestational Trophoblastic Disease. * **High MSAFP:** Associated with NTDs, abdominal wall defects, multiple gestations, renal anomalies (Finnish-type nephrosis), and **underestimation of gestational age** (most common cause of unexplained elevation). * **Next Step:** If MSAFP is elevated, the first step is a **Targeted Ultrasound** to rule out dating errors or multiple pregnancies.

Q: A newly married couple, both of whom have achondroplastic dwarfism, presents for preconception counseling. Which of the following advice should NOT be given to the couple?

There is a 50% chance the baby will have normal stature.. **Explanation:** **Achondroplasia** is the most common form of skeletal dysplasia, characterized by a mutation in the **FGFR3 gene**. It follows an **Autosomal Dominant (AD)** inheritance pattern. **1. Why Option C is the correct (incorrect advice) answer:** In this scenario, both parents are heterozygotes (Aa) for achondroplasia. According to Mendelian inheritance (Aa x Aa): * **25% chance (AA):** Homozygous dominant. This is **lethal** in the neonatal period due to severe respiratory insufficiency. * **50% chance (Aa):** Heterozygous. The child will have achondroplasia. * **25% chance (aa):** Homozygous recessive. The child will have **normal stature**. Therefore, the advice that there is a 50% chance of normal stature is mathematically incorrect; the actual chance is only **25%**. **2. Analysis of other options:** * **Option A:** Achondroplasia primarily affects endochondral ossification of long bones. It does **not** affect cognitive development or intelligence. * **Option B:** Women with achondroplasia have a **contracted, platypelloid pelvis**. Due to the significant cephalopelvic disproportion (CPD), a Cesarean section is almost always mandatory. * **Option D:** Achondroplasia is a classic example of an **Autosomal Dominant** condition with 100% penetrance. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** De novo mutations (80%), often associated with **advanced paternal age** (>40 years). * **Radiological sign:** "Trident hand" (persistent space between the 3rd and 4th fingers). * **Homozygous Achondroplasia:** Always lethal; characterized by severe rhizomelic shortening and a small thorax.

Q: A primigravida at full term complains of faintness when lying down. She feels well when she turns to her side or sits up. What is the cause of this faintness?

Inferior Vena Cava (IVC) compression. ### Explanation The clinical scenario describes **Supine Hypotensive Syndrome** (also known as Aortocaval Compression), a common occurrence in late pregnancy. **1. Why the Correct Answer is Right:** In a full-term pregnancy, the gravid uterus is heavy and bulky. When the patient lies in a supine position, the uterus gravitates backward, compressing the **Inferior Vena Cava (IVC)** against the vertebral column. This compression leads to: * **Decreased Venous Return:** Reduced blood flow to the right atrium. * **Decreased Cardiac Output:** Following Frank-Starling’s law, reduced preload leads to reduced stroke volume. * **Hypotension:** This manifests as faintness, dizziness, or nausea. Turning to the **left lateral position** shifts the uterus off the IVC, immediately restoring venous return and relieving symptoms. **2. Why Incorrect Options are Wrong:** * **Option A:** While intra-abdominal pressure increases in pregnancy, it causes symptoms like GERD or breathlessness, not acute postural syncope. * **Option C:** Increased intracranial pressure (ICP) would present with headaches, projectile vomiting, and papilledema, rather than symptoms relieved by changing posture. * **Option D:** Postprandial hypotension occurs due to blood shunting to the GI tract after eating, but it is not specifically triggered by the supine position in a pregnant patient. **3. NEET-PG High-Yield Pearls:** * **Left Lateral Tilt:** Always recommend a 15°–30° left lateral tilt during surgery or labor to prevent fetal distress caused by reduced placental perfusion. * **Aortic Compression:** The uterus also compresses the aorta (Poseiro effect), which may decrease uterine blood flow even if maternal blood pressure remains normal. * **Compensatory Mechanism:** Most women compensate via increased heart rate and collateral circulation (azygos vein), but 5–10% experience significant hypotension.

Question 1

A 38-year-old woman, gravida 5, para 4, at 10 weeks gestation presents with a urine culture growing >100,000 CFU/mL of Escherichia coli. She is asymptomatic. What is the best next step in her management?

Accepted Answer

Amoxicillin-clavulanate

Answer

Ciprofloxacin

Answer

No additional treatment or workup indicated

Answer

Trimethoprim-sulfamethoxazole

Question 2

Which is the best parameter by ultrasound to assess fetal maturity?

Accepted Answer

Biparietal diameter at 12 weeks

Answer

Crown rump length at 16 weeks

Answer

Head circumference at 36 weeks

Answer

Femur length at 12 weeks

Question 3

A 6-week pregnant lady is diagnosed with sputum positive TB. What is the best management approach?

Accepted Answer

Start Category I ATT in the first trimester.

Answer

Wait until the second trimester to start anti-TB treatment (ATT).

Answer

Start Category II ATT in the first trimester.

Answer

Start Category III ATT in the second trimester.

Question 4

A 42-year-old patient, who is 5 weeks pregnant with her fifth baby, is concerned about the risk of Down syndrome due to her advanced maternal age. She has decided to undergo a second-trimester amniocentesis to determine the fetal karyotype. Which of the following is NOT a possible complication of amniocentesis?

Accepted Answer

Limb reduction defects

Answer

Amniotic fluid leakage

Answer

Chorioamnionitis

Answer

A fetal loss rate of less than 0.5%

Question 5

All of the following can be used for establishing antenatal diagnosis except:

Accepted Answer

Decidua

Answer

Fetal blood

Answer

Maternal blood

Answer

Amniotic fluid

Question 6

At which of the following gestational ages does a mother typically first perceive fetal movement?

Accepted Answer

2 months

Answer

1 month

Answer

4 months

Answer

6 months

Question 7

Maternal serum alpha-fetoprotein screening helps to detect which of the following conditions, except?

Accepted Answer

Talipes equinovarus

Answer

Neural tube defects

Answer

Duodenal atresia

Answer

Omphalocele

Question 8

A newly married couple, both of whom have achondroplastic dwarfism, presents for preconception counseling. Which of the following advice should NOT be given to the couple?

Accepted Answer

There is a 50% chance the baby will have normal stature.

Answer

The intelligence of the child will not be affected.

Answer

Delivery will most likely require a Cesarean section.

Answer

The inheritance pattern is autosomal dominant.

Question 9

A primigravida at full term complains of faintness when lying down. She feels well when she turns to her side or sits up. What is the cause of this faintness?

Accepted Answer

Inferior Vena Cava (IVC) compression

Answer

Increased abdominal pressure

Answer

Increased intracranial pressure

Answer

Postprandial hypotension after a heavy meal

Question 10

During a routine return OB visit, an 18-year-old G1P0 patient at 23 weeks gestational age undergoes a urinalysis. The dipstick indicates the presence of trace glucosuria. All other parameters of the urine test are normal. Which of the following is the most likely etiology of the increased sugar detected in the urine?

Accepted Answer

The patient's urinalysis is consistent with normal pregnancy

Answer

The patient has diabetes

Answer

The patient has a urine infection

Answer

The patient's urine sample is contaminated

Prenatal Care — MCQs

Prenatal Care — MCQs

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