Prenatal Care Practice Questions

Q: Which of the following biochemical markers is useful in first-trimester screening for Down's syndrome?

PAPP-A. **Explanation:** First-trimester screening for Down syndrome (Trisomy 21) is typically performed between **11 and 13+6 weeks** of gestation. The "Combined Test" includes maternal age, fetal nuchal translucency (NT) via ultrasound, and two biochemical markers: **PAPP-A** (Pregnancy-Associated Plasma Protein-A) and **free β-hCG**. 1. **Why PAPP-A is correct:** In pregnancies affected by Down syndrome, maternal serum levels of **PAPP-A are significantly decreased**, while levels of free β-hCG are increased. PAPP-A is a metalloproteinase produced by the trophoblast; low levels indicate placental dysfunction associated with aneuploidy. **Analysis of Incorrect Options:** * **Inhibin A:** This is a marker used in the **Second-trimester Quadruple Screen** (15–20 weeks). It is elevated in Down syndrome. * **Estradiol:** Specifically, **Unconjugated Estriol (uE3)** is used in the second-trimester Triple or Quadruple screen. It is decreased in Down syndrome. (Note: Estradiol itself is not a standard screening marker). * **Acetylcholinesterase (AChE):** This is a highly specific marker used to confirm **Neural Tube Defects (NTDs)**. It is measured in amniotic fluid following an elevated maternal serum alpha-fetoprotein (MSAFP) result. **High-Yield Clinical Pearls for NEET-PG:** * **The "H-i" Rule:** In Down syndrome, only **H**CG and **I**nhibin-A are **High** (elevated) during second-trimester screening; all other markers (AFP, uE3, PAPP-A) are low. * **Best Time for NT:** 11 weeks to 13 weeks 6 days (CRL 45–84 mm). * **Integrated Screen:** Combines first-trimester (NT + PAPP-A) and second-trimester (Quadruple screen) results for the highest detection rate (~95%).

Q: Chorionic villus sampling is done for all the following indications EXCEPT?

Gastroschisis. **Explanation:** The correct answer is **Gastroschisis**. **1. Why Gastroschisis is the correct answer:** Chorionic Villus Sampling (CVS) is a technique used to obtain fetal tissue for **genetic, metabolic, and DNA analysis**. Gastroschisis is a structural ventral wall defect, not a chromosomal or genetic disorder. Structural anomalies like gastroschisis or neural tube defects (NTDs) are diagnosed via **maternal serum alpha-fetoprotein (MSAFP) screening** and confirmed by **detailed ultrasonography**. CVS cannot detect structural defects because it analyzes the chromosomal makeup, not the physical anatomy or protein markers in the amniotic fluid. **2. Analysis of incorrect options:** * **Options A & B (Down Syndrome / Trisomy 21):** These are chromosomal aneuploidies. CVS allows for a full karyotype or FISH (Fluorescence In Situ Hybridization) to definitively diagnose Trisomy 21. * **Option C (Phenylketonuria):** This is an autosomal recessive metabolic disorder. Since the genetic mutation is present in every cell of the conceptus, DNA analysis of the chorionic villi can identify the specific metabolic mutation. **3. High-Yield Clinical Pearls for NEET-PG:** * **Timing:** CVS is typically performed between **10–13 weeks** of gestation (First Trimester). * **Advantage:** It provides earlier results compared to amniocentesis (15–20 weeks). * **Limitation:** It cannot detect Neural Tube Defects (NTDs). * **Complications:** The most specific risk associated with CVS performed before 9 weeks is **Limb Reduction Defects**. * **Confirmatory Test:** CVS is a diagnostic test, whereas the Combined Test (nuchal translucency + PAPP-A + hCG) is only a screening test.

Q: A 25-year-old lady presents with a pregnancy of 6 weeks. Which of the following is NOT a sign of early pregnancy?

Cullen's sign. **Explanation:** The correct answer is **Cullen’s sign**. This question tests the ability to differentiate between physiological signs of early pregnancy and signs of pathological conditions like ruptured ectopic pregnancy. **1. Why Cullen’s Sign is the Correct Answer:** Cullen’s sign is defined as bluish discoloration or ecchymosis around the umbilicus. It is caused by the tracking of hemoperitoneum (blood in the peritoneal cavity) through the falciform ligament. While it can be seen in a **ruptured ectopic pregnancy**, it is not a physiological sign of a normal early pregnancy. It is also classically associated with acute hemorrhagic pancreatitis. **2. Analysis of Incorrect Options (Physiological Signs):** * **Goodell’s Sign (6–8 weeks):** Softening of the cervix due to increased vascularity and hypertrophy of the cervical glands. * **Hegar’s Sign (6–10 weeks):** Softening of the lower uterine segment (isthmus). On bimanual examination, the upper body of the uterus and the cervix seem like two separate regions because the isthmus is so soft it can be compressed almost paper-thin. * **Palmer’s Sign (4–8 weeks):** Regular, rhythmic, painless uterine contractions felt during a bimanual examination. **High-Yield Clinical Pearls for NEET-PG:** * **Chadwick’s Sign (6–8 weeks):** Bluish discoloration of the cervix, vagina, and labia due to venous congestion (also called Jacquemier’s sign). * **Osiander’s Sign (8 weeks):** Increased pulsations felt in the lateral vaginal fornices due to increased vascularity. * **Piskacek’s Sign:** Asymmetrical enlargement of the uterus if implantation occurs near one of the cornua. * **Ladins Sign (6 weeks):** Softening of the anterior midline of the uterus at the junction with the cervix.

Q: A pregnant woman presents for prenatal care. Her past medical history is significant for a severe illness 3 years ago characterized by fatigue, nausea, anorexia, vomiting, jaundice, joint pains, and generalized skin lesions that slowly disappeared. She has felt well recently. Which lab test should be ordered to investigate the patient's past illness?

Hepatitis B surface antigen (HBsAg). **Explanation:** The patient’s history of jaundice, fatigue, joint pains, and skin lesions (likely Gianotti-Crosti syndrome or urticaria associated with the prodromal phase) strongly suggests a past episode of **Acute Hepatitis B**. In the context of prenatal care, the primary concern is the risk of **Vertical Transmission** (mother-to-child). **1. Why HBsAg is the correct answer:** Hepatitis B surface antigen (HBsAg) is the first serological marker to appear in an infection and the standard screening test in pregnancy. If the patient failed to clear the virus after her illness 3 years ago, she would be a **chronic carrier** (defined by HBsAg persistence for >6 months). Identifying HBsAg-positive status is crucial because it dictates the need for neonatal immunoprophylaxis (HBV vaccine + HBIG) to prevent chronic infection in the newborn. **2. Why the other options are incorrect:** * **IgG CMV antibody:** While CMV is a TORCH infection, the patient’s specific history of jaundice and joint pain is more characteristic of viral hepatitis than CMV. * **IgM antibody to HBsAg:** This is not a standard clinical marker. We measure antibodies *against* the surface antigen (Anti-HBs) to check for immunity, not IgM. * **IgM antibody to HBcAg:** This marker is a sign of **acute** infection or a flare-up. Since her illness occurred 3 years ago and she is currently asymptomatic, this would likely be negative. **Clinical Pearls for NEET-PG:** * **Vertical Transmission Risk:** If a mother is HBsAg positive and **HBeAg positive**, the risk of transmission to the neonate is **90%**. If she is HBeAg negative, the risk drops to about 10-20%. * **Management:** Infants born to HBsAg+ mothers must receive the **HBV vaccine and Hepatitis B Immunoglobulin (HBIG)** within 12 hours of birth. * **Universal Screening:** All pregnant women are screened for HBsAg at the first prenatal visit, regardless of prior testing or vaccination status.

Q: What is the total iron requirement during pregnancy?

1000 mg. **Explanation:** The total iron requirement during a normal singleton pregnancy is approximately **1000 mg**. This requirement is driven by the physiological demands of both the mother and the developing fetus. The distribution of this 1000 mg is as follows: * **Fetus and Placenta:** ~300 mg * **Expansion of Maternal Red Cell Mass:** ~450 mg (to support increased oxygen delivery) * **Obligatory Losses (Skin, Gut, Urine):** ~200 mg * **Blood Loss during Delivery:** ~50 mg (net loss) **Analysis of Options:** * **Option A (1000 mg):** Correct. This represents the cumulative need across all three trimesters. * **Option B (35 mg):** Incorrect. This is roughly the daily iron requirement during the third trimester (approx. 6–7 mg/day), not the total pregnancy requirement. * **Option C (500 mg):** Incorrect. This only covers the maternal red cell expansion but ignores fetal needs and obligatory losses. * **Option D (800 mg):** Incorrect. While some older texts cited 800 mg, modern obstetric guidelines (Williams Obstetrics) standardize the total requirement at 1000 mg. **Clinical Pearls for NEET-PG:** * **Iron Absorption:** Iron absorption increases significantly as pregnancy progresses (minimal in the 1st trimester, peaking in the 3rd). * **Prophylactic Dose:** The Government of India (IFA program) recommends **60 mg elemental iron + 500 mcg folic acid** daily for 180 days starting from the second trimester. * **Therapeutic Dose:** For diagnosed anemia (Hb <11 g/dL), the dose is doubled (120 mg elemental iron daily). * **Net Gain:** Despite the 1000 mg requirement, the "net loss" to the mother is only about 500–600 mg because the iron used for red cell expansion is returned to maternal stores after delivery.

Q: What is the percentage increase seen in plasma volume during pregnancy?

40-50%. **Explanation:** The correct answer is **40-50%**. During pregnancy, the maternal body undergoes significant cardiovascular adaptations to meet the metabolic demands of the fetus and protect the mother against blood loss during delivery. **Why 40-50% is correct:** Plasma volume begins to increase as early as the 6th week of gestation, reaching its peak around **32–34 weeks**. This expansion is driven by the activation of the Renin-Angiotensin-Aldosterone System (RAAS), leading to sodium and water retention. While plasma volume increases by approximately **40–50%** (roughly 1.25 liters), the Red Blood Cell (RBC) mass only increases by about **20–30%**. This disproportionate rise leads to **physiological anemia of pregnancy** due to hemodilution. **Why other options are incorrect:** * **A & B (10-30%):** These values are too low for plasma volume but roughly correspond to the increase in **RBC mass** (20-30%). * **C (30-40%):** While closer, this underestimates the total expansion seen in a singleton pregnancy, which typically reaches the 45-50% mark by the third trimester. **High-Yield Clinical Pearls for NEET-PG:** 1. **Cardiac Output:** Increases by **30–50%**, peaking at 20–24 weeks. 2. **Stroke Volume:** Increases by 25–30%. 3. **Multiple Gestation:** In twin pregnancies, the plasma volume increase is even higher (up to 70%). 4. **Uterine Blood Flow:** Increases from 50 mL/min (pre-pregnancy) to approximately **500–750 mL/min** at term. 5. **Blood Pressure:** Diastolic BP decreases in the first and second trimesters (nadir at 24 weeks) due to decreased systemic vascular resistance (SVR) mediated by progesterone and nitric oxide.

Q: What is a common first-trimester ultrasound finding suggestive of Down syndrome?

Nuchal translucency. **Explanation:** **Nuchal Translucency (NT)** is the correct answer because it is the most sensitive and specific first-trimester ultrasound marker for Down syndrome (Trisomy 21). It refers to the sonographic appearance of a collection of fluid under the skin behind the fetal neck, measured between **11 and 13 weeks 6 days** of gestation. An increased NT (typically >3.0 mm or >95th percentile for crown-rump length) is strongly associated with chromosomal aneuploidies, particularly Trisomy 21, 18, and 13. **Analysis of Incorrect Options:** * **A. Nuchal thickening:** While similar in name, "Nuchal Fold Thickening" is a **second-trimester** marker (measured between 16–20 weeks). A thickness of ≥6 mm is considered abnormal. * **C. Cardiac anomalies:** While common in Down syndrome (e.g., Atrioventricular Septal Defects), these are typically detailed during the second-trimester anomaly scan rather than being the primary screening finding in the first trimester. * **D. Gastrointestinal anomalies:** Conditions like duodenal atresia ("double bubble" sign) are classic for Down syndrome but usually manifest and are diagnosed in the **late second or third trimester**. **High-Yield Clinical Pearls for NEET-PG:** * **Combined Screening:** The most effective first-trimester screen (90% detection rate) combines **NT measurement**, **PAPP-A** (decreased), and **free β-hCG** (increased). * **Nasal Bone:** The absence of the nasal bone on a first-trimester scan is another highly specific marker for Down syndrome. * **Soft Markers:** Other second-trimester markers include echogenic intracardiac focus, echogenic bowel, and short femur/humerus.

Q: A pregnant lady in her first trimester presents with vaginal bleeding. On examination, the os is closed and uterine size corresponds to the period of amenorrhoea. What is the most likely diagnosis?

Threatened abortion. ### Explanation The correct diagnosis is **Threatened Abortion**. This clinical scenario is defined by vaginal bleeding occurring before the 20th week of gestation where the pregnancy continues. **1. Why Threatened Abortion is correct:** The hallmark of threatened abortion is **vaginal bleeding** with a **closed cervical os** and a uterine size that **matches the period of amenorrhea**. The fetus is typically alive, and the process is potentially reversible. **2. Why the other options are incorrect:** * **Septic Abortion:** This involves an abortion (of any type) complicated by pelvic infection. It presents with fever, malodorous vaginal discharge, and uterine tenderness, which are absent here. * **Complete Abortion:** In this case, the entire products of conception have been expelled. While the os is closed, the **uterine size would be smaller** than the period of amenorrhea, and bleeding would have significantly subsided. * **Inevitable Abortion:** The key differentiator here is the cervix. In inevitable abortion, the **cervical os is dilated**, and the patient usually experiences rupture of membranes or more severe pain/bleeding, making the progression to miscarriage certain. **3. NEET-PG High-Yield Pearls:** * **Management:** Treatment for threatened abortion is primarily **bed rest** (though evidence is limited) and **progesterone supplementation** (to support the corpus luteum). * **Ultrasonography:** It is the investigation of choice to confirm fetal viability. * **Prognosis:** Approximately 50% of threatened abortions progress to inevitable abortion. * **Differential Diagnosis:** Always rule out Ectopic Pregnancy (presents with pain and adnexal mass) and Cervical Polyps.

Q: A primigravida with abnormal sonographic findings has decreased alpha fetoprotein (AFP) levels. What condition may the fetus have?

Down's syndrome. **Explanation:** The correct answer is **Down’s Syndrome (Trisomy 21)**. Maternal Serum Alpha-Fetoprotein (MSAFP) is a glycoprotein produced initially by the yolk sac and later by the fetal liver. In pregnancies affected by Down’s syndrome, MSAFP levels are characteristically **decreased** (typically <0.5 MoM). While the exact pathophysiology is not fully understood, it is attributed to reduced synthesis by the fetal liver or a smaller-than-normal yolk sac in the first trimester. **Analysis of Options:** * **Down’s Syndrome (Correct):** Associated with decreased MSAFP, decreased Estriol (uE3), increased hCG, and increased Inhibin-A (the "Quadruple Screen" pattern). * **Anencephaly & Anterior Abdominal Wall Defects (Incorrect):** Conditions like neural tube defects (NTDs) and gastroschisis/omphalocele lead to **increased** MSAFP because the protein leaks directly from the fetal circulation into the amniotic fluid through the exposed defect. * **Renal Anomalies (Incorrect):** Congenital nephrosis (Finnish type) is a classic cause of significantly **elevated** MSAFP due to massive proteinuria into the amniotic fluid. **High-Yield Clinical Pearls for NEET-PG:** * **Causes of Low MSAFP:** Down’s syndrome, Trisomy 18 (Edwards syndrome), Gestational Trophoblastic Disease (GTD), and overestimation of gestational age. * **Causes of High MSAFP:** Open Neural Tube Defects (Anencephaly, Spina Bifida), Abdominal wall defects, Multiple gestations, Renal anomalies, and underestimation of gestational age (most common cause). * **Rule of Thumb:** If the "skin" is not intact (NTDs, Gastroschisis), AFP goes **UP**. If there is a chromosomal trisomy, AFP usually goes **DOWN**.

Question 1

Which of the following biochemical markers is useful in first-trimester screening for Down's syndrome?

Accepted Answer

PAPP-A

Answer

Inhibin

Answer

Estradiol

Answer

Acetylcholinesterase

Question 2

Chorionic villus sampling is done for all the following indications EXCEPT?

Accepted Answer

Gastroschisis

Answer

Down syndrome

Answer

Trisomy 21

Answer

Phenylketonuria

Question 3

A 25-year-old lady presents with a pregnancy of 6 weeks. Which of the following is NOT a sign of early pregnancy?

Accepted Answer

Cullen's sign

Answer

Goodell's sign

Answer

Hegar's sign

Answer

Palmer's sign

Question 4

A pregnant woman presents for prenatal care. Her past medical history is significant for a severe illness 3 years ago characterized by fatigue, nausea, anorexia, vomiting, jaundice, joint pains, and generalized skin lesions that slowly disappeared. She has felt well recently. Which lab test should be ordered to investigate the patient's past illness?

Accepted Answer

Hepatitis B surface antigen (HBsAg)

Answer

IgG cytomegalovirus (CMV) antibody levels

Answer

IgM antibody to HBsAg

Answer

IgM antibody to hepatitis B core antigen

Question 5

What is the total iron requirement during pregnancy?

Accepted Answer

1000 mg

Answer

35 mg

Answer

500 mg

Answer

800 mg

Question 6

What does Chadwick sign indicate?

Accepted Answer

Bluish discoloration or dusky hue of the vestibule and anterior vaginal wall

Answer

Pulsations felt through lateral fornices

Answer

Softening of the cervix

Answer

All of the above

Question 7

What is the percentage increase seen in plasma volume during pregnancy?

Accepted Answer

40-50%

Answer

10-20%

Answer

20-30%

Answer

30-40%

Question 8

What is a common first-trimester ultrasound finding suggestive of Down syndrome?

Accepted Answer

Nuchal translucency

Answer

Nuchal thickening

Answer

Cardiac anomalies

Answer

Gastrointestinal anomalies

Question 9

A pregnant lady in her first trimester presents with vaginal bleeding. On examination, the os is closed and uterine size corresponds to the period of amenorrhoea. What is the most likely diagnosis?

Accepted Answer

Threatened abortion

Answer

Septic abortion

Answer

Complete abortion

Answer

Inevitable abortion

Question 10

A primigravida with abnormal sonographic findings has decreased alpha fetoprotein (AFP) levels. What condition may the fetus have?

Accepted Answer

Down's syndrome

Answer

Anencephaly

Answer

Anterior abdominal wall defects

Answer

Renal anomalies

Prenatal Care — MCQs

Prenatal Care — MCQs

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