Maternal-Fetal Medicine Practice Questions

Q: In diabetic pregnancy, which of the following is least common?

Caudal regression syndrome. In diabetic pregnancies, the risk of congenital malformations is 3–4 times higher than in the general population, primarily due to poor glycemic control during organogenesis. **Explanation of the Correct Answer:** While **Caudal Regression Syndrome** (sacral agenesis) is the **most specific** malformation associated with maternal diabetes (with a relative risk over 200 times higher than the general population), it is actually the **least common** in terms of absolute frequency. In exams, students often confuse "most specific" with "most common." Because the baseline incidence of caudal regression is extremely low, it remains a rare finding compared to other defects. **Analysis of Incorrect Options:** * **Ventricular Septal Defect (VSD):** This is the **most common** congenital malformation seen in infants of diabetic mothers. Cardiovascular anomalies, specifically VSD and Transposition of the Great Arteries (TGA), occur more frequently than any other system defects. * **Anencephaly and Spina Bifida:** Neural Tube Defects (NTDs) are the second most common group of malformations in diabetic pregnancies. The risk of NTDs like anencephaly and spina bifida is increased 10-fold in diabetic mothers compared to the general population. **NEET-PG High-Yield Pearls:** * **Most Specific Malformation:** Caudal Regression Syndrome. * **Most Common Malformation:** Cardiovascular anomalies (specifically VSD). * **Most Common Neonatal Complication:** Hypoglycemia. * **HbA1c Correlation:** The risk of malformations increases significantly if HbA1c is >8.5% during the first trimester. * **Note:** Gestational Diabetes (GDM) usually does not increase the risk of these malformations because hyperglycemia typically develops after the period of organogenesis.

Q: Which of the following is NOT a common cause of placenta accreta?

Previous abruptio placenta. **Explanation:** The core pathophysiology of **Placenta Accreta Spectrum (PAS)** is a defect in the **decidua basalis** (specifically the Nitabuch layer), which allows placental villi to invade the myometrium directly. Any condition that causes scarring or damage to the endometrial-myometrial interface increases this risk. **Why "Previous Abruptio Placenta" is the correct answer:** Abruptio placenta is a clinical event where the placenta prematurely separates from the uterine wall *during* a pregnancy. It is a complication of a current or past pregnancy but does **not** cause permanent structural scarring or thinning of the decidua. Therefore, it is not a recognized risk factor for the abnormal adherence seen in placenta accreta. **Why the other options are incorrect (Risk Factors for Accreta):** * **Previous LSCS (Option A):** This is the **most significant risk factor**. The scar tissue lacks a proper decidual layer. The risk increases exponentially with the number of previous sections (e.g., >60% risk if there is placenta previa and 4+ previous LSCS). * **Previous Curettage (Option B):** Vigorous scraping of the uterine cavity (D&C) can damage the basal endometrium, leading to Asherman syndrome or localized decidual deficiency. * **Previous Myomectomy (Option C):** Any surgery that involves opening the uterine cavity or scarring the myometrium creates a site where the decidua may be absent or defective. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Lower uterine segment (due to poor decidualization). * **Strongest Association:** Previous LSCS + Placenta Previa. * **Nitabuch Layer:** The fibrinoid layer between the decidua basalis and the trophoblast that is **absent** in placenta accreta. * **Management:** The gold standard for confirmed PAS is **Planned Cesarean Hysterectomy**.

Q: What is the typical pH of amniotic fluid in later weeks of gestation?

7.2. **Explanation:** The pH of amniotic fluid is a critical clinical marker used to differentiate it from other vaginal fluids. In the later weeks of gestation, amniotic fluid is **slightly alkaline**, typically ranging between **7.0 and 7.5**, with **7.2** being the most representative value. **Why 7.2 is correct:** Amniotic fluid is primarily composed of fetal urine in the third trimester. Since fetal urine and systemic circulation are slightly alkaline, the resulting fluid maintains a pH above neutral. This alkalinity is the physiological basis for the **Nitrazine test** used to diagnose Premature Rupture of Membranes (PROM). **Analysis of Incorrect Options:** * **A (4.5):** This is the typical **acidic pH of a normal vagina** in a reproductive-age woman (maintained by *Lactobacillus* producing lactic acid). * **B (6.5):** While closer to neutral, this is too acidic for healthy amniotic fluid. However, vaginal secretions mixed with amniotic fluid might show a pH in this range. * **C (7.0):** This is neutral pH. While amniotic fluid can occasionally be 7.0, it is characteristically more alkaline (7.2) in a healthy pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **Nitrazine Test:** When amniotic fluid (pH 7.0–7.5) leaks into the vagina (pH 4.5–5.5), the Nitrazine paper turns **blue** (indicating a pH > 6.0). * **False Positives in Nitrazine Test:** Presence of blood, semen, soap, or antiseptic solutions (like Savlon/Betadine) can cause a false-positive result as they are also alkaline. * **Fern Test:** This is the gold standard for confirming ROM; it relies on the high sodium chloride content of amniotic fluid crystallizing into a "fern" pattern on a slide.

Q: A pseudogestational sac seen on ultrasonography is suspicious of what condition?

Ectopic pregnancy. ### Explanation **Correct Answer: C. Ectopic pregnancy** A **pseudogestational sac** is a common sonographic pitfall in the diagnosis of early pregnancy. It represents an intra-uterine fluid collection (blood or secretions) surrounded by a single layer of decidua, mimicking a true gestational sac. * **Why it indicates Ectopic Pregnancy:** In an ectopic pregnancy, high levels of hCG stimulate the uterine lining, causing a decidual reaction. This can lead to the accumulation of fluid or blood in the endometrial cavity. Unlike a true gestational sac, a pseudogestational sac is **centrally located** (not eccentric), lacks a **yolk sac**, and does not show the **"Double Decidual Sign"** (the two concentric rings representing the decidua capsularis and decidua parietalis). Its presence in a patient with a positive pregnancy test and no visible intrauterine pregnancy should immediately raise suspicion for an ectopic pregnancy. **Analysis of Incorrect Options:** * **A, B, & D (Missed, Incomplete, and Complete Abortion):** These are forms of intrauterine pregnancies (IUP). While they may show an irregular sac or retained products of conception, they are preceded by a true gestational sac. A pseudogestational sac is specifically a "false" sac associated with an extrauterine (ectopic) pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **Double Decidual Sign:** The most reliable sign of a true early IUP (usually seen at 5.5–6 weeks). * **Yolk Sac:** Its presence definitively confirms an IUP and rules out a pseudogestational sac. * **Location:** A true gestational sac is typically **eccentric** (embedded in the endometrium), whereas a pseudogestational sac is **central** (within the uterine cavity). * **Discriminatory Zone:** If the serum β-hCG is >1,500–2,000 mIU/mL and no IUP is seen on TVS, ectopic pregnancy must be excluded.

Q: What is the primary method for the antenatal diagnosis of hydrocephalus?

Ultrasound (USG). **Explanation:** **1. Why Ultrasound (USG) is the Correct Answer:** Ultrasound is the **gold standard and primary modality** for screening and diagnosing fetal structural anomalies, including hydrocephalus. It is non-invasive, cost-effective, and lacks ionizing radiation. The diagnosis is typically made by measuring the **atrial width of the lateral ventricles**. A measurement **>10 mm** at any gestational age is considered ventriculomegaly, which may progress to hydrocephalus. USG can also identify the underlying cause, such as Aqueductal Stenosis or Dandy-Walker malformation. **2. Why the Incorrect Options are Wrong:** * **Alpha-fetoprotein (AFP) estimation:** Elevated AFP levels in maternal serum or amniotic fluid are markers for **Neural Tube Defects (NTDs)** like Anencephaly or Spina Bifida, but they do not directly diagnose hydrocephalus. * **Foetoscopy:** This is an invasive endoscopic procedure used for fetal surgery or direct visualization. It is not a screening or primary diagnostic tool for hydrocephalus due to high procedural risks. * **Amniocentesis:** While used to detect chromosomal abnormalities or infections (which may be associated with hydrocephalus), it cannot visualize the ventricular system to provide a structural diagnosis. **3. High-Yield Clinical Pearls for NEET-PG:** * **Normal Atrial Width:** 15 mm. * **Dangling Choroid Sign:** A classic USG finding in fetal hydrocephalus where the choroid plexus falls dependently within the enlarged lateral ventricle. * **Fetal MRI:** Used as an adjunct to USG for better characterization of posterior fossa anomalies or cortical development issues, but it is not the *primary* method.

Q: A 30-week gestation patient presents with a history of vaginal bleeding and is admitted for evaluation. Fetal heart rate is 130 bpm with normal variability. Ultrasonography reveals a placenta partially covering the internal cervical os. Currently, there is no active vaginal bleeding. What is the best management for this patient?

Resuscitation and observation in a high-risk ward. ### Explanation The patient presents with **Placenta Previa** (partial) at 30 weeks gestation. The management of placenta previa depends on the hemodynamic stability of the mother, the fetal condition, and the gestational age. **Why Option B is Correct:** The primary goal in a preterm patient (30 weeks) who is currently stable with no active bleeding is **expectant management (Macafee and Johnson protocol)**. This approach aims to prolong the pregnancy to achieve fetal maturity while ensuring the patient is in a setting where immediate intervention is possible if bleeding recurs. Observation in a high-risk ward allows for bed rest, monitoring of vitals, and administration of corticosteroids for lung maturity. **Why Other Options are Incorrect:** * **Option A:** Immediate cesarean delivery is indicated only if there is maternal hemodynamic instability, fetal distress, or if the pregnancy has reached 37 weeks. At 30 weeks, delivery should be avoided unless life-threatening bleeding occurs. * **Option C:** Amniocentesis is invasive and unnecessary. Current guidelines favor steroids and expectant management until 36–37 weeks rather than testing for lung maturity. * **Option D:** **Digital vaginal examination is strictly contraindicated** in suspected placenta previa ("No P/V"). It can cause massive, life-threatening hemorrhage by dislodging a clot or piercing the placenta. **NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Transvaginal Ultrasound (TVS) is safer and more accurate than transabdominal ultrasound for locating the placenta. * **Macafee Protocol:** Indicated if gestation is <37 weeks, bleeding is not life-threatening, and the fetus is healthy. * **Steroids:** Administered between 24–34 weeks to reduce the risk of RDS. * **Anti-D:** Must be given to Rh-negative unsensitized mothers following any bleeding episode.

Q: All of the following are used in inherited thrombophilia testing in pregnancy, except:

Lupus anticoagulant. **Explanation:** The core of this question lies in distinguishing between **inherited** and **acquired** thrombophilias. **Why Lupus Anticoagulant is the correct answer:** Lupus anticoagulant (LA) is a component of **Antiphospholipid Antibody Syndrome (APS)**, which is an **acquired** autoimmune thrombophilia. While it is a significant cause of recurrent pregnancy loss and maternal thrombosis, it is not a genetic/inherited condition. Therefore, it does not belong in a panel for *inherited* thrombophilia testing. **Analysis of incorrect options (Inherited Thrombophilias):** * **Antithrombin (AT) deficiency (Option A):** An inherited deficiency. It is the most thrombogenic of all inherited thrombophilias, carrying the highest risk of venous thromboembolism (VTE) during pregnancy. * **Protein C deficiency (Option B):** An inherited autosomal dominant condition. Along with Protein S deficiency, it leads to a failure in neutralizing Factors Va and VIIIa. * **Factor V Leiden mutation (Option C):** The **most common** inherited thrombophilia in Caucasian populations. It involves a point mutation that makes Factor V resistant to inactivation by activated Protein C. **Clinical Pearls for NEET-PG:** * **Most common inherited thrombophilia:** Factor V Leiden mutation. * **Highest risk of VTE in pregnancy:** Antithrombin III deficiency. * **Testing Caution:** Protein S levels naturally decrease during pregnancy; therefore, testing for Protein S deficiency is unreliable during the gestational period and should be done postpartum. * **Screening Indication:** Inherited thrombophilia screening is generally indicated for women with a personal history of VTE or a first-degree relative with high-risk thrombophilia.

Q: Which type of placenta previa is described?

Type 2. ***Type 2*** - **Marginal placenta previa** occurs when the placental edge reaches the **internal cervical os** but does not cover it completely. - This type allows for the possibility of **vaginal delivery** in some cases, unlike complete previa, as the cervical opening remains accessible. *Type 4* - **Complete placenta previa** occurs when the placenta completely covers the **internal cervical os**. - This type always requires **cesarean delivery** as vaginal delivery is impossible due to complete obstruction of the birth canal. *Type 1* - **Low-lying placenta previa** occurs when the placental edge is within **2-3 cm** of the internal os but does not reach it. - This is the mildest form and often allows for **normal vaginal delivery** with close monitoring. *Type 3* - **Partial placenta previa** occurs when the placenta **partially covers** the internal cervical os. - This type typically requires **cesarean delivery** due to significant obstruction of the cervical opening during labor.

Question 1

In diabetic pregnancy, which of the following is least common?

Accepted Answer

Caudal regression syndrome

Answer

Anencephaly

Answer

Ventricular septal defect (VSD)

Answer

Spina bifida

Question 2

Which of the following is NOT a common cause of placenta accreta?

Accepted Answer

Previous abruptio placenta

Answer

Previous lower segment caesarean section (LSCS)

Answer

Previous curettage

Answer

Previous myomectomy

Question 3

What is the typical pH of amniotic fluid in later weeks of gestation?

Accepted Answer

7.2

Answer

4.5

Answer

6.5

Answer

7.0

Question 4

A pseudogestational sac seen on ultrasonography is suspicious of what condition?

Accepted Answer

Ectopic pregnancy

Answer

Missed abortion

Answer

Incomplete abortion

Answer

Complete abortion

Question 5

In a pregnant female with BP 150/100 mm Hg, a protein/creatinine ratio of what value suggests the development of pre-eclampsia?

Accepted Answer

>0.30

Answer

>0.20

Answer

<0.20

Answer

<0.30

Question 6

What is the primary method for the antenatal diagnosis of hydrocephalus?

Accepted Answer

Ultrasound (USG)

Answer

Alpha-fetoprotein (AFP) estimation

Answer

Foetoscopy

Answer

Amniocentesis

Question 7

A 30-week gestation patient presents with a history of vaginal bleeding and is admitted for evaluation. Fetal heart rate is 130 bpm with normal variability. Ultrasonography reveals a placenta partially covering the internal cervical os. Currently, there is no active vaginal bleeding. What is the best management for this patient?

Accepted Answer

Resuscitation and observation in a high-risk ward

Answer

Immediate cesarean delivery

Answer

Amniocentesis to assess fetal lung maturity and plan delivery

Answer

Gentle digital cervical examination to assess dilatation and membrane status

Question 8

All of the following are used in inherited thrombophilia testing in pregnancy, except:

Accepted Answer

Lupus anticoagulant

Answer

Antithrombin deficiency

Answer

Protein C deficiency

Answer

Factor V Leiden mutation

Question 9

Which type of placenta previa is described?

Accepted Answer

Type 2

Answer

Type 4

Answer

Type 1

Answer

Type 3

Question 10

In accidental hemorrhage, what is the definitive treatment?

Accepted Answer

Simultaneous emptying of the uterus and blood transfusion

Answer

Induction of labor

Answer

Treatment of hypofibrinogenemia followed by blood transfusion

Answer

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Maternal-Fetal Medicine — MCQs

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