Maternal-Fetal Medicine Practice Questions

Q: What is the most common cause of cervical insufficiency?

Idiopathic. **Explanation:** Cervical insufficiency (formerly known as cervical incompetence) is characterized by the inability of the uterine cervix to retain a pregnancy in the second trimester in the absence of clinical contractions. **1. Why Idiopathic is correct:** While there are several known mechanical and congenital risk factors, the **most common cause of cervical insufficiency is idiopathic**. In many patients, no specific history of trauma or structural anomaly is identified. It is often attributed to a functional deficiency in the cervical collagen-to-elastin ratio or biochemical changes in the connective tissue that lead to premature ripening. **2. Analysis of Incorrect Options:** * **Previous Dilatation and Curettage (D&C):** This is a common **acquired** cause. Forceful mechanical dilatation of the internal os can lead to structural damage, but statistically, it occurs less frequently than idiopathic cases. * **Exposure to Diethylstilbestrol (DES):** This is a **congenital** cause. DES exposure in utero leads to structural uterine anomalies (e.g., T-shaped uterus) and cervical hypoplasia. However, DES is now rarely encountered in modern clinical practice. * **Conization:** Cold knife conization or LEEP (Loop Electrosurgical Excision Procedure) removes a significant portion of the cervical stroma, weakening its structural integrity. While a significant risk factor, it is not the most common cause. **NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Clinical history of recurrent painless second-trimester mid-trimester losses. * **USG Finding:** "Funneling" of the internal os and a cervical length **<25 mm** before 24 weeks. * **Treatment:** Cervical Cerclage (McDonald or Shirodkar technique), typically performed between **12–14 weeks** of gestation. * **Emergent Procedure:** "Rescue cerclage" is performed when the cervix is already dilated with bulging membranes.

Q: Pelvic examination is not indicated in which of the following conditions?

Placenta previa. In cases of **Placenta Previa**, the placenta is implanted in the lower uterine segment, covering or near the internal os. Performing a digital pelvic examination (PV) can inadvertently detach the placenta or traumatize the highly vascularized placental bed, leading to **sudden, torrential, and life-threatening hemorrhage**. Therefore, a PV examination is strictly contraindicated unless performed in an "Operation Theatre" under double setup (prepared for immediate Cesarean section). The gold standard for diagnosis is a Transvaginal Ultrasound (TVS), which is safe and accurate. **Explanation of Incorrect Options:** * **Contracted Pelvis:** Pelvic examination (Clinical Pelvimetry) is essential here to assess the pelvic diameters (e.g., diagonal conjugate, ischial spines) and determine the feasibility of vaginal delivery. * **Hydatidiform Mole:** While diagnosis is primarily via USG ("snowstorm appearance") and beta-hCG levels, a PV examination is not contraindicated and may reveal a "doughy" uterus or the presence of theca lutein cysts. * **Ectopic Pregnancy:** A bimanual examination is a standard clinical step to check for cervical motion tenderness (Chandelier sign) and adnexal masses, though it must be performed gently to avoid rupturing the sac. **High-Yield Clinical Pearls for NEET-PG:** * **Warning Hemorrhage:** The first episode of bleeding in placenta previa is usually painless, causeless, and recurrent. * **Rule of Thumb:** In any patient presenting with antepartum hemorrhage (APH), **always** perform a speculum examination to rule out local causes, but **never** perform a digital PV until placenta previa is ruled out by ultrasound. * **Stallworthy’s Sign:** Posterior placenta previa can interfere with the engagement of the fetal head, a classic clinical finding.

Q: Which syndrome is most commonly associated with cystic hygroma in first-trimester ultrasound?

Trisomy 21. **Explanation:** Cystic hygroma is a congenital malformation of the lymphatic system characterized by fluid-filled sacs, most commonly occurring in the neck. Its clinical significance and association with chromosomal anomalies vary significantly depending on the **gestational age** at which it is detected. **1. Why Trisomy 21 is the Correct Answer:** In the **first trimester** (11–14 weeks), the most common chromosomal abnormality associated with cystic hygroma is **Trisomy 21 (Down Syndrome)**. Large-scale screening studies have shown that while cystic hygroma is a non-specific marker of aneuploidy, Trisomy 21 has the highest prevalence among affected fetuses during this early window. **2. Analysis of Incorrect Options:** * **Turner Syndrome (45,X):** This is the most common association in the **second trimester**. While Turner syndrome presents with very large, septated cystic hygromas and hydrops, it is statistically less frequent than Trisomy 21 in first-trimester screenings. * **Trisomy 18 (Edwards) & Trisomy 13 (Patau):** These are frequently associated with increased nuchal translucency and cystic hygroma, but their overall incidence is lower than Trisomy 21. They usually present with other structural anomalies (e.g., choroid plexus cysts, holoprosencephaly, or polydactyly). **High-Yield Clinical Pearls for NEET-PG:** * **First Trimester Association:** Trisomy 21 > Turner Syndrome > Trisomy 18. * **Second Trimester Association:** Turner Syndrome (most common). * **Prognosis:** If the karyotype is normal and the hygroma resolves by 18 weeks, the prognosis is generally good. However, persistent hygroma is associated with a high risk of cardiac defects (most commonly Coarctation of the Aorta in Turner syndrome). * **Management:** Detection of a cystic hygroma in the first trimester warrants immediate counseling for invasive prenatal testing (CVS or Amniocentesis) and a detailed fetal echocardiogram.

Q: In a patient with a prosthetic heart valve, at which gestational age is it generally recommended to switch from warfarin to heparin?

36 weeks. **Explanation:** The management of anticoagulation in pregnant women with prosthetic heart valves is a critical balance between preventing maternal valve thrombosis and minimizing fetal/neonatal risks. **Why 36 weeks is correct:** Warfarin is a highly effective anticoagulant but crosses the placenta. The primary concern near term is the risk of **fetal intracranial hemorrhage** during the mechanical stress of labor and delivery if the fetus is anticoagulated. Therefore, it is standard practice to switch from Warfarin to **Unfractionated Heparin (UFH) or Low Molecular Weight Heparin (LMWH)** at **36 weeks** of gestation. Heparin does not cross the placenta, ensuring the fetus is not anticoagulated during birth. Additionally, UFH has a short half-life and can be easily reversed with Protamine Sulfate if urgent delivery is required. **Analysis of Incorrect Options:** * **A & B (28 and 32 weeks):** Switching this early unnecessarily increases the risk of maternal valve thrombosis. Warfarin is generally superior to heparin for preventing valve thrombosis; thus, it is continued as long as safely possible. * **D (Postpartum):** Waiting until postpartum is dangerous. If the patient goes into labor while on Warfarin, the risk of neonatal hemorrhage is extremely high. Warfarin is typically restarted 6–12 hours after an uncomplicated delivery. **Clinical Pearls for NEET-PG:** * **Warfarin Embryopathy:** Occurs if Warfarin is used between **6–12 weeks** (stippled epiphyses, nasal hypoplasia). * **Preferred Regimen:** Many guidelines suggest Warfarin throughout pregnancy (if dose <5mg) due to lower valve failure rates, but **switching at 36 weeks is mandatory** regardless of the dose. * **Labor Management:** Heparin should be discontinued 4–6 hours (UFH) or 24 hours (LMWH) before planned induction or regional anesthesia.

Q: Placenta previa is characterized by all of the following except?

Presents in first trimester. **Explanation:** Placenta previa is a condition where the placenta is implanted in the lower uterine segment, partially or completely covering the internal os. It is a classic cause of **Antepartum Hemorrhage (APH)**. **Why Option C is the correct answer:** Placenta previa typically presents in the **late second or third trimester** (usually after 28 weeks of gestation). This is because the lower uterine segment begins to form and stretch during this period, causing the placental attachments to shear and bleed. Bleeding in the first trimester is categorized as an abortion, ectopic pregnancy, or molar pregnancy, not placenta previa. **Analysis of other options:** * **Painless bleeding (Option A):** This is the hallmark of placenta previa. Unlike placental abruption, the bleeding occurs without uterine contractions or pain. * **Causeless bleeding (Option B):** The bleeding usually occurs spontaneously without any preceding trauma or obvious inciting factor. * **Recurrent bleeding (Option D):** Bleeding episodes often recur as the lower segment continues to stretch and the cervix begins to efface as term approaches. The first episode (warning hemorrhage) is usually mild. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Transvaginal Ultrasound (TVS) is the gold standard for localization. * **Contraindication:** **Digital vaginal examination** is strictly contraindicated unless the patient is in the operating theater (Double Setup Examination), as it can provoke torrential hemorrhage. * **Stallworthy’s Sign:** A clinical finding where the fetal heart rate slows when the head is pushed into the pelvis, suggesting a posterior placenta previa. * **Risk Factors:** Multiparity, advanced maternal age, and previous Cesarean section (increases risk of Placenta Accreta Spectrum).

Q: Hemoconcentration is seen in which of the following conditions?

Preeclampsia. **Explanation:** In **Preeclampsia**, the fundamental pathophysiology involves widespread endothelial dysfunction. This leads to increased vascular permeability, causing fluid to leak from the intravascular compartment into the interstitial space (resulting in edema). Consequently, there is a **contraction of plasma volume**. While both plasma and red cell mass are affected, the reduction in plasma volume is disproportionately greater, leading to **hemoconcentration** (manifesting as an elevated hematocrit). This is a hallmark of the disease and distinguishes it from the physiological changes of a healthy pregnancy. **Analysis of Incorrect Options:** * **Normal Pregnancy:** This is characterized by **hemodilution**. While both plasma volume and red cell mass increase, the plasma volume increases by ~40–50% while red cell mass increases by only ~20–30%. This disproportion leads to "Physiological Anemia of Pregnancy." * **Ectopic Pregnancy:** If ruptured, this leads to hemorrhage and hypovolemia. Initially, the hematocrit may remain normal, but as compensatory mechanisms shift fluid into the vessels, it results in hemodilution (decreased hematocrit), not hemoconcentration. **High-Yield Clinical Pearls for NEET-PG:** * **Hematocrit Trend:** A rising hematocrit in a hypertensive pregnant woman is an ominous sign indicating worsening disease severity and significant plasma volume depletion. * **The "Gold Standard" Pathophysiology:** Preeclampsia is a disease of "theories," but **endothelial dysfunction** and **vasospasm** are the core mechanisms. * **Fluid Management:** Because patients with preeclampsia are hemoconcentrated but have leaky capillaries, they are at high risk for both pulmonary edema (if over-hydrated) and acute kidney injury (due to low intravascular volume).

Q: Which of the following is NOT a cause of polyhydramnios?

Occult spina bifida. **Explanation:** Polyhydramnios is defined as an Amniotic Fluid Index (AFI) >25 cm or a Single Deepest Pocket (SDP) >8 cm. It occurs due to either overproduction of fetal urine or impaired fetal swallowing. **Why "Occult Spina Bifida" is the correct answer:** In **Open Neural Tube Defects (ONTDs)**, such as *Anencephaly* or *Spina Bifida Cystica*, polyhydramnios occurs because of the transudation of fluid from the exposed meninges and the absence of the swallowing reflex (in anencephaly). However, **Occult Spina Bifida** (Spina Bifida Occulta) is a closed defect where the spinal cord and meninges are covered by skin. Since there is no exposed neural tissue or leakage of cerebrospinal fluid into the amniotic cavity, it does **not** cause polyhydramnios. **Analysis of incorrect options:** * **Diabetes Mellitus:** Maternal hyperglycemia leads to fetal hyperglycemia, causing **osmotic diuresis** and fetal polyuria. * **Swallowing Defects:** Conditions like esophageal atresia, duodenal atresia, or facial clefts prevent the fetus from recycling amniotic fluid, leading to accumulation. * **Multiple Pregnancy:** Specifically in Twin-to-Twin Transfusion Syndrome (TTTS), the recipient twin develops polyuria due to hypervolemia, resulting in polyhydramnios. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of polyhydramnios:** Idiopathic (approx. 50-60%). * **Most common fetal anomaly associated:** Anencephaly. * **Maternal Complications:** Abruptio placentae (due to sudden decompression), Postpartum Hemorrhage (PPH) due to uterine atony, and Cord Prolapse. * **Management:** Therapeutic amniocentesis or Indomethacin (reduces fetal urine output; contraindicated after 32 weeks due to risk of premature closure of Ductus Arteriosus).

Q: What is the investigation of choice in a diabetic mother with a doubtful abnormal fetus?

Sonography. **Explanation:** In a diabetic mother, the primary concern regarding a "doubtful abnormal fetus" is the presence of **congenital malformations**. Diabetes is a known teratogen, increasing the risk of structural defects (most commonly cardiac and neural tube defects). **1. Why Sonography is the Correct Choice:** Sonography (Targeted Imaging for Fetal Anomalies - TIFFA/Level II scan) is the **investigation of choice** because it allows for the direct, non-invasive visualization of fetal anatomy. It is the gold standard for detecting structural anomalies such as sacral agenesis (caudal regression syndrome), ventricular septal defects, and anencephaly, which are more prevalent in diabetic pregnancies. **2. Analysis of Incorrect Options:** * **Glycosylated Hemoglobin (HbA1c):** While high HbA1c levels in the first trimester correlate with an increased risk of malformations, it is a **predictive marker**, not a diagnostic tool for identifying an existing fetal abnormality. * **Amniocentesis & Chorionic Villi Biopsy (CVS):** These are invasive procedures used primarily for **genetic and chromosomal analysis** (karyotyping). Since maternal diabetes typically causes structural/morphological defects rather than chromosomal aneuploidies, these are not the first-line investigations for a "doubtful abnormal fetus" unless a genetic syndrome is specifically suspected. **Clinical Pearls for NEET-PG:** * **Most common anomaly** in infants of diabetic mothers: **Cardiac defects** (specifically VSD). * **Most specific anomaly** for diabetes: **Caudal Regression Syndrome** (Sacral agenesis). * **Best time for anomaly scan:** 18–20 weeks of gestation. * Poor glycemic control (HbA1c >8.5%) significantly increases the risk of congenital malformations.

Question 1

What is the most common cause of cervical insufficiency?

Accepted Answer

Idiopathic

Answer

Previous dilatation and curettage

Answer

Exposure to diethylstilbestrol (DES)

Answer

Conization

Question 2

Pelvic examination is not indicated in which of the following conditions?

Accepted Answer

Placenta previa

Answer

Contracted pelvis

Answer

Hydatidiform mole

Answer

Ectopic pregnancy

Question 3

Which syndrome is most commonly associated with cystic hygroma in first-trimester ultrasound?

Accepted Answer

Trisomy 21

Answer

Trisomy 18

Answer

Trisomy 13

Answer

Turner syndrome

Question 4

A 38-year-old woman, gravida 3, para 2, at 32 weeks' gestation presents with vaginal bleeding. She reports passing two quarter-sized clots of blood this morning. She denies contractions, gushes of fluid, or fetal distress. Her obstetrical history includes two low-transverse cesarean deliveries due to non-reassuring fetal heart rate tracings. An ultrasound reveals a complete placenta previa. For which of the following conditions is this patient at highest risk?

Accepted Answer

Placenta accreta

Answer

Dystocia

Answer

Intrauterine fetal demise (IUFD)

Answer

Preeclampsia

Question 5

In a patient with a prosthetic heart valve, at which gestational age is it generally recommended to switch from warfarin to heparin?

Accepted Answer

36 weeks

Answer

28 weeks

Answer

32 weeks

Answer

Postpartum

Question 6

Placenta previa is characterized by all of the following except?

Accepted Answer

Presents in first trimester

Answer

Painless bleeding

Answer

Causeless bleeding

Answer

Recurrent bleeding

Question 7

Hemoconcentration is seen in which of the following conditions?

Accepted Answer

Preeclampsia

Answer

Normal pregnancy

Answer

Ectopic pregnancy

Answer

All of the above

Question 8

Which of the following is NOT a cause of polyhydramnios?

Accepted Answer

Occult spina bifida

Answer

Diabetes mellitus

Answer

Swallowing defects in fetus

Answer

Multiple pregnancy

Question 9

A G4, P1, L0 female presents for antenatal checkup at 12 weeks of gestation. She has had two prior 1st trimester surgical MTPs and delivered a 7-month-old boy in her last pregnancy who died 14 days after birth due to jaundice. Her blood group is B negative, and she was monitored with repeated blood tests during her last pregnancy. There is no history of anti-D administration. What is true regarding her management?

Accepted Answer

Monitor the pregnancy with Middle Cerebral Artery (MCA) Peak Systolic Velocity (PSV) values

Answer

Perform weekly Indirect Coombs Test (ICT) for anti-D titres

Answer

Administer anti-D injection at 28 weeks if ICT is negative

Answer

Administer anti-D injection irrespective of the ICT result

Question 10

What is the investigation of choice in a diabetic mother with a doubtful abnormal fetus?

Accepted Answer

Sonography

Answer

Glycosylated hemoglobin

Answer

Amniocentesis

Answer

Chorionic villi biopsy

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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