Maternal-Fetal Medicine Practice Questions

Q: What is the most common organism causing urinary tract infections in pregnant patients?

E. coli. **Explanation:** **Correct Answer: A. E. coli** *Escherichia coli* is the most common uropathogen in both pregnant and non-pregnant women, accounting for approximately **70–90%** of all urinary tract infections (UTIs). In pregnancy, physiological changes such as progesterone-induced ureteral dilation (hydroureter) and mechanical compression of the bladder by the enlarging uterus lead to urinary stasis. This environment facilitates the ascent of fecal flora, primarily *E. coli*, from the perineum into the urinary tract. **Analysis of Incorrect Options:** * **B. Proteus:** While a known cause of UTIs, it is less common than *E. coli*. It is clinically significant for its association with struvite (staghorn) calculi due to its urease-producing nature. * **C. Staphylococcus saprophyticus:** This is the second most common cause of UTIs in young, sexually active women, but it remains significantly less frequent than *E. coli* in the obstetric population. * **D. Group B hemolytic Streptococcus (GBS):** While GBS can cause UTIs in pregnancy, its primary clinical importance lies in the risk of neonatal sepsis. Any colony count of GBS in a pregnant patient’s urine (even 10⁵ CFU/mL in an asymptomatic patient. It **must** be screened for and treated in pregnancy to prevent progression to pyelonephritis (up to 30-40% risk if untreated). * **Pyelonephritis:** The most common non-obstetric cause of hospitalization in pregnancy; it increases the risk of preterm labor and ARDS. * **Drug of Choice:** Nitrofurantoin or Fosfomycin are common first-line agents for cystitis/ASB. Avoid Nitrofurantoin near term due to the risk of neonatal hemolysis.

Q: Complications of diabetes in pregnancy include all of the following except?

Hyperglycemia in the newborn. **Explanation:** The correct answer is **C. Hyperglycemia in the newborn**. In reality, infants of diabetic mothers (IDMs) are at high risk for **neonatal hypoglycemia**, not hyperglycemia. **Pathophysiology (Pedersen Hypothesis):** Maternal hyperglycemia leads to fetal hyperglycemia because glucose crosses the placenta via facilitated diffusion. However, maternal insulin does not cross the placenta. The fetal pancreas responds to high glucose levels by producing excess insulin (**fetal hyperinsulinemia**). After birth, the glucose supply from the mother is abruptly cut off, but the neonate’s hyperinsulinemic state persists, causing rapid glucose uptake and profound hypoglycemia. **Analysis of Incorrect Options:** * **Macrosomia (A):** Fetal hyperinsulinemia acts as a growth promoter, leading to excessive fat deposition and organomegaly (birth weight >4000g or >4500g). * **Shoulder Dystocia (B):** Macrosomic infants have disproportionate fat deposition around the shoulders and trunk, significantly increasing the risk of birth trauma and shoulder dystocia during vaginal delivery. * **Intrauterine Growth Restriction (D):** While GDM usually causes macrosomia, **Pregestational Diabetes** (Type 1 or 2) with long-standing vascular complications (White’s Class D, F, R) can lead to placental insufficiency, resulting in IUGR. **High-Yield NEET-PG Pearls:** * **Most common cardiac anomaly:** Ventricular Septal Defect (VSD). * **Most specific cardiac anomaly:** Transposition of the Great Arteries (TGA). * **Most specific malformation overall:** Caudal Regression Syndrome (Sacral Agenesis). * **Neonatal Metabolic Triad:** Hypoglycemia, Hypocalcemia, and Hypomagnesemia. * **Other complications:** Polycythemia (due to fetal hypoxia/erythropoietin) and Hyperbilirubinemia.

Q: A 35-week pregnant patient presents with hydramnios and marked respiratory distress. What is the most appropriate management?

Amniocentesis. **Explanation:** The patient presents with **acute/symptomatic polyhydramnios** at 35 weeks gestation. When hydramnios causes maternal compromise—specifically **marked respiratory distress** or severe abdominal pain—the primary goal is to relieve the intra-abdominal pressure to stabilize the mother. **Why Amniocentesis is correct:** **Therapeutic Amniocentesis (Amnioreduction)** is the treatment of choice for symptomatic relief. By slowly removing excess amniotic fluid (usually 500 mL per hour, up to 1.5–2 L), the pressure on the diaphragm is reduced, immediately improving respiratory function. It is preferred over delivery at 35 weeks if the primary issue is mechanical distress, as it allows the pregnancy to gain further maturity while alleviating symptoms. **Why other options are incorrect:** * **A. Intravenous Furosemide:** Hydramnios is an accumulation of fluid in the amniotic sac, not maternal pulmonary edema or systemic fluid overload. Diuretics do not reduce amniotic fluid volume. * **B. Saline Infusion:** This would be used for oligohydramnios (amnioinfusion) or maternal dehydration; it would worsen the volume status in this context. * **D. Artificial Rupture of Membranes (ARM):** Performing ARM in a patient with polyhydramnios and a high presenting part carries a massive risk of **cord prolapse** and **abruptio placentae** due to the sudden decompression of the uterus. **NEET-PG High-Yield Pearls:** * **Definition:** Polyhydramnios is defined as an Amniotic Fluid Index (AFI) > 25 cm or a Single Deepest Pocket (SDP) > 8 cm. * **Indomethacin:** Can be used for medical management (decreases fetal urine output) but is generally avoided after **32 weeks** due to the risk of premature closure of the *ductus arteriosus*. * **Complication Risk:** Always perform amnioreduction slowly to prevent placental abruption.

Q: What is the most common symptom of an ectopic pregnancy?

Pain in the lower abdomen. **Explanation:** The classic clinical triad of ectopic pregnancy consists of **amenorrhea, abdominal pain, and vaginal bleeding**. However, this triad is present in only about 50% of cases. **1. Why "Pain in the lower abdomen" is correct:** Abdominal pain is the **most common presenting symptom**, occurring in approximately **95–99%** of patients. The pain is typically caused by the distension of the fallopian tube or peritoneal irritation from leaking blood. It is usually the first symptom that prompts a patient to seek medical attention. **2. Analysis of Incorrect Options:** * **Amenorrhea (B):** While a history of a missed period is common (75–90%), it is a *sign* or a historical finding rather than the primary *symptom* that defines the clinical presentation. Some patients may mistake early vaginal bleeding for a period, leading to a negative history of amenorrhea. * **Vaginal Bleeding (C):** This occurs in about 60–80% of cases. It is usually "scanty, dark brown (prune juice appearance), and spotting" in nature. While common, it occurs less frequently than abdominal pain. * **Fainting attack (D):** This is a sign of **ruptured ectopic pregnancy** leading to hemoperitoneum and hypovolemic shock. It is a late, life-threatening complication rather than the most common symptom of ectopic pregnancy in general. **NEET-PG High-Yield Pearls:** * **Most common site:** Fallopian tube (97%), specifically the **Ampulla** (most common overall). * **Most common site for rupture:** Isthmus (occurs early, at 6–8 weeks). * **Gold Standard Investigation:** Transvaginal Ultrasound (TVS) combined with quantitative β-hCG (Discriminatory zone: 1500–2000 mIU/mL). * **Arias-Stella Reaction:** Hypersecretory endometrium seen on curettage, suggestive of pregnancy but not specific to ectopic.

Q: In case of unstable lie of fetus, where is the placenta usually located?

Lower segment. **Explanation:** The correct answer is **Lower segment**. **1. Why the Lower Segment is Correct:** An unstable lie refers to a situation where the fetal longitudinal axis frequently changes (e.g., switching between transverse, oblique, and longitudinal) after 37 weeks of gestation. The most common anatomical cause for this is a **Placenta Previa** (placenta located in the lower uterine segment). When the placenta occupies the lower segment, it prevents the fetal head from engaging in the pelvic brim. This lack of engagement allows the fetus excessive mobility, leading to an unstable or transverse lie. **2. Why Other Options are Incorrect:** * **Cornual, Lateral wall, and Fundus:** These are all locations within the **upper uterine segment**. A placenta located in the upper segment is considered normal and does not obstruct the pelvic inlet. In these cases, the fetal head can easily engage, which typically stabilizes the fetus into a longitudinal lie (usually cephalic) as term approaches. **3. Clinical Pearls for NEET-PG:** * **Definition:** Unstable lie is only diagnosed after **37 weeks**; before this, it is common due to relatively high liquor volume. * **Management:** If an unstable lie persists at term, the primary goal is to exclude placenta previa via ultrasound. * **Risk:** The most dangerous complication of an unstable lie with ruptured membranes is **Cord Prolapse**. * **Other Causes:** Apart from placenta previa, consider pelvic tumors (fibroids), polyhydramnios, grand multiparity, and uterine anomalies (e.g., arcuate or subseptate uterus).

Q: Single umbilical artery is associated with which of the following conditions?

Congenital heart disease. **Explanation:** **Single Umbilical Artery (SUA)**, also known as a two-vessel cord, occurs when one of the two umbilical arteries is absent (usually the left). While it is often an isolated finding in 75% of cases, it is a significant marker for associated structural anomalies and chromosomal syndromes (like Trisomy 18). **Why Congenital Heart Disease (CHD) is correct:** Among the various organ systems affected, **cardiovascular anomalies** are the most frequently associated structural defects in fetuses with SUA. Common defects include ventricular septal defects (VSD) and conotruncal abnormalities. Other commonly associated systems include the renal/urinary tract and gastrointestinal systems. **Analysis of Incorrect Options:** * **A. Neural Tube Defects (NTD):** While SUA can be associated with CNS anomalies, NTDs are more specifically linked to folic acid deficiency and are not the primary association for a two-vessel cord. * **B. Hydrops Fetalis:** This is a condition of excessive fluid accumulation in fetal compartments, usually caused by Rh-isoimmunization or parvovirus B19. It is not a classic association of SUA. * **D. In utero fetal demise (IUFD):** While SUA increases the risk of **Intrauterine Growth Restriction (IUGR)** and preterm labor, it is not a direct cause or primary association of fetal demise unless part of a lethal chromosomal syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **Incidence:** Occurs in ~1% of singletons and ~5% of twin pregnancies. * **Most common association:** Cardiovascular and Renal anomalies. * **Management:** If SUA is detected on a level II scan, a **fetal echocardiogram** and detailed renal survey are mandatory. * **Growth:** SUA is strongly associated with **IUGR**; therefore, serial growth scans are recommended in the third trimester even if no structural anomalies are found.

Question 1

What is the recommended first-line medical therapy for hypertension in a pregnant patient with pheochromocytoma?

Accepted Answer

Alpha-blockers

Answer

Calcium-channel blockers

Answer

Beta-blockers

Answer

Hydralazine

Question 2

A 24-year-old woman is pregnant at 14 weeks with her first baby. She feels well and the pregnancy is uncomplicated. Routine screening is positive for chronic viral hepatitis for which perinatal transmission is of major epidemiologic significance. For this patient, what is the most likely viral agent?

Accepted Answer

Hepatitis B virus

Answer

Hepatitis A virus

Answer

Hepatitis C virus

Answer

Hepatitis D virus

Question 3

What is the most common organism causing urinary tract infections in pregnant patients?

Accepted Answer

E. coli

Answer

Proteus

Answer

Staphylococcus saprophyticus

Answer

Group B hemolytic Streptococcus

Question 4

Complications of diabetes in pregnancy include all of the following except?

Accepted Answer

Hyperglycemia in the newborn

Answer

Macrosomia

Answer

Shoulder dystocia

Answer

Intrauterine growth restriction (IUGR)

Question 5

A 35-week pregnant patient presents with hydramnios and marked respiratory distress. What is the most appropriate management?

Accepted Answer

Amniocentesis

Answer

Intravenous furosemide

Answer

Saline infusion

Answer

Artificial rupture of membranes

Question 6

Which one of the following fetal functions is the last to be affected?

Accepted Answer

Tone

Answer

Movement

Answer

Heart rate reactivity

Answer

Breathing movements

Question 7

What is the most common symptom of an ectopic pregnancy?

Accepted Answer

Pain in the lower abdomen

Answer

Amenorrhea

Answer

Vaginal bleeding

Answer

Fainting attack

Question 8

In case of unstable lie of fetus, where is the placenta usually located?

Accepted Answer

Lower segment

Answer

Cornual

Answer

Lateral wall

Answer

Fundus

Question 9

Which hormone does not cross the placenta?

Accepted Answer

None of the above

Answer

Thyroxine

Answer

Estrogen

Answer

Insulin

Question 10

Single umbilical artery is associated with which of the following conditions?

Accepted Answer

Congenital heart disease

Answer

Neural tube defect

Answer

Hydrops fetalis

Answer

In utero fetal demise

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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