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ABOG Maternal-Fetal Medicine study materials
ABOG Maternal-Fetal Medicine study resources

ABOG Maternal-Fetal Medicine practice questions

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Question 1Maternal Medical Complications of Pregnancy

A 28-year-old G2P1 at 26 weeks has a fasting plasma glucose of 96 mg/dL and a 1-hour 50-g glucose challenge test of 152 mg/dL. Which test is the appropriate next step to diagnose gestational diabetes?

  1. 100-g 3-hour oral glucose tolerance test Correct answer.
  2. Hemoglobin A1c
  3. Repeat 50-g glucose challenge test
  4. Random plasma glucose

Explanation

A 1-hour 50-g screen of 130-140 mg/dL or higher (threshold varies by practice) requires diagnostic confirmation with the 100-g 3-hour OGTT using Carpenter-Coustan or NDDG criteria. Hemoglobin A1c is not sensitive enough for GDM diagnosis, and a random glucose does not establish the diagnosis.

Question 2Maternal Medical Complications of Pregnancy

Which medication is first-line for chronic hypertension in pregnancy when pharmacologic therapy is indicated?

  1. Losartan
  2. Labetalol Correct answer.
  3. Lisinopril
  4. Atenolol

Explanation

Labetalol, nifedipine, and methyldopa are the preferred agents for chronic hypertension in pregnancy. ACE inhibitors and angiotensin receptor blockers are contraindicated because of fetal renal and teratogenic effects.

Question 3Maternal Medical Complications of Pregnancy

A woman with mechanical mitral valve prosthesis requires anticoagulation throughout pregnancy. Which regimen carries the lowest maternal risk of valve thrombosis?

  1. Low-molecular-weight heparin throughout pregnancy
  2. Low-dose aspirin alone
  3. Continued warfarin with dose adjustment Correct answer.
  4. Unfractionated heparin throughout pregnancy

Explanation

Continued warfarin provides the most effective protection against maternal thromboembolism for mechanical valves, though it carries fetal warfarin embryopathy risk, especially in the first trimester. LMWH and UFH are less effective and require anti-Xa or aPTT monitoring.

Question 4Maternal Medical Complications of Pregnancy

A pregnant woman at 30 weeks presents with a blood pressure of 148/96 mmHg and 3+ proteinuria. Which laboratory finding would be most consistent with HELLP syndrome?

  1. Platelet count 88,000/µL with elevated AST and LDH Correct answer.
  2. Platelet count 250,000/µL with normal AST
  3. Prolonged PT with normal platelet count
  4. Isolated elevations of alkaline phosphatase

Explanation

HELLP syndrome is characterized by hemolysis (elevated LDH and schistocytes), elevated liver enzymes, and low platelets (typically <100,000/µL). The combination of thrombocytopenia and transaminitis is the diagnostic hallmark.

Question 5Maternal Medical Complications of Pregnancy

Which finding most strongly suggests that a seizure in a woman at 36 weeks with hypertension is eclampsia rather than epilepsy?

  1. Seizure preceded by an aura and incontinence
  2. History of prior seizures since adolescence
  3. Blood pressure 168/110 mmHg with hyperreflexia Correct answer.
  4. Normal platelet count and liver enzymes

Explanation

Eclampsia should be suspected when a seizure occurs in the setting of new-onset hypertension with proteinuria or end-organ dysfunction. Severe hypertension with hyperreflexia supports eclampsia, whereas a long-standing seizure history suggests epilepsy.

Question 6Maternal Medical Complications of Pregnancy

A woman with type 1 diabetes is planning pregnancy. Which intervention most reduces the risk of congenital malformations?

  1. Tight glycemic control before conception targeting A1c <6.5% Correct answer.
  2. Starting folic acid at 12 weeks gestation
  3. Strict control beginning at 8 weeks gestation
  4. Switching to an insulin pump in the first trimester

Explanation

Congenital malformations in pregestational diabetes correlate with periconceptional hyperglycemia, so achieving near-normal glycemia before conception is the most effective preventive measure. Organogenesis occurs in the first 8 weeks, so control starting later misses the critical window.

Question 7Maternal Medical Complications of Pregnancy

A pregnant woman at 34 weeks has a platelet count of 90,000/µL, mildly elevated LDH, and schistocytes on smear without hypertension or proteinuria. Which diagnosis is most likely?

  1. HELLP syndrome
  2. Thrombotic thrombocytopenic purpura Correct answer.
  3. Immune thrombocytopenic purpura
  4. Gestational thrombocytopenia

Explanation

Microangiopathic hemolytic anemia with schistocytes and thrombocytopenia in the absence of hypertension suggests TTP, which requires urgent plasma exchange. Gestational thrombocytopenia is mild and not hemolytic, and HELLP is typically associated with preeclampsia.

Question 8Maternal Medical Complications of Pregnancy

Which maternal cardiac lesion carries the highest risk of maternal mortality in pregnancy?

  1. Pulmonary arterial hypertension Correct answer.
  2. Atrial septal defect
  3. Mitral stenosis
  4. Bicuspid aortic valve

Explanation

Pulmonary arterial hypertension carries a high maternal mortality risk (roughly 25-50%) because the fixed pulmonary vascular resistance cannot accommodate the increased cardiac output of pregnancy. Mitral stenosis and left-to-right shunts carry lower but still significant risk.

Question 9Maternal Medical Complications of Pregnancy

A woman at 24 weeks with systemic lupus erythematosus has positive anti-Ro/SSA antibodies. Which fetal surveillance is indicated?

  1. Maternal serum alpha-fetoprotein screening
  2. Routine amniocentesis for karyotype
  3. Weekly biophysical profiles from 24 weeks
  4. Serial fetal echocardiography to detect congenital heart block Correct answer.

Explanation

Maternal anti-Ro/SSA and anti-La/SSB antibodies cross the placenta and can cause immune-mediated fetal atrioventricular block, so serial fetal echocardiography is recommended, typically from 16 to 26 weeks.

Question 10Maternal Medical Complications of Pregnancy

Which is the most common cause of maternal mortality related to pregnancy in the United States?

  1. Sepsis
  2. Hypertensive disorders
  3. Cardiovascular disease Correct answer.
  4. Hemorrhage

Explanation

Cardiovascular disease is the leading cause of pregnancy-related death in the United States, followed by other medical conditions, infection, hemorrhage, and hypertensive disorders.

Question 11Maternal Medical Complications of Pregnancy

A pregnant woman with a history of venous thromboembolism is being counseled about anticoagulation. Which statement about low-molecular-weight heparin is correct?

  1. It crosses the placenta and can cause fetal anticoagulation
  2. It does not cross the placenta and is safe in pregnancy Correct answer.
  3. It requires monitoring with the INR
  4. It is contraindicated in all trimesters

Explanation

LMWH does not cross the placenta because of its large molecular size and is the preferred anticoagulant in pregnancy. Its effect is monitored with anti-Xa levels rather than INR.

Question 12Maternal Medical Complications of Pregnancy

A woman at 32 weeks with preeclampsia develops a blood pressure of 168/112 mmHg. What is the most appropriate immediate management?

  1. Intravenous labetalol or hydralazine with continuous fetal monitoring Correct answer.
  2. Oral methyldopa and repeat blood pressure in 4 hours
  3. Magnesium sulfate alone without antihypertensive therapy
  4. Oral labetalol and discharge home

Explanation

Severe hypertension (≥160/110 mmHg) in preeclampsia is a medical emergency requiring prompt intravenous antihypertensive therapy to prevent stroke, along with maternal and fetal monitoring. Magnesium sulfate prevents seizures but does not treat the hypertension itself.

Question 13Maternal Medical Complications of Pregnancy

A pregnant woman with asthma experiences worsening symptoms in the second trimester. Which statement about asthma management in pregnancy is correct?

  1. Theophylline is the preferred controller agent
  2. Inhaled corticosteroids should be discontinued to avoid fetal risk
  3. Oral corticosteroids are absolutely contraindicated
  4. Asthma exacerbations are more dangerous to the fetus than controller medications Correct answer.

Explanation

Uncontrolled asthma causes maternal hypoxemia and fetal growth restriction, so maintaining control with inhaled corticosteroids is safer than withholding therapy. Most inhaled agents are considered safe in pregnancy.

Question 14Maternal Medical Complications of Pregnancy

A woman at 28 weeks with a history of bariatric surgery presents with persistent vomiting and abdominal pain. Which diagnosis should be considered?

  1. Gestational diabetes
  2. Hyperemesis gravidarum
  3. Preeclampsia with hepatic involvement
  4. Internal hernia with bowel obstruction Correct answer.

Explanation

Roux-en-Y gastric bypass creates mesenteric defects that can lead to internal herniation, a surgical emergency that may present with abdominal pain and vomiting. Pregnancy increases intra-abdominal pressure and may precipitate this complication.

Question 15Maternal Medical Complications of Pregnancy

Which is the recommended treatment for a pregnant woman with acute pyelonephritis?

  1. Oral nitrofurantoin as an outpatient
  2. Observation with repeat urine culture in one week
  3. Single-dose intramuscular ceftriaxone followed by discharge
  4. Intravenous antibiotics with hospitalization and monitoring Correct answer.

Explanation

Acute pyelonephritis in pregnancy requires hospitalization for intravenous antibiotics and monitoring for sepsis and preterm labor. Outpatient oral therapy is inadequate for upper urinary tract infection in pregnancy.

Question 16Maternal Medical Complications of Pregnancy

A pregnant woman at 20 weeks is diagnosed with Graves disease. Which medication is preferred for treatment during pregnancy?

  1. Propylthiouracil Correct answer.
  2. Levothyroxine
  3. Methimazole
  4. Radioactive iodine

Explanation

Propylthiouracil is preferred in the first trimester because methimazole is associated with aplasia cutis and embryopathy. PTU carries a small risk of hepatotoxicity, so some clinicians switch to methimazole later in pregnancy.

Question 17Maternal Medical Complications of Pregnancy

A pregnant woman with a mechanical heart valve on warfarin is at 10 weeks gestation. Which complication is most associated with warfarin exposure at this gestational age?

  1. Renal agenesis
  2. Cleft palate
  3. Nasal hypoplasia and stippled epiphyses Correct answer.
  4. Neural tube defects

Explanation

Warfarin embryopathy, occurring with first-trimester exposure, includes nasal hypoplasia and stippled epiphyses (chondrodysplasia punctata). Later exposure is associated with CNS abnormalities.

Question 18Maternal Medical Complications of Pregnancy

A woman at 33 weeks with severe preeclampsia has a platelet count of 95,000/µL, AST of 120 U/L, and creatinine of 1.3 mg/dL. Which management is most appropriate?

  1. Expectant management until 37 weeks
  2. Delivery after maternal stabilization with magnesium sulfate Correct answer.
  3. Amniocentesis for fetal lung maturity before delivery
  4. Outpatient blood pressure monitoring

Explanation

Severe features of preeclampsia at ≥34 weeks, or at any gestational age with maternal or fetal compromise, warrant delivery after stabilization. Magnesium sulfate is given for seizure prophylaxis.

Question 19Maternal Medical Complications of Pregnancy

Which laboratory abnormality is most characteristic of acute fatty liver of pregnancy?

  1. Hyperglycemia with metabolic alkalosis
  2. Isolated thrombocytosis
  3. Isolated hyperbilirubinemia with normal coagulation
  4. Hypoglycemia with coagulopathy and elevated ammonia Correct answer.

Explanation

Acute fatty liver of pregnancy causes microvesicular hepatic steatosis with impaired gluconeogenesis and synthetic function, leading to hypoglycemia, coagulopathy, and elevated ammonia. It is a medical emergency requiring delivery.

Question 20Maternal Medical Complications of Pregnancy

A pregnant woman with epilepsy is being counseled about antiepileptic drugs. Which agent is associated with the highest risk of neural tube defects?

  1. Valproic acid Correct answer.
  2. Lamotrigine
  3. Levetiracetam
  4. Carbamazepine

Explanation

Valproic acid carries the highest risk of major congenital malformations, particularly neural tube defects, and is avoided when possible in pregnancy. Levetiracetam and lamotrigine have more favorable profiles.

Question 21Maternal Medical Complications of Pregnancy

A woman with sickle cell disease is at 28 weeks gestation. Which complication should be most closely monitored for?

  1. Hyperthyroidism
  2. Polyhydramnios
  3. Painful vaso-occlusive crisis and acute chest syndrome Correct answer.
  4. Gestational diabetes

Explanation

Pregnancy increases the risk of vaso-occlusive crises and acute chest syndrome in sickle cell disease, along with preeclampsia and fetal growth restriction. Close hematologic monitoring and hydration are essential.

Question 22Maternal Medical Complications of Pregnancy

A pregnant woman at 30 weeks with a history of renal transplant has a creatinine of 1.8 mg/dL. Which statement about pregnancy after renal transplantation is most accurate?

  1. Stable graft function with creatinine <1.5 mg/dL is associated with the best outcomes Correct answer.
  2. Pregnancy is contraindicated in all transplant recipients
  3. Calcineurin inhibitors must be discontinued
  4. Rejection risk is unchanged from nonpregnant patients

Explanation

The best pregnancy outcomes occur in transplant recipients with stable graft function, typically creatinine <1.5 mg/dL, no recent rejection, and controlled blood pressure. Immunosuppression is continued with dose monitoring.

Question 23Maternal Medical Complications of Pregnancy

Which maternal condition is most strongly associated with fetal congenital complete heart block?

  1. Maternal hyperthyroidism
  2. Maternal anti-Ro/SSA antibodies Correct answer.
  3. Maternal phenylketonuria
  4. Maternal diabetes

Explanation

Anti-Ro/SSA and anti-La/SSB antibodies can cross the placenta and cause immune-mediated damage to the fetal atrioventricular node, resulting in congenital heart block.

Question 24Maternal Medical Complications of Pregnancy

A woman with phenylketonuria is planning pregnancy. What is the primary intervention to prevent fetal complications?

  1. Maintain a phenylalanine-restricted diet with phenylalanine levels of 120-360 µmol/L before conception Correct answer.
  2. Avoid all dietary protein throughout pregnancy
  3. Supplement with tyrosine only after delivery
  4. Start a low-protein diet in the second trimester

Explanation

Maternal PKU causes microcephaly, intellectual disability, and congenital heart defects when maternal phenylalanine is elevated. Strict dietary control with phenylalanine levels of 120-360 µmol/L should be achieved before conception and maintained throughout pregnancy.

Question 25Maternal Medical Complications of Pregnancy

A pregnant woman at 26 weeks presents with palpitations and is found to have new-onset atrial fibrillation with rapid ventricular response. Which management is most appropriate?

  1. Observation without treatment
  2. Rate control with a beta-blocker and evaluation for underlying causes Correct answer.
  3. Immediate electrical cardioversion without evaluation
  4. Digoxin as first-line rate control

Explanation

New-onset atrial fibrillation in pregnancy warrants rate control (typically with a beta-blocker) and evaluation for precipitating causes such as thyroid disease, electrolyte abnormalities, or structural heart disease.

Question 26Maternal Medical Complications of Pregnancy

A 29-year-old woman with a body mass index of 34 kg/m² is undergoing screening for gestational diabetes at 24 weeks. Which risk factor in her history most strongly increases the likelihood of gestational diabetes mellitus?

  1. Chronic hypertension
  2. First-degree relative with type 2 diabetes Correct answer.
  3. Group B streptococcus colonization
  4. Prior spontaneous preterm birth

Explanation

Gestational diabetes risk is driven largely by factors reflecting underlying insulin resistance, and a first-degree relative with diabetes is among the strongest established historical risk factors. Obesity, advanced maternal age, prior gestational diabetes, and prior macrosomia similarly raise risk.

Question 27Maternal Medical Complications of Pregnancy

A 31-year-old woman at 12 weeks gestation has a known seizure disorder and reports two generalized tonic-clonic seizures in the past month despite adherence to levetiracetam. Which factor most commonly explains increased seizure frequency during pregnancy?

  1. Progressive structural degeneration of the epileptic focus
  2. Suppression of hepatic cytochrome enzymes by placental hormones
  3. Development of de novo autoimmune encephalitis
  4. Falling serum concentrations of antiseizure medication due to altered pharmacokinetics Correct answer.

Explanation

Pregnancy increases plasma volume, renal clearance, and hepatic metabolism of many antiseizure drugs, so serum levels of agents such as levetiracetam and lamotrigine often fall and breakthrough seizures occur. Monitoring drug levels and adjusting doses accordingly is the standard response.

Question 28Maternal Medical Complications of Pregnancy

A 26-year-old woman at 22 weeks with a history of bariatric surgery is diagnosed with iron deficiency anemia that has not responded to two months of oral ferrous sulfate. Which management step is most appropriate?

  1. Reassure that dilutional anemia requires no treatment
  2. Switch to parenteral iron therapy Correct answer.
  3. Double the oral iron dose and add vitamin C
  4. Begin oral folic acid supplementation alone

Explanation

After bariatric surgery, particularly malabsorptive procedures, oral iron absorption is often impaired, so failure of an adequate oral trial warrants intravenous iron. Parenteral iron reliably repletes stores and is appropriate in pregnancy when oral therapy fails.

Question 29Maternal Medical Complications of Pregnancy

A 34-year-old woman at 30 weeks with long-standing type 1 diabetes has a fasting glucose of 95 mg/dL and a hemoglobin A1c of 6.4%. Which finding on fetal assessment most specifically reflects the chronic hyperinsulinemia associated with maternal hyperglycemia?

  1. Fetal macrosomia with abdominal circumference above the 90th percentile Correct answer.
  2. Isolated oligohydramnios
  3. Echogenic bowel
  4. Asymmetric growth restriction with a small abdominal circumference

Explanation

Maternal glucose crossing the placenta stimulates fetal insulin secretion, and insulin acts as a growth factor producing asymmetric overgrowth, especially of the trunk and abdominal circumference. This pattern is the sonographic hallmark of the hyperinsulinemic fetus in diabetic pregnancy.

Question 30Maternal Medical Complications of Pregnancy

A 37-year-old woman at 18 weeks with a mechanical mitral valve is being counseled about anticoagulation. She has been taking low-molecular-weight heparin and asks why warfarin is avoided. Which statement best characterizes the principal fetal risk of warfarin exposure at this gestational age?

  1. Low-molecular-weight heparin crosses the placenta and causes fetal anticoagulation
  2. Warfarin is safe for the fetus but causes maternal osteoporosis at high rates
  3. Warfarin exposure in the second trimester is associated with fetal renal agenesis
  4. Warfarin crosses the placenta and can cause fetal bleeding and embryopathy, whereas heparin does not cross the placenta Correct answer.

Explanation

Warfarin is a small molecule that crosses the placenta and can produce fetal anticoagulation, intracranial hemorrhage, and warfarin embryopathy, particularly with first-trimester exposure. Heparins are large molecules that do not cross the placenta, which is why they are used when fetal exposure must be avoided.

Question 31Fetal Complications and Fetal Therapy

Which fetal cardiac finding is most characteristic of a complete atrioventricular septal defect on prenatal ultrasound?

  1. Restrictive ventricular filling with a small, thick-walled left ventricle
  2. Isolated right ventricular hypertrophy with normal septa
  3. A common atrioventricular valve crossing the ventricular septum Correct answer.
  4. Pericardial effusion with a structurally normal four-chamber view

Explanation

A complete AVSD is defined by failure of the endocardial cushions to fuse, producing a single common AV valve and an ostium primum septal defect seen as a valve bridging the septal plane. This creates the classic 'crossing valve' appearance in the four-chamber view.

Question 32Fetal Complications and Fetal Therapy

Maternal serum alpha-fetoprotein is elevated in which of the following fetal conditions?

  1. Turner syndrome with hydrops
  2. Open neural tube defect Correct answer.
  3. Down syndrome
  4. Trisomy 18

Explanation

Open neural tube defects allow AFP to leak into amniotic fluid and then maternal serum, producing elevations. Aneuploidies such as trisomy 21 and 18 typically produce low AFP.

Question 33Fetal Complications and Fetal Therapy

A fetus with anencephaly is carried to term. Which neonatal outcome is expected?

  1. Normal survival with motor deficits only
  2. Death within hours to days after birth Correct answer.
  3. Survival requiring chronic ventilation
  4. Survival with severe intellectual disability

Explanation

Anencephaly is a fatal neural tube defect with absence of the forebrain and calvarium; affected neonates do not survive beyond a short period. Counseling should reflect this uniformly poor prognosis.

Question 34Fetal Complications and Fetal Therapy

Which intervention is the standard fetal therapy for severe twin-twin transfusion syndrome presenting before 26 weeks?

  1. Selective fetoscopic laser photocoagulation of placental anastomoses Correct answer.
  2. Maternal beta-blocker therapy
  3. Immediate delivery of both twins
  4. Serial amnioreduction alone

Explanation

Fetoscopic laser ablation of the communicating placental vessels addresses the underlying anastomoses and improves survival and neurologic outcomes compared with amnioreduction. It is preferred in Quintero stage II or greater before viability limits.

Question 35Fetal Complications and Fetal Therapy

Which finding defines Quintero stage I twin-twin transfusion syndrome?

  1. Polyhydramnios in the recipient with oligohydramnios in the donor and a visible bladder in the donor Correct answer.
  2. Hydrops in either twin
  3. Fetal demise of one twin
  4. Absent donor bladder with abnormal umbilical artery Doppler

Explanation

Quintero stage I consists of the amniotic fluid discordance (polyhydramnios/oligohydramnios) with the donor bladder still visible. Progressive stages add absent bladder, Doppler abnormalities, hydrops, and demise.

Question 36Fetal Complications and Fetal Therapy

Which congenital infection is most classically associated with ventriculomegaly, intracranial calcifications, and chorioretinitis?

  1. Cytomegalovirus Correct answer.
  2. Varicella-zoster virus
  3. Zika virus
  4. Parvovirus B19

Explanation

CMV is the leading cause of congenital infection and produces periventricular calcifications, ventriculomegaly, and chorioretinitis. The pattern reflects neurotropism for periventricular tissue.

Question 37Fetal Complications and Fetal Therapy

A fetus has a sacrococcygeal teratoma with rapid growth and high-output cardiac failure. Which mechanism best explains the hydrops?

  1. Direct obstruction of the inferior vena cava by the mass
  2. Vascular steal through the tumor causing high cardiac output and heart failure Correct answer.
  3. Hypoproteinemia from hepatic dysfunction
  4. Tumor secretion of antidiuretic hormone

Explanation

Large highly vascular SCTs act as arteriovenous shunts, producing high-output cardiac failure and hydrops. This is the rationale for prenatal intervention in selected cases.

Question 38Fetal Complications and Fetal Therapy

Which fetal arrhythmia is most commonly encountered prenatally?

  1. Atrial flutter
  2. Ventricular tachycardia
  3. Premature atrial contractions Correct answer.
  4. Complete heart block

Explanation

Premature atrial contractions are the most frequent fetal arrhythmia and are usually benign and self-limited. Sustained tachyarrhythmias and bradyarrhythmias are far less common.

Question 39Fetal Complications and Fetal Therapy

A 24-week fetus has severe immune hydrops with a middle cerebral artery peak systolic velocity above 1.5 multiples of the median. What is the most appropriate next step?

  1. Immediate cesarean delivery
  2. Maternal digoxin therapy
  3. Serial growth scans in 4 weeks
  4. Intrauterine intravascular transfusion Correct answer.

Explanation

An MCA-PSV above 1.5 MoM indicates severe fetal anemia, and in a hydropic fetus intravascular transfusion is indicated to correct anemia and treat hydrops. Delay risks fetal demise.

Question 40Fetal Complications and Fetal Therapy

Which finding on fetal MRI is most suggestive of congenital diaphragmatic hernia?

  1. Herniated bowel or liver into the hemithorax with mediastinal shift Correct answer.
  2. Bilateral enlarged ventricles
  3. Diffuse white matter T2 hyperintensity
  4. Absent cerebellar vermis

Explanation

CDH is diagnosed by herniation of abdominal contents into the chest with mediastinal shift and lung hypoplasia. MRI helps quantify lung volume and detect liver up.

Question 41Fetal Complications and Fetal Therapy

A fetus has a left-sided congenital diaphragmatic hernia with the liver up and a low observed-to-expected lung-to-head ratio. Which factor most strongly predicts poor outcome?

  1. Female fetal sex
  2. Liver herniation into the thorax Correct answer.
  3. Polyhydramnios alone
  4. Right-sided lesion location

Explanation

Intrathoracic liver herniation ('liver up') and low observed-to-expected LHR are the strongest prenatal predictors of mortality in CDH. They reflect greater visceral herniation and lung hypoplasia.

Question 42Fetal Complications and Fetal Therapy

Which prenatal ultrasound finding is most characteristic of a vein of Galen malformation?

  1. An echogenic focus in the left ventricle
  2. Bilateral renal cysts
  3. A midline cystic structure with high-velocity turbulent flow posterior to the third ventricle Correct answer.
  4. A single umbilical artery

Explanation

Vein of Galen malformation appears as a midline cystic mass with turbulent high-velocity flow from arteriovenous shunting. It can cause high-output cardiac failure and hydrops.

Question 43Fetal Complications and Fetal Therapy

A fetus with a large bronchopulmonary sequestration and evolving hydrops is being considered for therapy. Which intervention is most appropriate?

  1. Immediate delivery regardless of gestational age
  2. Maternal corticosteroid administration in selected cases or shunt/ablation therapy Correct answer.
  3. Amnioreduction alone
  4. Maternal antibiotic therapy

Explanation

Some microcystic lung lesions and sequestrations regress with maternal steroids, and hydropic cases may benefit from thoracoamniotic shunting or ablation of the feeding vessel. Management depends on lesion type and hydrops.

Question 44Fetal Complications and Fetal Therapy

Which ultrasound feature best distinguishes a congenital cystic adenomatoid malformation from a bronchopulmonary sequestration?

  1. Presence of polyhydramnios
  2. Location in the lower thorax
  3. Echogenicity of the mass
  4. Presence of a systemic feeding artery supplying the lesion Correct answer.

Explanation

A systemic arterial feeder from the aorta is the defining feature of a sequestration and is absent in CPAM. Color Doppler is used to identify this vessel.

Question 45Fetal Complications and Fetal Therapy

A fetus is diagnosed with a large ovarian cyst with a 'daughter cyst' appearance. What is the most likely diagnosis?

  1. Mesenteric cyst
  2. Simple functional ovarian cyst Correct answer.
  3. Choledochal cyst
  4. Sacrococcygeal teratoma

Explanation

A daughter cyst within a fetal pelvic cyst is characteristic of an ovarian cyst, thought to result from maternal hormonal stimulation. Most are simple and managed expectantly.

Question 46Fetal Complications and Fetal Therapy

A fetus has lower urinary tract obstruction with a keyhole bladder and oligohydramnios at 18 weeks. Which prognostic factor most strongly predicts renal outcome after vesicoamniotic shunting?

  1. Fetal urinary electrolytes and osmolality from vesicocentesis Correct answer.
  2. Amniotic fluid lecithin-sphingomyelin ratio
  3. Maternal blood pressure
  4. Fetal sex

Explanation

Fetal urine chemistries from vesicocentesis help predict residual renal function and select candidates for shunting. Favorable profiles suggest better post-shunt renal outcomes.

Question 47Fetal Complications and Fetal Therapy

Which finding is most consistent with a prenatal diagnosis of gastroschisis rather than omphalocele?

  1. Association with trisomy 18
  2. Free-floating bowel loops without a covering membrane, usually right of the umbilicus Correct answer.
  3. Bowel contained within a membrane at the umbilical cord insertion
  4. Liver within the herniated sac

Explanation

Gastroschisis is a full-thickness abdominal wall defect lateral to the umbilicus with free-floating bowel and no membrane. Omphalocele is midline, membrane-covered, and may contain liver.

Question 48Fetal Complications and Fetal Therapy

A monochorionic twin pregnancy shows a small donor with oligohydramnios and an absent bladder, and a recipient with polyhydramnios. Which additional finding would indicate Quintero stage III?

  1. Demise of the donor
  2. Polyhydramnios greater than 8 cm
  3. Absent end-diastolic flow in the donor umbilical artery Correct answer.
  4. Hydrops in the recipient

Explanation

Stage III is defined by abnormal Doppler findings such as absent or reversed end-diastolic flow in the umbilical artery, ductus venosus, or reversed flow in the ductus venosus. These indicate hemodynamic compromise.

Question 49Fetal Complications and Fetal Therapy

A fetus with suspected congenital toxoplasmosis is evaluated. Which maternal treatment is used to reduce vertical transmission after suspected acute infection?

  1. Spiramycin Correct answer.
  2. Metronidazole
  3. Acyclovir
  4. Amoxicillin

Explanation

Spiramycin is used in suspected maternal toxoplasmosis to reduce placental transmission; if fetal infection is confirmed, pyrimethamine and sulfadiazine are added after the first trimester.

Question 50Fetal Complications and Fetal Therapy

A fetus with a sacrococcygeal teratoma has a solid predominately external component and is growing rapidly. Which intervention is considered for a hydropic fetus before viability?

  1. Maternal chemotherapy
  2. Maternal bed rest alone
  3. Serial amniocentesis
  4. In utero tumor debulking or devascularization Correct answer.

Explanation

For rapidly growing vascular SCTs causing high-output failure, in utero resection or vascular ablation may be attempted to reverse hydrops. These are high-risk procedures reserved for selected cases.