Maternal-Fetal Medicine Practice Questions

Q: Oligohydramnios is seen in all except:

Rh incompatibility. **Explanation:** Amniotic fluid volume is primarily maintained by a balance between fetal urine production (the main source) and fetal swallowing (the main clearance). **Oligohydramnios** occurs when there is a decrease in production or an increase in loss/clearance. **Why Rh Incompatibility is the correct answer:** Rh isoimmunization typically leads to **Polyhydramnios**, not oligohydramnios. In severe Rh incompatibility, fetal anemia leads to high-output cardiac failure. This causes increased hydrostatic pressure and decreased oncotic pressure, resulting in fetal hydrops. The increased cardiac output leads to increased renal perfusion and excessive fetal urination, causing an increase in amniotic fluid volume. **Analysis of incorrect options:** * **Renal Agenesis (Potter’s Syndrome):** Since fetal urine is the primary source of amniotic fluid from the second trimester onwards, the absence of kidneys leads to severe, early-onset oligohydramnios. * **IUGR (Intrauterine Growth Restriction):** In placental insufficiency, the fetus redistributes blood flow to vital organs (brain-sparing effect) at the expense of the kidneys. Decreased renal perfusion leads to decreased urine output and oligohydramnios. * **Postmaturity:** After 40–42 weeks, placental function declines and the fetal glomerular filtration rate (GFR) naturally decreases, leading to a progressive reduction in amniotic fluid. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** Amniotic Fluid Index (AFI) < 5 cm or Single Deepest Pocket (SDP) < 2 cm. * **Most common cause of Oligohydramnios:** Premature Rupture of Membranes (PROM). * **Most common cause of Polyhydramnios:** Idiopathic (followed by Maternal Diabetes). * **Potter’s Sequence:** Oligohydramnios → Pulmonary hypoplasia, flattened facies, and limb deformities.

Q: Nonimmune hydrops fetalis is seen in all of the following conditions except?

Rh-incompatibility. ### Explanation Hydrops fetalis is defined as the abnormal accumulation of fluid in two or more fetal compartments (e.g., ascites, pleural effusion, pericardial effusion, or skin edema). It is categorized into two types: **Immune** and **Non-immune**. **1. Why Rh-incompatibility is the correct answer:** Rh-incompatibility is the classic cause of **Immune Hydrops Fetalis**. It occurs when an Rh-negative mother is sensitized to Rh-positive fetal red blood cells, leading to the production of IgG antibodies. These antibodies cross the placenta and cause immune-mediated hemolysis of fetal RBCs, resulting in severe anemia and subsequent heart failure. **2. Why the other options are incorrect (Causes of Non-immune Hydrops):** Non-immune hydrops (NIHF) accounts for nearly 90% of cases today due to the success of Rh-immunoglobulin prophylaxis. * **Alpha-thalassemia (Hb Bart’s):** This is the most common hematological cause of NIHF. The absence of alpha-globin chains leads to high-affinity hemoglobin that does not release oxygen to tissues, causing severe tissue hypoxia and high-output cardiac failure. * **Parvovirus B19:** This is the most common infectious cause of NIHF. The virus infects and destroys fetal erythroid progenitor cells, leading to aplastic anemia and hydrops. **Clinical Pearls for NEET-PG:** * **Most common cause of NIHF overall:** Cardiovascular anomalies (e.g., structural defects or arrhythmias). * **Most common chromosomal cause:** Turner Syndrome (45, XO) – often associated with cystic hygromas. * **Diagnosis:** Ultrasound is the gold standard; look for "Mirror Syndrome" (maternal edema mimicking fetal hydrops). * **Management of Rh-isoimmunization:** Monitored via MCA-PSV (Middle Cerebral Artery Peak Systolic Velocity) doppler to detect fetal anemia.

Q: A 33-year-old woman, gravida 3, para 2, aborta 0, presents at 9 weeks gestational age with a history of conization for CIN one year prior. She also has a history of preterm births at 30 and 32 weeks during her last two pregnancies. What is the best step in the management of this patient?

Cervical cerclage by 12 weeks. This patient presents with a classic history of **Cervical Insufficiency**. The diagnosis is based on her obstetric history (two prior spontaneous preterm births) and a significant risk factor (history of cervical conization). ### Why Option B is Correct In patients with a history of **two or more** prior spontaneous preterm births or second-trimester losses, a **History-Indicated Cerclage** (prophylactic) is recommended. This is typically performed between **12–14 weeks** of gestation, after confirming fetal viability and screening for chromosomal anomalies (e.g., NT scan). The goal is to provide mechanical support to a cervix weakened by prior surgical trauma (conization). ### Why Other Options are Incorrect * **Option A:** Ultrasound-indicated cerclage is reserved for women with a history of *one* prior preterm birth or those at risk who currently show cervical shortening (<25 mm). Since this patient has a high-risk history of *two* preterm births, waiting for ultrasound changes is inappropriate; she requires immediate prophylactic intervention. * **Option B:** Bed rest has not been proven to prevent preterm birth and increases the risk of venous thromboembolism (VTE) and bone demineralization. * **Option D:** Tocolysis is used to temporarily delay delivery in *acute* preterm labor (to allow for steroid administration); it has no role in the prophylactic management of cervical insufficiency. ### NEET-PG High-Yield Pearls * **Gold Standard Diagnosis:** History of painless cervical dilatation followed by second-trimester expulsion of the fetus. * **McDonald Cerclage:** A simple purse-string suture at the cervicovaginal junction (most common). * **Shirodkar Cerclage:** Submucosal dissection to place the suture higher at the internal os. * **Timing of Removal:** Cerclage is typically removed at **36–37 weeks** or if labor commences.

Q: Blastocyst implantation close to the internal os causes which of the following conditions?

Placenta previa. ### Explanation **1. Why Option A is Correct:** In a normal pregnancy, the blastocyst typically implants in the upper uterine segment (fundus). **Placenta previa** occurs when the blastocyst implants in the lower uterine segment, specifically near or over the **internal os** of the cervix. As the placenta develops in this low position, it may partially or completely cover the cervical opening, leading to the classic clinical presentation of painless, bright red vaginal bleeding in the third trimester. **2. Why Other Options are Incorrect:** * **Options B & C (Placenta Percreta/Increta):** These refer to **Placenta Accreta Spectrum (PAS)**, which is defined by the *depth of invasion* into the uterine wall, not the location relative to the os. * *Increta:* Villi invade the myometrium. * *Percreta:* Villi penetrate through the serosa and may involve adjacent organs (e.g., bladder). * **Option D (Abruptio Placentae):** This is the premature separation of a *normally situated* placenta from the uterine wall before delivery. It is characterized by painful vaginal bleeding and uterine tenderness. **3. High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Previous C-section (strongest risk for both Previa and Accreta), multiparity, and advanced maternal age. * **Diagnosis:** Transvaginal Ultrasound (TVS) is the gold standard for locating the placenta. * **Management Contraindication:** **Digital vaginal examination** is strictly contraindicated in suspected placenta previa until the diagnosis is ruled out, as it can provoke torrential hemorrhage (the "Stallworthy's sign" may be seen on examination). * **Classification:** The latest FIGO classification simplifies previa into "Placenta Previa" (covering the os) and "Low-lying Placenta" (edge <2cm from the os).

Q: Which of the following statements is false regarding vasa previa?

Maternal mortality is around 80%.. **Explanation:** **Vasa Previa** is a rare but life-threatening obstetric emergency where fetal vessels, unsupported by the umbilical cord or placental tissue, run through the fetal membranes across the internal os of the cervix. **1. Why Option A is the correct (False) statement:** The statement that maternal mortality is around 80% is **false**. In vasa previa, the bleeding is entirely **fetal** in origin. Because the total blood volume of a fetus is very small, even a minor bleed (e.g., 100ml) can lead to rapid fetal exsanguination and death (fetal mortality is high, often >50-70% if undiagnosed). However, since there is no maternal blood loss, the **maternal mortality is negligible (0%)**. **2. Analysis of other options:** * **Option B:** It is commonly associated with **velamentous insertion of the umbilical cord** or a **succenturiate lobe** of the placenta, where vessels must travel through the membranes to reach the main placental mass. * **Option C:** By definition, these are unprotected fetal vessels lying over the internal os, **below the presenting part**, making them vulnerable to rupture during the rupture of membranes (ROM). * **Option D:** The **Apt test** (alkali denaturation test) is used to differentiate fetal hemoglobin (HbF) from maternal hemoglobin (HbA). Since the bleeding in vasa previa is fetal, the Apt test will be positive (the solution remains pink), making it a diagnostic tool. **Clinical Pearls for NEET-PG:** * **Classic Triad:** Rupture of membranes + Painless vaginal bleeding + Fetal bradycardia/distress. * **Diagnosis:** Antenatally via **Transvaginal Color Doppler Ultrasound** (Gold Standard). * **Management:** If diagnosed prenatally, elective Cesarean section is planned at 34–36 weeks to avoid labor and ROM. If it occurs acutely during labor, immediate emergency Cesarean is mandatory.

Q: Large placenta is seen in all of the following conditions except?

Intrauterine Growth Restriction (IUGR). **Explanation:** The size and weight of the placenta are generally proportional to the size of the fetus. A **Large Placenta (Placentomegaly)** is typically defined as a placental thickness >4 cm or a weight exceeding the 90th percentile for gestational age. **1. Why IUGR is the correct answer:** In **Intrauterine Growth Restriction (IUGR)**, particularly placental-mediated IUGR (Type 2/Asymmetrical), there is **uteroplacental insufficiency**. This is characterized by poor trophoblastic invasion and reduced surface area for nutrient exchange, leading to a **small, shrunken, and infarcted placenta**. Since the question asks for the condition where a large placenta is *not* seen, IUGR is the correct choice. **2. Why the other options are incorrect:** * **Syphilis:** Congenital syphilis causes chronic villitis and edema of the placental villi, leading to a significantly enlarged, "pale," and "greasy" placenta. * **Cytomegalovirus (CMV) & Rubella:** These are part of the **TORCH infections**. Chronic intrauterine infections lead to inflammatory infiltration (villitis) and compensatory hyperplasia of the placental tissue, resulting in placentomegaly. **NEET-PG High-Yield Pearls:** * **Causes of Large Placenta:** Diabetes Mellitus (most common), Hydrops Fetalis (Immune/Non-immune), Syphilis, TORCH infections, Multiple gestations, and Chorioangioma. * **Causes of Small Placenta:** IUGR, Pre-eclampsia, Chronic Hypertension, and Chromosomal anomalies (e.g., Trisomy 18). * **Normal Placental Weight:** Approximately 1/6th of the baby's weight at term (approx. 500g). * **Placentomegaly on Ultrasound:** A thickness of **>40 mm** is a key diagnostic marker.

Q: Doppler ultrasonography in Intrauterine Growth Restriction (IUGR) and Preeclampsia shows a notch in which artery?

Uterine artery. **Explanation:** The correct answer is **B. Uterine artery**. In a normal pregnancy, trophoblastic invasion of the spiral arteries converts them from high-resistance, low-flow vessels into low-resistance, high-flow vessels. This process occurs in two waves (at 10–12 weeks and 16–20 weeks). If this invasion is defective, as seen in **Preeclampsia and Fetal Growth Restriction (FGR/IUGR)**, the uterine artery remains a high-resistance vessel. On Doppler, this high resistance manifests as an **early diastolic notch**. Persistence of this notch beyond **24 weeks** of gestation is a significant predictor of placental insufficiency, preeclampsia, and IUGR. **Analysis of Incorrect Options:** * **A. Umbilical artery:** Doppler changes here reflect fetal-placental resistance. In IUGR, we see increased resistance, reduced end-diastolic flow (REDF), or absent/reversed end-diastolic flow (AEDF/REDF), but **not** a diastolic notch. * **C. Internal iliac artery:** While the uterine artery is a branch of the internal iliac, the specific pathological changes related to placental perfusion are measured directly at the uterine artery. * **D. Vitelline artery:** This is an embryonic vessel associated with the yolk sac and is not used for monitoring IUGR or preeclampsia in clinical practice. **High-Yield Clinical Pearls for NEET-PG:** * **Uterine Artery Doppler:** Best for **screening** and predicting preeclampsia (High resistance = Notch). * **Umbilical Artery Doppler:** Best for **monitoring** a diagnosed case of IUGR and deciding the timing of delivery. * **Middle Cerebral Artery (MCA):** Shows "Brain Sparing Effect" (increased diastolic flow/low resistance) in IUGR. * **Ductus Venosus:** Abnormal flow (a-wave reversal) is a late sign of fetal cardiac failure and an indication for immediate delivery.

Q: At what gestational age should an uncomplicated triplet pregnancy be delivered?

34 weeks. **Explanation:** The timing of delivery in multiple gestations is a balance between the risks of prematurity and the increasing risk of stillbirth and placental insufficiency as the pregnancy progresses. **1. Why 34 weeks is correct:** For an **uncomplicated triplet pregnancy**, the risk of fetal demise increases significantly after 34 weeks. According to standard guidelines (ACOG and RCOG), elective delivery is recommended at **34 weeks 0 days**. At this stage, the benefits of avoiding potential intrauterine complications outweigh the neonatal risks associated with late preterm birth. Corticosteroids are typically administered prior to delivery to enhance fetal lung maturity. **2. Why the other options are incorrect:** * **35 weeks (Option B):** While only one week later, data shows a sharp rise in the risk of stillbirth in triplet pregnancies beyond the 34-week mark. * **37 weeks (Option C):** This is the recommendation for **uncomplicated twin pregnancies** (specifically dichorionic diamniotic twins). For triplets, 37 weeks is considered "post-term" due to extreme uterine distention and placental exhaustion. * **38 weeks (Option D):** This is the timing for a standard **singleton pregnancy**. Carrying triplets to this age poses a severe risk of maternal complications (preeclampsia, abruption) and fetal death. **High-Yield Clinical Pearls for NEET-PG:** * **Singleton:** 39–40 weeks. * **Twins (DCDA):** 37–38 weeks. * **Twins (MCDA):** 36–37 weeks. * **Twins (MCMA):** 32–34 weeks (delivered via Cesarean). * **Triplets:** 34 weeks. * **Mode of delivery for triplets:** Almost always **Cesarean section** due to the high risk of malpresentation and cord prolapse.

Question 1

Oligohydramnios is seen in all except:

Accepted Answer

Rh incompatibility

Answer

Renal agenesis

Answer

IUGR

Answer

Postmaturity

Question 2

Nonimmune hydrops fetalis is seen in all of the following conditions except?

Accepted Answer

Rh-incompatibility

Answer

Alpha-thalassemia

Answer

Parvovirus B19

Answer

All

Question 3

In a patient with Antiphospholipid Antibody syndrome, which of the following treatments is used to prevent further abortions?

Accepted Answer

Aspirin plus low molecular weight heparin

Answer

Corticosteroids

Answer

Intravenous immunoglobulins

Answer

Plasmapheresis

Question 4

A 33-year-old woman, gravida 3, para 2, aborta 0, presents at 9 weeks gestational age with a history of conization for CIN one year prior. She also has a history of preterm births at 30 and 32 weeks during her last two pregnancies. What is the best step in the management of this patient?

Accepted Answer

Cervical cerclage by 12 weeks

Answer

Ultrasound to assess cervical length and guide further management

Answer

Complete bed rest until viability is achieved

Answer

Low-dose tocolysis with salbutamol until viability is achieved

Question 5

Blastocyst implantation close to the internal os causes which of the following conditions?

Accepted Answer

Placenta previa

Answer

Placenta percreta

Answer

Placenta increta

Answer

Abruptio placentae

Question 6

Which of the following statements is false regarding vasa previa?

Accepted Answer

Maternal mortality is around 80%.

Answer

It is seen in velamentous insertion of the placenta.

Answer

Unprotected blood vessels lie below the presenting part.

Answer

The Apt test is diagnostic.

Question 7

Large placenta is seen in all of the following conditions except?

Accepted Answer

Intrauterine Growth Restriction (IUGR)

Answer

Syphilis

Answer

Cytomegalovirus (CMV) infection

Answer

Rubella infection

Question 8

Doppler ultrasonography in Intrauterine Growth Restriction (IUGR) and Preeclampsia shows a notch in which artery?

Accepted Answer

Uterine artery

Answer

Umbilical artery

Answer

Internal iliac artery

Answer

Vitelline artery

Question 9

At what gestational age should an uncomplicated triplet pregnancy be delivered?

Accepted Answer

34 weeks

Answer

35 weeks

Answer

37 weeks

Answer

38 weeks

Question 10

A 26-year-old primigravida with a twin gestation at 30 weeks presents for a USG. The sonogram indicates that the fetuses are both male and the placenta appears to be diamniotic and monochorionic. Twin B is noted to have oligohydramnios and to be much smaller than twin A. In this clinical scenario, all of the following are concerns for twin A except?

Accepted Answer

Anemia

Answer

Congestive heart failure (CHF)

Answer

Hydramnios

Answer

Widespread thromboses

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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