Maternal-Fetal Medicine Practice Questions

Q: Which is not a risk factor for gestational hypertension

Smoking. ***Smoking*** - **Smoking** paradoxically shows a *protective effect* against gestational hypertension and preeclampsia, making it the correct answer as it is NOT a risk factor for gestational hypertension. - This well-documented phenomenon may be related to smoking's vasodilatory effects and reduced production of anti-angiogenic factors. - However, smoking carries numerous other serious risks including **intrauterine growth restriction (IUGR)**, **placental abruption**, **preterm birth**, and **perinatal mortality**. *Primigravida* - **Primigravida** (first pregnancy) is a well-established risk factor for gestational hypertension and preeclampsia. - First-time exposure to paternal antigens and incomplete immune tolerance may contribute to this increased risk. - The risk decreases in subsequent pregnancies with the same partner. *Factor V Leiden mutation* - The **Factor V Leiden mutation** is the most common inherited thrombophilia and significantly increases the risk of gestational hypertension and preeclampsia. - This mutation causes resistance to activated protein C, leading to a hypercoagulable state that can impair placental perfusion. - Associated with increased risk of venous thromboembolism during pregnancy. *Low maternal age* - **Low maternal age** (adolescent pregnancy, <20 years) is actually a recognized *risk factor* for gestational hypertension. - Young mothers may have incomplete physical and cardiovascular maturity to handle pregnancy-related physiological changes. - Adolescent pregnancies are associated with higher rates of hypertensive disorders of pregnancy.

Q: Common misdiagnosis of partial mole is

Threatened abortion. ***Threatened abortion*** - Partial moles often present with **vaginal bleeding** and a uterus size appropriate for gestational age, mimicking the symptoms of a **threatened abortion**. - **Fetal heartbeat** may be detectable in a partial mole, further complicating differentiation from a threatened abortion without detailed ultrasound or histological examination. *Choriocarcinoma* - **Choriocarcinoma** is a malignant tumor and a complication of molar pregnancy, not a common misdiagnosis of an early partial mole. - While both involve abnormal trophoblastic tissue, **choriocarcinoma** follows a molar pregnancy (or other gestations) and presents with systemic symptoms and very high hCG levels, distinct from the initial presentation of a partial mole. *Complete mole* - **Complete moles** are distinct from partial moles both genetically (46,XX or 46,XY with paternal origin only) and pathologically (no fetal tissue, generalized hydropic villi). - While both are types of molar pregnancy, they have different management and prognostic implications, and are distinct entities rather than a misdiagnosis of one for the other's initial presentation. *Ectopic pregnancy* - An **ectopic pregnancy** typically presents with pain and vaginal bleeding, along with an empty uterus on ultrasound. - While both involve abnormal pregnancy presentations, a **partial mole** usually shows some fetal tissue or identifiable placental tissue within the uterine cavity, distinguishing it from an ectopic pregnancy.

Q: Which of the following statements about chorionic villus sampling is false?

Is performed only in second trimester of pregnancy. ***Is performed only in second trimester of pregnancy*** - This statement is false because **chorionic villus sampling (CVS)** is typically performed earlier in pregnancy, specifically during the **first trimester**, usually between 10 and 13 weeks of gestation. - Performing CVS only in the second trimester would negate one of its main advantages: providing earlier genetic diagnostic information than **amniocentesis**. *Is used for prenatal genetic diagnosis* - **CVS** is a primary method for **prenatal genetic diagnosis**, allowing for the detection of chromosomal abnormalities and genetic disorders. - It involves analyzing fetal cells obtained from the **chorionic villi**. *Villi are collected from chorion frondosum* - The sample for **CVS** is indeed collected from the **chorion frondosum**, which is the fetal part of the placenta containing numerous chorionic villi. - These villi are genetically identical to the fetus, making them suitable for **genetic analysis**. *Can cause limb deformities* - There is a recognized, albeit small, risk of **limb reduction defects** associated with CVS, particularly if performed very early in gestation (before 9-10 weeks). - This risk is part of the counseling provided to prospective parents considering the procedure.

Q: In cervical incompetence, the diameter of the internal os of the cervix is typically greater than -

2.5 cm. ***2.5 cm*** * In **cervical incompetence**, the cervix prematurely dilates and effaces, often leading to second-trimester pregnancy loss or preterm birth. * A classic ultrasound finding suggestive of cervical incompetence is an internal os diameter greater than **2.5 cm** in the second trimester, in the absence of uterine contractions. *1 cm* * A normal internal os diameter is typically less than **1 cm**. A diameter of 1 cm would not be indicative of cervical incompetence without other clinical signs. * This measurement is within the **normal range** for a non-dilating cervix during pregnancy. *1.5 cm* * While 1.5 cm is larger than a typical closed os, it is generally not considered the definitive threshold for diagnosing **cervical incompetence** on its own. * The progression to a wider diameter, usually **2.5 cm or more**, is more clinically significant for diagnosis. *2 cm* * An internal os diameter of 2 cm may raise suspicion but is still often considered a **borderline finding**. * Many clinicians and guidelines use **2.5 cm as the more established cutoff** for identifying significant cervical incompetence.

Q: Most common antigen involved in erythroblastosis fetalis is:

D antigen in Rh group. ***D antigen in Rh group*** - The **D antigen** is the most immunogenic of the Rh antigens and is responsible for the vast majority of cases of **erythroblastosis fetalis** (hemolytic disease of the fetus and newborn). - When an **Rh-negative mother** is exposed to Rh-positive fetal blood (usually during previous pregnancies or transfusions), she can form antibodies against the D antigen, which can then cross the placenta in subsequent pregnancies and attack Rh-positive fetal red blood cells. *C antigen in Rh group* - While the **C antigen** is part of the Rh blood group system, antibodies to it are much less common and typically cause less severe hemolytic disease compared to anti-D antibodies. - The C antigen is less immunogenic than the D antigen, meaning it is less likely to provoke an immune response in an Rh-negative individual. *E antigen in Rh group* - Similar to the C antigen, the **E antigen** is another Rh antigen, but antibodies against it (anti-E) are also less frequently implicated in severe erythroblastosis fetalis than anti-D. - Antibodies to E can cause hemolytic disease, but their clinical significance is usually milder than that of anti-D. *Duffy antigen* - The **Duffy antigen system** is separate from the Rh system and is known for its role in resistance to certain malarial parasites (e.g., *Plasmodium vivax*). - Although antibodies to Duffy antigens (anti-Fya, anti-Fyb) can cause **hemolytic disease of the fetus/newborn**, they are a far less common cause of erythroblastosis fetalis than antibodies to the Rh D antigen.

Q: A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?

MCA Doppler. ***MCA Doppler*** - The presence of anti-D antibodies in a pregnant woman indicates **Rh isoimmunization**, which can lead to **hemolytic disease of the fetus and newborn (HDFN)**. - Even though a titre of **1:4 is below the critical threshold** (usually 1:16 or 1:32), any detectable anti-D titre at 28 weeks warrants **fetal surveillance** to detect early signs of fetal anemia. - **Middle cerebral artery (MCA) Doppler** is the **non-invasive gold standard** for detecting fetal anemia by measuring peak systolic velocity (PSV), which increases in anemic fetuses due to hyperdynamic circulation. - Serial MCA Doppler monitoring allows timely intervention if fetal anemia develops, avoiding unnecessary invasive procedures. *Caesarean section* - This is a mode of delivery and would only be considered if there were severe **fetal compromise** or other obstetric indications after proper monitoring and management. - At 28 weeks gestation with a low anti-D titre, immediate delivery is **not indicated** and would result in significant prematurity risks. *Induction of labour* - Induction of labour is a delivery method that would only be planned at term or for specific indications like severe fetal compromise unresponsive to other interventions. - At **28 weeks gestation**, the focus should be on **monitoring and prolonging pregnancy** while ensuring fetal wellbeing, not on delivery. *Amniocentesis* - Historically used to assess **bilirubin levels (ΔOD450)** in amniotic fluid as an indirect measure of fetal hemolysis, but it is an **invasive procedure** with risks (miscarriage ~1%, infection, worsening sensitization). - **MCA Doppler has largely replaced amniocentesis** for initial and serial assessment of fetal anemia due to its non-invasive nature, high sensitivity, and ability to be repeated safely.

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

Chorioangioma. ***Chorioangioma*** - A **chorioangioma** is a benign placental tumor that causes **polyhydramnios** (excess amniotic fluid), which is the **opposite** of oligohydramnios. - Large chorioangiomas lead to increased transudation from the tumor's vascular channels, fetal anemia, and high-output cardiac failure, resulting in increased fetal urine production. - This is clearly **NOT a cause** of oligohydramnios, making it the correct answer. *IUGR* - **Intrauterine growth restriction (IUGR)**, particularly with placental insufficiency, is a common cause of **oligohydramnios**. - Reduced placental perfusion leads to decreased **fetal renal blood flow** and diminished urine production. - Since fetal urine is the main source of amniotic fluid after 16 weeks, reduced output causes oligohydramnios. *Renal agenesis* - **Bilateral renal agenesis** (Potter syndrome) is a classic and severe cause of **oligohydramnios/anhydramnios**. - Complete absence of kidneys means **no fetal urine production**, eliminating the primary source of amniotic fluid in the second and third trimesters. - Results in severe oligohydramnios with associated pulmonary hypoplasia and Potter facies. *Amnion nodosum* - **Amnion nodosum** refers to small, grayish-yellow nodules on the fetal surface of the amnion, composed of aggregated fetal squamous epithelial cells and vernix. - These nodules are a **pathological finding** that occurs as a **consequence** of chronic oligohydramnios, not a cause. - They form due to prolonged contact between the fetal skin and amnion when amniotic fluid is severely reduced. - While technically "not a cause," it is strongly **associated with** oligohydramnios, whereas chorioangioma causes the opposite condition entirely.

Question 1

Which is not a risk factor for gestational hypertension

Accepted Answer

Smoking

Answer

Primigravida

Answer

Factor V Leiden mutation

Answer

Low maternal age

Question 2

Common misdiagnosis of partial mole is

Accepted Answer

Threatened abortion

Answer

Choriocarcinoma

Answer

Complete mole

Answer

Ectopic pregnancy

Question 3

Which of the following statements about chorionic villus sampling is false?

Accepted Answer

Is performed only in second trimester of pregnancy

Answer

Can cause limb deformities

Answer

Is used for prenatal genetic diagnosis

Answer

Villi are collected from chorion frondosum

Question 4

In cervical incompetence, the diameter of the internal os of the cervix is typically greater than -

Accepted Answer

2.5 cm

Answer

1 cm

Answer

1.5 cm

Answer

2 cm

Question 5

What is the best initial management option for ovarian ectopic pregnancy?

Accepted Answer

Surgical management (laparoscopy if stable, laparotomy if unstable)

Answer

Expectant management with serial monitoring

Answer

Emergency laparotomy in all cases

Answer

Medical management with methotrexate

Question 6

All are true about uteroplacental circulation except:

Accepted Answer

A mature placenta has 150 ml of blood in the villi system and 350 ml of blood in the intervillous space

Answer

The villi depend on the maternal blood for their nutrition

Answer

Blood in the intervillous space is completely replaced 3-4 times per minute

Answer

Intervillous blood flow at term is 500-600 ml per minute

Question 7

Most common antigen involved in erythroblastosis fetalis is:

Accepted Answer

D antigen in Rh group

Answer

C antigen in Rh group

Answer

E antigen in Rh group

Answer

Duffy antigen

Question 8

A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?

Accepted Answer

MCA Doppler

Answer

Caesarean section

Answer

Induction of labour

Answer

Amniocentesis

Question 9

Which of the following is NOT a cause of oligohydramnios?

Accepted Answer

Chorioangioma

Answer

Renal agenesis

Answer

Amnion nodosum

Answer

IUGR

Question 10

What is the most appropriate management for a 28-year-old hemodynamically stable patient with mild abdominal pain and an unruptured tubal ectopic pregnancy measuring 2.5 x 3 cm, with β-hCG level of 8500 mIU/mL, visible fetal cardiac activity, and who desires future fertility?

Accepted Answer

Laparoscopic salpingostomy

Answer

Methotrexate therapy

Answer

Laparoscopic salpingectomy

Answer

Expectant management

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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