Maternal-Fetal Medicine Practice Questions

Q: A woman at 26 weeks of gestation presents for routine evaluation. On examination, fundal height corresponds to 24 weeks. Ultrasonography revealed decreased amniotic fluid. Which of the following conditions would have led to this presentation?

Renal agenesis. ***Renal agenesis*** - **Renal agenesis** directly leads to **oligohydramnios** (decreased amniotic fluid) because fetal urine is the primary contributor to amniotic fluid volume after 20 weeks of gestation. - This reduction in amniotic fluid subsequently causes a **smaller fundal height** than expected for gestational age. *Tracheoesophageal fistula* - A **tracheoesophageal fistula** is primarily associated with **polyhydramnios** (excessive amniotic fluid) due to the fetus's inability to properly swallow amniotic fluid. - It would not lead to decreased amniotic fluid or a reduced fundal height. *Cardiac abnormalities* - **Cardiac abnormalities** can cause various fetal complications but are not typically a direct cause of **oligohydramnios**. - While severe cardiac issues can indirectly impact fetal growth, they usually do not lead to a significant reduction in amniotic fluid volume. *Ureteral stricture* - A **ureteral stricture** would impair urine flow from the kidney to the bladder, causing **hydronephrosis** of the affected kidney. - While it affects the renal system, if the other kidney is functioning, it generally would not lead to widespread **oligohydramnios** or a significantly reduced fundal height.

Q: Which of the following antihypertensive medications is not recommended for use in preeclampsia?

Atenolol. ***Atenolol*** - **Atenolol** is a **beta-blocker** that can cause **fetal growth restriction**, **bradycardia**, and **neonatal hypoglycemia**. - Its use during pregnancy, especially in preeclampsia, is generally **contraindicated** due to these adverse fetal effects. *Methyldopa* - **Methyldopa** is a **centrally acting alpha-2 adrenergic agonist** and is considered a **first-line agent** for chronic hypertension in pregnancy and preeclampsia. - It has a **proven safety record** for both mother and fetus, with few adverse effects. *Labetalol* - **Labetalol** is an **alpha and beta-blocker** commonly used in pregnancy for both chronic hypertension and acute severe hypertension in preeclampsia. - It is considered **safe and effective** for immediate blood pressure control without significant harm to the fetus. *Hydralazine* - **Hydralazine** is a **direct arterial vasodilator** frequently used for **acute severe hypertension** in preeclampsia and eclampsia. - It provides rapid blood pressure reduction and is considered a **safe option** for managing hypertensive emergencies in pregnancy.

Q: Which of the following is not a high-risk pregnancy?

Age 25-30 years. ***Age 25-30 years*** - An age of **25-30 years** is generally considered the optimal reproductive age range, and pregnancies within this bracket are typically classified as low-risk based on age alone. - This age range carries the lowest statistical risk for both maternal and fetal complications, assuming no other co-morbidities. *Previous history of manual removal of placenta* - A previous history of manual removal of the placenta indicates a risk factor for **recurrent placental retention** or **morbidly adherent placenta** in future pregnancies, making it a high-risk factor. - This history suggests an increased likelihood of complications such as **postpartum hemorrhage** and can influence the management of subsequent deliveries. *Anemia* - **Anemia** in pregnancy, especially severe iron deficiency anemia, is considered a high-risk factor due to increased maternal and fetal morbidity. - It can lead to complications such as **preterm delivery**, **low birth weight**, and difficulties tolerating blood loss during delivery. *Diabetes mellitus* - **Diabetes mellitus**, whether pre-existing or gestational, makes a pregnancy high-risk due to potential adverse effects on both the mother and the fetus. - Risks include **preeclampsia**, **macrosomia**, **neonatal hypoglycemia**, and **congenital anomalies**.

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: What size of Hegar's dilator, when passed through the internal os, indicates cervical incompetence?

8 or more. ***8 or more*** - The passage of a **Hegar's dilator of size 8 mm or larger** through the internal os without resistance is a classic diagnostic criterion for **cervical incompetence** or insufficiency. - This finding suggests a **weakened cervix** that is unable to withstand the pressure of a growing pregnancy, leading to recurrent mid-trimester pregnancy losses or preterm births. *4* - A Hegar's dilator of size 4 mm is relatively small and can often pass through a normal, non-pregnant **cervical os** without indicating pathology. - This size would not be considered abnormal and does not signify **cervical incompetence**. *6* - While a Hegar's dilator of 6 mm is larger than 4 mm, it is still generally within the range that might pass through a normal cervix, especially in **multiparous women**, without definitively diagnosing incompetence. - The threshold for diagnosing **cervical incompetence** is typically set higher, at 8 mm or more. *10* - While the passage of a 10 mm Hegar's dilator would certainly indicate **cervical incompetence**, the diagnostic cutoff is typically considered to be **8 mm or more**. - Any dilator **equal to or greater than 8 mm** confirms the diagnosis, so 10 mm is not the *only* size indicating incompetence.

Q: What is the recommended management for a patient with complete placenta previa at 38 weeks gestation without any vaginal bleeding?

Elective caesarean section. ***Elective caesarean section*** - For women with **complete placenta previa** at term (38 weeks), an **elective caesarean section** is the recommended mode of delivery to avoid significant hemorrhage. - Even in the absence of bleeding, the risk of massive hemorrhage during labor with a complete previa is high, necessitating planned surgical delivery. *Observation and monitoring until delivery* - This approach is not safe for complete placenta previa at term due to the high risk of **unpredictable, severe hemorrhage** once labor begins or the cervix dilates. - Active monitoring without planned intervention carries significant maternal and fetal risk. *Conservative management with bed rest* - While bed rest may be used in cases of **placenta previa with bleeding** earlier in gestation to prolong pregnancy, it does not address the fundamental risk of hemorrhage from a complete previa at 38 weeks. - It would not prevent the need for an eventual caesarean section and prolongs potential risks. *Urgent caesarean section due to bleeding risk* - While there is a bleeding risk, this scenario describes a patient at 38 weeks gestation **without any vaginal bleeding**, making it an elective, rather than urgent, situation. - An **urgent caesarean section** is typically reserved for cases where active bleeding or other obstetric emergencies are present.

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.

Question 1

A woman at 26 weeks of gestation presents for routine evaluation. On examination, fundal height corresponds to 24 weeks. Ultrasonography revealed decreased amniotic fluid. Which of the following conditions would have led to this presentation?

Accepted Answer

Renal agenesis

Answer

Tracheoesophageal fistula

Answer

Cardiac abnormalities

Answer

Ureteral stricture

Question 2

Which of the following antihypertensive medications is not recommended for use in preeclampsia?

Accepted Answer

Atenolol

Answer

Labetalol

Answer

Hydralazine

Answer

Methyldopa

Question 3

Which of the following is not a high-risk pregnancy?

Accepted Answer

Age 25-30 years

Answer

Diabetes mellitus

Answer

Previous history of manual removal of placenta

Answer

Anemia

Question 4

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 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

What size of Hegar's dilator, when passed through the internal os, indicates cervical incompetence?

Accepted Answer

8 or more

Answer

4

Answer

6

Answer

10

Question 8

What is the recommended management for a patient with complete placenta previa at 38 weeks gestation without any vaginal bleeding?

Accepted Answer

Elective caesarean section

Answer

Observation and monitoring until delivery

Answer

Conservative management with bed rest

Answer

Urgent caesarean section due to bleeding risk

Question 9

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 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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