Maternal-Fetal Medicine Practice Questions

Q: Anencephaly can be diagnosed by ultrasound (USG) at

14-18 weeks of gestation. ***14-18 weeks of gestation*** - **Anencephaly**, characterized by the absence of a major portion of the brain and skull, can be reliably diagnosed by **ultrasound (USG)** during this gestational period. - At this stage, the fetal head structures are sufficiently developed to clearly visualize the **absence of the cranium and cerebral hemispheres**. *10-12 weeks of gestation* - While some gross anomalies might be suspected, the developing fetal skull and brain are often **too small** for a definitive diagnosis of anencephaly. - The **ossification of the calvaria** (skull bones) is still incomplete, making it difficult to confidently identify its absence. *20-24 weeks of gestation* - Anencephaly would be clearly detectable by this stage, but it is **later than the optimal window** for early diagnosis and intervention, if desired. - Many screening programs aim for diagnosis before this period to allow for more options for parental decision-making. *24-28 weeks of gestation* - At this advanced stage, the diagnosis of anencephaly would be evident, but it represents a **significantly delayed diagnosis** given the availability of earlier screening methods. - The primary purpose of **antenatal screening** is to detect such severe congenital anomalies in the mid-trimester.

Q: What is the most specific use of Doppler ultrasound in twin pregnancies?

Assessing twin-to-twin transfusion syndrome. ***Assessing twin-to-twin transfusion syndrome (TTTS)*** - Doppler ultrasound is crucial for diagnosing and monitoring **TTTS** by evaluating blood flow in the umbilical arteries and veins, and assessing fetal cardiac output and venous flow patterns. - It helps detect the characteristic signs of **TTTS**, such as unequal blood flow between twins and abnormal Doppler indices in the umbilical and middle cerebral arteries, guiding timely intervention. *Evaluating conjoined twins* - While ultrasound identifies **conjoined twins** and their anatomical connections, Doppler primarily assesses blood flow, not the structural fusion itself. - 2D and 3D ultrasound are more directly used for the anatomical evaluation of the degree and type of organ sharing in **conjoined twins**. *Monitoring fetal well-being in twins* - Though Doppler can contribute to **fetal well-being assessment** through blood flow analysis, its primary and most specific role in twin pregnancies is the diagnosis and management of **TTTS**. - Other parameters like **biophysical profile** and growth scans are also vital for general fetal well-being in twins. *All of the options* - This option is incorrect because while Doppler ultrasound might be part of a broader assessment in some scenarios, its most significant and specific application in twin pregnancies is for **TTTS**. - Its role in the direct evaluation of conjoined twin anatomy or general fetal well-being is secondary to specialized applications like **TTTS** diagnosis.

Q: Which type of eclampsia has the worst prognosis?

Late postpartum. ***Late postpartum*** - **Late postpartum eclampsia**, occurring more than 48 hours after delivery, often presents with a poorer prognosis due to delayed diagnosis and potential for more severe complications, such as **cerebral hemorrhage** or **status epilepticus**, as patients may no longer be under close medical supervision. - The delayed onset can lead to misinterpretation of symptoms, making treatment less timely and effective, thus contributing to higher rates of morbidity and mortality. *Antepartum* - **Antepartum eclampsia** occurs before labor and while serious, is often detected when the patient is under medical care for preeclampsia, allowing for earlier intervention and management. - Although it can lead to complications such as **placental abruption** and **fetal distress**, the mother is typically in a healthcare setting, which facilitates immediate care. *Early postpartum* - **Early postpartum eclampsia** occurs within 48 hours after delivery, and while still critical, is usually managed in the hospital setting where medical attention is readily available, allowing for prompt treatment of seizures and associated complications. - The patient remains under close observation during this period, enabling quick response to emergent conditions. *Intrapartum* - **Intrapartum eclampsia** occurs during labor and delivery, and like early postpartum eclampsia, benefits from the patient being in a hospital environment with immediate access to medical personnel and emergency interventions. - The prompt recognition and management of seizures during childbirth can help mitigate severe outcomes for both mother and baby.

Q: Lowest frequency of twin pregnancy is seen in:

Japan. ***Japan*** - **Japan** has one of the **lowest rates of twin pregnancies globally**, characterized by a low incidence of both **monozygotic** and **dizygotic twins**. This is attributed to genetic predisposition and potentially lower use of assisted reproductive technologies. - The population's genetic background and reproductive practices contribute to the observed lower twinning rates compared to other regions. *Nigeria* - **Nigeria** has the **highest frequency of twin pregnancies in the world**, with birth rates significantly higher than the global average, particularly in certain ethnic groups like the **Yoruba**. - This high rate is primarily due to a genetic predisposition to **dizygotic twinning**, linked to specific dietary and genetic factors. *Philippines* - The **Philippines** has a relatively **moderate to high frequency of twin pregnancies** compared to some other Asian countries, though not as high as countries in Africa. - Genetic and possibly some socio-economic factors contribute to its twinning rate, which is higher than the lowest observed rates. *India* - **India** generally exhibits a **lower to moderate frequency of twin pregnancies** compared to African nations, but often higher than some East Asian countries. - While regional variations exist, the overall rate is influenced by a mix of genetic factors and the increasing, but still relatively limited, use of **assisted reproductive technologies (ART)**.

Q: What is the critical value of the shock index that is considered abnormal in pregnancy?

0.9-1.1. ***0.9-1.1*** - A **shock index (heart rate/systolic blood pressure) of 0.9 or greater** is considered abnormal and a critical value in pregnant patients. - This elevated threshold indicates a significant risk of **hypovolemia and hemodynamic compromise**, which might be masked by the physiological changes of pregnancy. - Values ≥0.9 suggest that compensatory mechanisms are failing and require **immediate clinical intervention**. *0.5-0.7* - This range represents a **normal shock index for non-pregnant adults**. - Due to the **physiological hypervolemia and cardiovascular adaptations** of pregnancy, vital signs can remain deceptively stable even with significant blood loss, making this range inappropriately low for identifying shock in pregnant patients. *0.3-0.5* - A shock index within this range is considered **low** and generally indicative of a well-perfused state in non-pregnant individuals. - It does not reflect the **baseline physiological changes** seen in pregnancy and would miss critical hemodynamic compromise in obstetric emergencies. *0.7-0.9* - While this range may indicate mild elevation approaching abnormal values, it falls **below the established critical threshold of 0.9** for pregnancy. - The critical cutoff is specifically set at **≥0.9** to ensure **early detection and intervention** for maternal hemodynamic compromise before decompensation occurs.

Q: At what gestational age is transabdominal color Doppler sonography optimally performed to assess fetal well-being?

18-20 weeks. ***18-20 weeks*** - This gestational age is ideal for a **detailed anatomical survey** and assessing fetal well-being using **transabdominal color Doppler sonography**. - At this stage, fetal structures are well-developed, and the **fetus is large enough** for accurate assessment of blood flow in various vessels. *11-13 weeks* - This period is primarily for **nuchal translucency** screening and early structural assessment, but fetal vessels are generally too small for optimal Doppler flow studies. - While some early Doppler studies can be done, a comprehensive assessment of fetal well-being is usually not achieved. *Done before 10 weeks* - Before 10 weeks, the embryo/fetus is **too small** for a detailed anatomical survey or meaningful Doppler assessment of most vessels. - Doppler studies at this stage are usually limited to confirming viability via **heartbeat.** *5-7 weeks* - This is a very early stage of pregnancy where the primary goal of sonography is to confirm **intrauterine pregnancy**, **fetal viability**, and estimate gestational age. - **Fetal anatomical structures** are not yet sufficiently developed for detailed assessment or Doppler studies of most circulatory components.

Q: A pregnant patient with a prosthetic valve on warfarin should be switched to heparin at

36 weeks. ***36 weeks*** - At **36 weeks of gestation**, a pregnant patient on **warfarin** (due to a prosthetic valve) should be switched to **unfractionated heparin (UFH)** or **low molecular weight heparin (LMWH)**. - This timing is crucial to mitigate the risk of fetal coagulopathy from warfarin exposure during delivery and to allow for safer management of anticoagulation during labor and delivery. *30 weeks* - Switching to heparin at 30 weeks is generally too early and unnecessarily prolongs the period of subcutaneous injections, which can be burdensome for patients. - The primary concern of fetal coagulopathy with warfarin is highest closer to term, making a switch at 36 weeks more appropriate for balancing maternal and fetal risks. *38 weeks* - Switching at 38 weeks significantly increases the risk that labor might occur while the patient is still on warfarin, exposing the fetus to the drug and increasing the risk of maternal bleeding complications during delivery. - It leaves little buffer time for the warfarin's effects to wear off before spontaneous labor might begin. *Onset of labour* - Waiting until the onset of labor to switch from warfarin to heparin is dangerous and inappropriate. - Warfarin has a long half-life, and its anticoagulant effects would still be present during labor and delivery, posing a high risk of fetal hemorrhage (especially intracranial hemorrhage) and significant maternal bleeding.

Q: Following tests are done for assessing fetal lung maturity. Which of the following test results does not indicate adequate fetal lung maturity?

Lecithin/sphingomyelin ratio less than 2. ***Lecithin/sphingomyelin ratio less than 2*** - A **lecithin/sphingomyelin (L/S) ratio** of **less than 2:1** indicates a higher risk of respiratory distress syndrome (RDS) due to insufficient **surfactant** production. - Surfactant is crucial for reducing surface tension in the alveoli, preventing their collapse at the end of expiration. - An L/S ratio **≥2:1** is considered indicative of fetal lung maturity. *Foam stability index greater than 47* - A **foam stability index (FSI) greater than or equal to 47** indicates the presence of sufficient **surfactant** to create stable foam, suggesting **fetal lung maturity**. - This test is based on the ability of surfactant to reduce surface tension in amniotic fluid when mixed with ethanol. *Presence of phosphatidylglycerol* - The **presence of phosphatidylglycerol (PG)** in the amniotic fluid is a strong indicator of **fetal lung maturity**. - PG is a mature **surfactant** component that appears later in gestation and signifies a very low risk of respiratory distress syndrome (RDS). *Optical density at 650 nm less than 0.15* - An **optical density (OD) at 650 nm of less than 0.15** in the amniotic fluid indicates **fetal lung maturity**. - This test measures the turbidity of amniotic fluid, with lower values indicating the presence of mature surfactant and clear fluid.

Q: What are the potential complications in subsequent pregnancies for a woman with a history of gestational trophoblastic disease?

Increased risk of recurrent GTD and pregnancy complications. ***Increased risk of recurrent GTD and pregnancy complications*** - A history of **gestational trophoblastic disease (GTD)** significantly increases the risk of recurrence in subsequent pregnancies, emphasizing the need for close monitoring. - There is also an elevated risk of other **adverse pregnancy outcomes**, including **preterm birth** and **preeclampsia**, following a GTD history. *Neural tube defects* - **Neural tube defects** are congenital anomalies primarily associated with **folate deficiency** and genetic factors, not a prior history of GTD. - They involve incomplete closure of the neural tube during embryonic development, unrelated to trophoblastic tissue. *Cardiac defects* - **Congenital cardiac defects** are multifactorial, linked to genetic predisposition, maternal conditions like **diabetes**, and certain exposures, but not a history of GTD. - They result from abnormal heart development in the early stages of pregnancy. *Skeletal defects* - **Skeletal defects** can be hereditary or related to maternal infections (e.g., rubella), drug exposure (e.g., thalidomide), or specific genetic syndromes, not GTD. - These malformations occur during fetal bone and limb development.

Question 1

Anencephaly can be diagnosed by ultrasound (USG) at

Accepted Answer

14-18 weeks of gestation

Answer

20-24 weeks of gestation

Answer

24-28 weeks of gestation

Answer

10-12 weeks of gestation

Question 2

What is the most specific use of Doppler ultrasound in twin pregnancies?

Accepted Answer

Assessing twin-to-twin transfusion syndrome

Answer

Evaluating conjoined twins

Answer

Monitoring fetal well-being in twins

Answer

All of the options

Question 3

Which type of eclampsia has the worst prognosis?

Accepted Answer

Late postpartum

Answer

Early postpartum

Answer

Intrapartum

Answer

Antepartum

Question 4

Lowest frequency of twin pregnancy is seen in:

Accepted Answer

Japan

Answer

Philippines

Answer

India

Answer

Nigeria

Question 5

What is the critical value of the shock index that is considered abnormal in pregnancy?

Accepted Answer

0.9-1.1

Answer

0.3-0.5

Answer

0.7-0.9

Answer

0.5-0.7

Question 6

At what gestational age is transabdominal color Doppler sonography optimally performed to assess fetal well-being?

Accepted Answer

18-20 weeks

Answer

Done before 10 weeks

Answer

11-13 weeks

Answer

5-7 weeks

Question 7

Which of the following statements regarding the umbilical cord is true?

Accepted Answer

Observation of a single umbilical artery is associated with additional anomalies

Answer

Two arteries and two veins

Answer

One artery and two veins

Answer

Observation of a single umbilical vein is associated with additional anomalies

Question 8

A pregnant patient with a prosthetic valve on warfarin should be switched to heparin at

Accepted Answer

36 weeks

Answer

Onset of labour

Answer

30 weeks

Answer

38 weeks

Question 9

Following tests are done for assessing fetal lung maturity. Which of the following test results does not indicate adequate fetal lung maturity?

Accepted Answer

Lecithin/sphingomyelin ratio less than 2

Answer

Foam stability index greater than 47

Answer

Presence of phosphatidylglycerol

Answer

Optical density at 650 nm less than 0.15

Question 10

What are the potential complications in subsequent pregnancies for a woman with a history of gestational trophoblastic disease?

Accepted Answer

Increased risk of recurrent GTD and pregnancy complications

Answer

Neural tube defects

Answer

Skeletal defects

Answer

Cardiac defects

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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