Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 1221: 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?

A. Renal agenesis (Correct Answer)
B. Tracheoesophageal fistula
C. Cardiac abnormalities
D. Ureteral stricture

Explanation: ***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.

Question 1222: Which of the following is the MOST significant physiological change that occurs during pregnancy?

A. Increase total protein
B. Increase GFR
C. Increase residual volume
D. Increase cardiac output (Correct Answer)

Explanation: ***Increase cardiac output*** - **Cardiac output** significantly increases during pregnancy, starting in the first trimester and peaking in the third trimester. This is to meet the increased metabolic demands of the growing fetus, placenta, and maternal organs. - This increase is primarily due to an increase in **stroke volume** and **heart rate**, crucial for maintaining adequate uteroplacental perfusion. *Increase total protein* - While total blood volume increases during pregnancy, **plasma volume** increases disproportionately more than red blood cell mass, leading to hemodilution. - This hemodilution generally causes a *decrease* in total serum protein concentration and albumin levels, rather than an increase. *Increase residual volume* - **Residual volume** (the volume of air remaining in the lungs after maximal exhalation) actually *decreases* during pregnancy. - This decrease is due to the upward displacement of the diaphragm by the gravid uterus and an increase in inspiratory capacity, not an increase in residual volume. *Increase GFR* - **Glomerular filtration rate (GFR)** does significantly increase during pregnancy, often by 30-50% by the second trimester, in response to increased renal blood flow. - While important, the increase in GFR is a consequence of the systemic hemodynamic changes (including increased cardiac output) and is not as *overall* physiologically significant as the **fundamental increase in cardiac output** that drives many other physiological adaptations.

Question 1223: Which of the following statement is correct about acute fatty liver of pregnancy?

A. Mostly seen in last trimester (Correct Answer)
B. May be associated with decreased uric acid
C. Occurs in 1 in 1000 pregnancies
D. Not related to the gender of the fetus

Explanation: ***Mostly seen in last trimester*** - **Acute fatty liver of pregnancy (AFLP)** typically manifests in the **third trimester** (weeks 28-40) of gestation or in the immediate postpartum period. - This timing is due to the increased metabolic demands on the liver during late pregnancy, which can exacerbate underlying defects in mitochondrial fatty acid oxidation. *Occurs in 1 in 1000 pregnancies* - AFLP is a **rare** obstetric complication, occurring in approximately **1 in 7,000 to 1 in 16,000** pregnancies, not 1 in 1000. - The incidence of 1 in 1000 would make it far too common and is incorrect. *Not related to the gender of the fetus* - AFLP has been observed to have a higher incidence in pregnancies involving a **male fetus**. - This association is thought to be related to differences in fetal steroid metabolism or the demands placed on maternal liver function by the male fetus. *May be associated with decreased uric acid* - AFLP is typically associated with **elevated serum uric acid levels** (hyperuricemia), not decreased levels. - Other typical findings include elevated liver enzymes, bilirubin, and sometimes severe hypoglycemia.

Question 1224: A baby born at 34 weeks gestation weighs 3kg. Which of the following conditions is this child most likely to develop in the immediate postnatal period?

A. APH
B. Diabetes
C. Anemia (Correct Answer)
D. None of the options

Explanation: ***Anemia*** - Macrosomic babies (3kg at 34 weeks is **large for gestational age**) initially develop **polycythemia** due to chronic intrauterine hypoxia and increased erythropoiesis, but this is followed by rapid **hemolysis** and breakdown of excess red blood cells after birth, leading to anemia in the immediate postnatal period. - Among the given options, **anemia** is the most appropriate answer as it represents a recognized complication of LGA babies through the **polycythemia-hemolysis cycle**, even though **hypoglycemia** is statistically the most common immediate complication. *APH* - **Antepartum hemorrhage (APH)** is a maternal obstetric complication involving bleeding before delivery, not a condition that the baby itself develops or shows. - While APH can affect fetal growth and well-being, it is not a **neonatal condition** that the child would present with after birth. *Diabetes* - Although **maternal diabetes** is the most common cause of fetal macrosomia, the newborn does not develop diabetes itself in the immediate postnatal period. - Instead, these babies are at risk for **hypoglycemia**, **respiratory distress**, and **hyperbilirubinemia** due to fetal hyperinsulinemia, but not diabetes as a presenting condition. *None of the options* - This is incorrect because **anemia** is indeed a valid condition that macrosomic babies can develop through the described polycythemia-hemolysis mechanism. - While other complications like **hypoglycemia** and **birth trauma** are more common, anemia remains a recognized sequela among LGA babies in the immediate postnatal period.

Question 1225: The major contributor to amniotic fluid after 20 weeks of gestation is:

A. Fetal urine (Correct Answer)
B. Fetal skin
C. Ultrafiltrate of maternal plasma
D. Fluid from fetal lungs

Explanation: ***Fetal urine*** - After **20 weeks of gestation**, the **fetal kidneys** are fully functional, and fetal urination becomes the primary source of amniotic fluid. - This contribution is crucial for the **volume of amniotic fluid** and plays a vital role in **fetal lung development** by allowing the fetus to "breathe" the fluid. *Ultrafiltrate of maternal plasma* - While an ultrafiltrate of maternal plasma contributes to the early amniotic fluid volume, its significance diminishes as the **fetal kidneys mature** past 20 weeks. - This source primarily provides water and dissolved solutes, but not a substantial volume. *Fluid from fetal lungs* - Fluid produced by the fetal lungs also contributes to amniotic fluid, but its volume is considerably smaller than that from **fetal urine**, especially after 20 weeks. - It mainly includes pulmonary surfactants and other specific proteins important for lung maturation. *Fetal skin* - Before **keratinization** of the fetal skin (around 20-22 weeks), the skin is permeable and allows for transepidermal fluid transport, contributing to amniotic fluid. - However, once **keratinization** is complete, the skin becomes impermeable, and its contribution to amniotic fluid becomes negligible.

Question 1226: Which of the following is not a high-risk pregnancy?

A. Age 25-30 years (Correct Answer)
B. Diabetes mellitus
C. Previous history of manual removal of placenta
D. Anemia

Explanation: ***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**.

Question 1227: Which of the following antihypertensive medications is not recommended for use in preeclampsia?

A. Labetalol
B. Hydralazine
C. Methyldopa
D. Atenolol (Correct Answer)

Explanation: ***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.

Question 1228: What size of Hegar's dilator, when passed through the internal os, indicates cervical incompetence?

A. 4
B. 6
C. 10
D. 8 or more (Correct Answer)

Explanation: ***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.

Question 1229: Which of the following conditions is ruled out in a twin pregnancy of the same age and sex?

A. Monozygotic twins
B. Superfetation (Correct Answer)
C. Superfecundation
D. None of the following

Explanation: ***Superfetation*** - **Superfetation** refers to the fertilization of an ovum when another pregnancy is already established in the uterus, resulting in two fetuses of **different gestational ages**. - As the question specifies a twin pregnancy of the **same age**, superfetation is ruled out. *Monozygotic twins* - **Monozygotic twins** originate from a single zygote that splits, resulting in genetically identical individuals of the **same sex** and age. - This condition is consistent with the given scenario of same-sex, same-aged twins. *Superfecundation* - **Superfecundation** is the fertilization of two or more ova from the same ovulatory cycle by sperm from **different acts of coitus** (which may involve different partners). - The twins are of the **same gestational age** (same cycle) but are **dizygotic**, and can be either the same sex or different sexes. - This condition is NOT ruled out by the criteria given in the question. *None of the following* - This option is incorrect because **superfetation** is definitively ruled out by the criteria of the question (twins of the same age).

Question 1230: Which of the following is not associated with maternal age?

A. Preterm labour
B. Aneuploidy
C. Hydatidiform mole
D. Post maturity (Correct Answer)

Explanation: ***Post maturity*** - **Post-maturity** (post-term pregnancy, >42 weeks) does NOT have a consistent or strong association with maternal age in current obstetric literature. - While some older studies suggested associations, modern evidence shows **no significant independent effect of maternal age** on post-term pregnancy rates. - Post-term pregnancy is more related to factors like **first pregnancy**, **prior post-term delivery**, and **fetal sex** (males more common). *Preterm labour* - **Preterm birth is strongly associated with maternal age**, particularly at both extremes: - **Teenage mothers** (<20 years): Increased risk due to biological immaturity and socioeconomic factors - **Advanced maternal age** (≥35 years): Increased risk due to higher rates of maternal complications (hypertension, diabetes) and placental dysfunction - This is well-established in obstetric literature and clinical guidelines. *Aneuploidy* - The risk of **aneuploidy**, particularly **Down syndrome (Trisomy 21)**, **increases dramatically with advancing maternal age**. - At age 35: ~1/350 risk; at age 40: ~1/100 risk; at age 45: ~1/30 risk - Due to age-related decline in oocyte quality causing meiotic errors during egg formation. *Hydatidiform mole* - **Gestational trophoblastic disease** (hydatidiform mole) is strongly associated with **extremes of maternal age**: - **Women >40 years**: 5-10 fold increased risk - **Teenagers**: 1.5-2 fold increased risk - Related to abnormal fertilization events more common at age extremes.

Practice by Chapter

Fetal Assessment Techniques

Practice Questions

Hypertensive Disorders in Pregnancy

Practice Questions

Intrauterine Growth Restriction

Practice Questions

Multiple Gestation

Practice Questions

Rh Isoimmunization and Other Blood Group Incompatibilities

Practice Questions

Intrauterine Fetal Therapy

Practice Questions

Prenatal Diagnosis and Genetic Counseling

Practice Questions

Placental Abnormalities

Practice Questions

Preterm Labor and Delivery

Practice Questions

Management of Medical Disorders in Pregnancy

Practice Questions

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