LE3 Reviewer POST-Term Flashcards
Which of the following cytokines is most commonly involved in infection-driven inflammation that leads to spontaneous preterm labor?
A. IL-1
B. IL-2
C. IL-4
D. TNF-β
A. IL-1
Discussion: IL-1 is a pro-inflammatory cytokine that plays a key role in the inflammatory response associated with spontaneous preterm labor. Infection in the genital tract can lead to an increase in IL-1, which stimulates the production of prostaglandins, leading to uterine contractions, cervical ripening, and membrane rupture.
Which condition increases mechanical stress on the uterus and may lead to preterm labor due to overdistension?
A. Oligohydramnios
B. Polyhydramnios
C. Placenta previa
D. Cervical incompetence
B. Polyhydramnios
Discussion: Polyhydramnios refers to an excessive amount of amniotic fluid, which can lead to overdistension of the uterus. This increased mechanical stress can trigger uterine contractions and lead to preterm labor. Multiple gestation and certain fetal anomalies can also contribute to overdistension.
The release of thrombin during decidual hemorrhage leads to which of the following actions in the context of preterm labor?
A. Inhibits prostaglandin production
B. Increases protease activity and matrix degradation
C. Increases progesterone action
D. Stimulates uterine relaxation
B. Increases protease activity and matrix degradation
Discussion: Decidual hemorrhage can lead to the release of thrombin, which in turn activates proteases that degrade the extracellular matrix. This weakening of the fetal membranes can lead to their rupture and the onset of preterm labor.
Activation of the maternal or fetal hypothalamic-pituitary-adrenal (HPA) axis can lead to increased production of which hormone, contributing to preterm labor?
A. Corticotropin-releasing hormone (CRH)
B. Oxytocin
C. Progesterone
D. Estrogen
A. Corticotropin-releasing hormone (CRH)
Discussion: Activation of the HPA axis, often due to maternal or fetal stress, leads to increased production of CRH. Elevated CRH levels stimulate the production of prostaglandins, which promote uterine contractions and cervical ripening, contributing to preterm labor.
Premature rupture of membranes (PROM) is primarily caused by which of the following mechanisms?
A. Increased collagen synthesis
B. Increased matrix metalloproteinase (MMP) activity
C. Increased oxytocin production
D. Decreased amniotic fluid volume
B. Increased matrix metalloproteinase (MMP) activity
Discussion: PROM occurs when the fetal membranes rupture before labor begins. Increased MMP activity leads to the breakdown of collagen in the membranes, weakening them and making them more prone to rupture, which can result in PROM and potentially preterm labor.
Case Scenario: A 28-year-old woman at 30 weeks gestation presents with painful contractions and lower abdominal discomfort. On examination, she is found to have cervical dilation and evidence of chorioamnionitis. The patient reports a recent history of urinary tract infection.
Question: What is the most likely mechanism leading to her preterm labor?
A. Overdistension of the uterus
B. Infection and inflammation with release of pro-inflammatory cytokines
C. Activation of the HPA axis
D. Genetic predisposition
B. Infection and inflammation with release of pro-inflammatory cytokines
Discussion: Chorioamnionitis is an intrauterine infection that triggers an inflammatory response. The release of pro-inflammatory cytokines, such as IL-1 and TNF-α, leads to increased prostaglandin production, which promotes uterine contractions and cervical changes, ultimately resulting in preterm labor.
Case Scenario: A 32-year-old pregnant woman, carrying twins, presents at 29 weeks gestation with regular uterine contractions. Ultrasound examination reveals polyhydramnios.
Question: Which mechanism is most likely responsible for the onset of her preterm labor?
A. Activation of the maternal HPA axis
B. Overdistension of the uterus
C. Decidual hemorrhage
D. Genetic predisposition
B. Overdistension of the uterus
Discussion: The presence of polyhydramnios, especially in a multiple gestation pregnancy, leads to overdistension of the uterus. This increased mechanical stress can initiate uterine contractions and result in preterm labor.
A 24-year-old pregnant woman at 33 weeks presents with painless vaginal bleeding. Ultrasound shows partial placental abruption. She is experiencing mild contractions.
Question: What factor is most likely responsible for triggering preterm labor in this patient?
A. Infection and inflammation
B. Decidual hemorrhage with thrombin release
C. Activation of the fetal HPA axis
D. Premature activation of proteases
B. Decidual hemorrhage with thrombin release
Discussion: Partial placental abruption leads to decidual hemorrhage, which results in thrombin release. Thrombin promotes the activation of proteases and prostaglandins, leading to uterine contractions and cervical changes that can trigger preterm labor.
A 27-year-old woman at 31 weeks gestation is admitted with signs of preterm labor. She reports severe emotional stress at home. Examination reveals a slightly dilated cervix but no signs of infection.
Question: Which mechanism is likely contributing to her preterm labor?
A. Premature activation of proteases
B. Uterine overdistension
C. Activation of the maternal HPA axis
D. Decidual hemorrhage
C. Activation of the maternal HPA axis
Discussion: Emotional stress can activate the maternal HPA axis, leading to increased levels of CRH. CRH stimulates prostaglandin production, which can result in uterine contractions and cervical changes, contributing to preterm labor.
A 30-year-old woman at 34 weeks gestation presents with rupture of membranes and is subsequently diagnosed with PROM. She has no contractions at this point.
Question: Which of the following mechanisms is most likely responsible for the PROM?
A. Increased prostaglandin production
B. Increased matrix metalloproteinase (MMP) activity
C. Genetic predisposition
D. Activation of the fetal HPA axis
B. Increased matrix metalloproteinase (MMP) activity
Discussion: PROM is often associated with increased MMP activity, which leads to the breakdown of collagen in the fetal membranes. This weakens the membranes, making them more susceptible to rupture, even in the absence of contractions.
Which of the following is a major maternal complication associated with post-term pregnancy?
A. Oligohydramnios
B. Preterm labor
C. Placenta previa
D. Polyhydramnios
A. Oligohydramnios
Discussion: Oligohydramnios is a common complication in post-term pregnancies due to the decline in placental function. Reduced amniotic fluid volume can lead to cord compression, fetal distress, and complications during labor.
Fetal macrosomia is a risk factor for which of the following complications during labor?
A. Shoulder dystocia
B. Preterm birth
C. Placental abruption
D. Polyhydramnios
A. Shoulder dystocia
Discussion: Fetal macrosomia, or an excessively large baby, increases the risk of shoulder dystocia, where the baby’s shoulder becomes lodged behind the mother’s pubic bone during delivery, making vaginal delivery challenging.
Which of the following perinatal complications is associated with prolonged gestation and reduced placental efficiency?
A. Stillbirth
B. Preterm delivery
C. Polyhydramnios
D. Fetal anemia
A. Stillbirth
Discussion: Prolonged gestation can lead to an aging placenta, which may not adequately deliver nutrients and oxygen to the fetus, increasing the risk of stillbirth.
A post-term pregnancy is more likely to result in which maternal complication due to a larger fetus?
A. Postpartum hemorrhage
B. Preterm labor
C. Placenta previa
D. Polyhydramnios
A. Postpartum hemorrhage
Discussion: A larger fetus increases the risk of uterine overdistension, which can lead to poor uterine contraction (uterine atony) after delivery, resulting in postpartum hemorrhage.
Which condition is characterized by fetal malnutrition, loss of fat, dry skin, and meconium staining in post-term infants?
A. Postmaturity syndrome
B. Preterm syndrome
C. Respiratory distress syndrome
D. Neonatal sepsis
A. Postmaturity syndrome
Discussion: Postmaturity syndrome occurs in post-term infants due to prolonged exposure in the womb and declining placental function. It is characterized by fetal malnutrition, loss of fat, dry or peeling skin, and meconium staining.
A 40-year-old woman at 42 weeks gestation presents for a routine check-up. Ultrasound reveals a decreased amniotic fluid index (AFI) and reduced fetal movement.
Question: What is the primary concern in this post-term pregnancy?
A. Fetal macrosomia
B. Oligohydramnios leading to cord compression
C. Placenta previa
D. Preterm labor
B. Oligohydramnios leading to cord compression
Discussion: In post-term pregnancies, decreased amniotic fluid can lead to oligohydramnios, which increases the risk of cord compression and fetal distress. Close monitoring or intervention may be required.
A 35-year-old pregnant woman at 43 weeks gestation is admitted for labor induction. The estimated fetal weight is 4,200 grams. During labor, the baby’s shoulder becomes lodged after the head is delivered.
Question: Which complication is this patient experiencing?
A. Shoulder dystocia
B. Preterm labor
C. Placental abruption
D. Cord prolapse
A. Shoulder dystocia
Discussion: Shoulder dystocia is a common complication in cases of fetal macrosomia, where the baby’s shoulder gets stuck behind the mother’s pubic bone during delivery, posing risks for both mother and baby.
A 29-year-old woman at 41 weeks gestation is brought to the hospital with decreased fetal movements. On examination, fetal heart tones are absent. Ultrasound confirms intrauterine fetal demise.
Question: What is the most likely cause of this complication in a post-term pregnancy?
A. Placenta previa
B. Stillbirth due to placental insufficiency
C. Preterm labor
D. Uterine rupture
B. Stillbirth due to placental insufficiency
Discussion: In post-term pregnancies, the aging placenta may fail to deliver adequate nutrients and oxygen to the fetus, leading to fetal demise (stillbirth). Close monitoring is essential in late-term pregnancies to prevent such outcomes.
A 33-year-old woman at 42 weeks gestation delivers a baby with peeling skin, decreased fat, and signs of meconium staining. The infant appears thin and is transferred to the NICU for observation.
Question: What condition does this newborn likely have?
A. Postmaturity syndrome
B. Neonatal sepsis
C. Respiratory distress syndrome
D. Hypoxic-ischemic encephalopathy
A. Postmaturity syndrome
Discussion: Postmaturity syndrome occurs in post-term infants who experience malnutrition and decreased fat stores due to prolonged gestation and reduced placental function. The infant often appears thin with peeling skin and may have meconium staining.
A 31-year-old woman at 42 weeks gestation presents in active labor. During delivery, the baby is noted to have a weak cry, poor muscle tone, and requires resuscitation. The history reveals meconium-stained amniotic fluid.
Question: Which perinatal complication is most likely responsible for the newborn’s condition?
A. Meconium aspiration syndrome
B. Neonatal sepsis
C. Preterm birth
D. Placenta previa
A. Meconium aspiration syndrome
Discussion: Meconium aspiration syndrome occurs when the fetus passes meconium into the amniotic fluid, which is then inhaled. This can lead to respiratory distress and poor adaptation at birth, requiring immediate medical intervention.
Which of the following is a common cause of fetal distress due to cord compression?
A. Polyhydramnios
B. Oligohydramnios
C. Placenta previa
D. Fetal anemia
B. Oligohydramnios
Discussion: Oligohydramnios, or low amniotic fluid, reduces the cushioning effect around the umbilical cord, making it more vulnerable to compression during fetal movements or contractions, which can lead to fetal distress.
What is the primary effect of umbilical cord compression on the fetus?
A. Increased nutrient supply
B. Increased fetal heart rate
C. Reduced blood flow and oxygen supply
D. Increased amniotic fluid volume
C. Reduced blood flow and oxygen supply
Discussion: Umbilical cord compression restricts blood flow through the umbilical vein and arteries, reducing the supply of oxygen and nutrients to the fetus and impairing the removal of carbon dioxide, leading to hypoxia and fetal distress.
Which fetal heart rate pattern is commonly associated with umbilical cord compression?
A. Sinusoidal pattern
B. Variable decelerations
C. Early decelerations
D. Accelerations
B. Variable decelerations
Discussion: Variable decelerations are characterized by abrupt drops in fetal heart rate and are commonly associated with umbilical cord compression, indicating transient reductions in blood flow to the fetus.
What physiological response does the fetus exhibit to preserve vital organ function during hypoxia caused by cord compression?
A. Bradycardia
B. Brain-sparing effect
C. Tachycardia
D. Polycythemia
B. Brain-sparing effect
Discussion: During hypoxia, the fetus redistributes blood flow to essential organs such as the brain, heart, and adrenal glands. This compensatory mechanism is known as the “brain-sparing effect” and helps protect these vital organs during periods of reduced oxygen supply.