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OBGYN USMLE Step 3 > Section 4: Obstetrics 4 > Flashcards

Section 4: Obstetrics 4 Flashcards

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USMLE® Step 1 flashcards
1
Q

A 29-year-old primigravida presents to the emergency department at 19 weeks’ gestation with lower pelvic pressure without contractions. She reports increased clear vaginal mucus discharge. Fetal membranes are found to be bulging into the vagina, and the cervix cannot be palpated. Fetal feet can be felt through the membranes. What is the next step in management?

a. Abdominal cerclage
b. Prophylactic antibiotics
c. Tocolysis
d. Vaginal cerclage
e. Rule out chorioamnionitis

A

E. Although emergency cerclage (vaginal or abdominal) is indicated in women who present with cervical dilation in the absence of labor or abruption, it can only be performed when chorioamnionitis is first ruled out. Tocolysis is not appropriate in management of cervical insufficiency. Prophylactic antibiotics and tocolytics are not recommended

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13272-13293). Kaplan Publishing. Kindle Edition.

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2
Q

Indications for methotrexate in abortion

A
  • Pregnancy mass < 3.5 cm diameter
  • Absence of fetal heart motion
  • ß-hCG level < 6,000 mIU
  • No history of folic supplementation
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3
Q

Risk factors for cervical insufficiency

A
  • Second-trimester abortion
  • Cervical laceration during delivery
  • Deep cervical conization
  • Diethylstilbestrol (DES) exposure

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13272-13293). Kaplan Publishing. Kindle Edition.

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4
Q

Rx of cervical insufficiency

A
  • Perform elective cerclage placement at 13– 16 weeks’ gestation for patients with ≥ 3 unexplained midtrimester pregnancy losses
  • Only perform urgent cerclage after first ruling out labor and chorioamnionitis
  • Perform cerclage removal at 36– 37 weeks, after fetal lung maturity

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13293-13308). Kaplan Publishing. Kindle Edition.

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5
Q

What is the next step in management of an asymptomatic woman with no prior history of preterm labor, found to have short cervix on routine transvaginal ultrasound before 16– 20 weeks?

A

Transvaginal ultrasound surveillance to evaluate for persistent cervical shortening, and to evaluate for changes in cervical dilation; however, cerclage is not indicated unless dilation is present and chorioamnionitis or signs of labor are not present. Repeat the exam after 20 weeks if short cervix is still present

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13293-13308). Kaplan Publishing. Kindle Edition.

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6
Q

Intrauterine Growth Restriction (IUGR)

IUGR is the diagnosis when the estimated fetal weight (EFW) is < 5-10 percentile for gestational age or birthweight of < 2,500 g (5 lb, 8 oz).

Accurate, early pregnancy dating is essential for making the diagnosis. An early sonogram (< 20 weeks) is the next step in management if accurate dates are not known.

True or False: Never change the gestational age based on a late sonogram.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13293-13308). Kaplan Publishing. Kindle Edition.

A

True

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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7
Q

List the causes of symmetric IUGR (Fetal causes)

↓ growth potential

A
  1. Aneuploidy
  2. Infection (e.g., TORCH)
  3. Structural anomalies
    • Congenital heart disease,
    • NTD
    • Ventral wall defects

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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8
Q

List the causes of symmetric IUGR (Maternal causes)

↓ placental perfusion

A
  1. Hypertension
  2. Small vessel disease (e.g., SLE)
  3. Malnutrition
  4. Tobacco, alcohol, street drugs

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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9
Q

List the causes of symmetric IUGR (Placental causes)

↓ placental perfusion

A
  • Infarction
  • Abruption
  • Twin-twin transfusion
  • Velamentous cord insertion

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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10
Q

Ultrasound findings in IUGR

  1. Fetal causes
  2. Maternal and placental causes

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

A
  1. ↓ in all measurements
  2. ↓ abdomen measurements; normal head measurements

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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11
Q

List the workup for fetal causes of IUGR

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

A
  • Detailed sonogram
  • Karyotype
  • Screen for fetal infections

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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12
Q

List the workup for maternal and placenta causes of IUGR

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

A
  1. Serial sonograms
  2. Nonstress test
  3. Amniotic fluid index (AFI)
  4. Biophysical profile
  5. Umbilical artery Doppler

AFI is often decreased, especially with severe uteroplacental insufficiency

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13308-13354). Kaplan Publishing. Kindle Edition.

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13
Q

Macrosomia is indicated by a fetus with estimated fetal weight (EFW) > 90– 95 percentile for gestational age or birth weight of 4,000– 4,500 g

List the risk factors for macrosomia

A
  • GDM
  • Overt diabetes
  • Prolonged gestation
  • Obesity
  • ↑ ↑ in pregnancy weight gain
  • Multiparity
  • Male fetus

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13355-13378). Kaplan Publishing. Kindle Edition.

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14
Q

List the complications and management of fetal macrosomia

A

Complications include:

  1. Maternal:
    • Injury during birth
    • Postpartum hemorrhage
    • Emergency cesarean section
  2. Fetus:
    • Shoulder dystocia
    • Birth injury
    • Asphyxia
  3. Neonate:
    • Hypoglycemia
    • Erb palsy

Management: Elective cesarean (if EFW > 4,500 g in diabetic mother or > 5,000 g in nondiabetic mother)

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13355-13378). Kaplan Publishing. Kindle Edition.

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15
Q

Premature Rupture of Membranes (PROM):

This is rupture of the fetal membranes before the onset of labor.

What is the most common risk factor for PROM?

A

Ascending infection from the lower genital tract

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13401-13411). Kaplan Publishing. Kindle Edition.

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16
Q

How is the diagnosis of PROM made?

A
  1. Sterile speculum examination reveals the following:
    • There is posterior fornix pooling of clear amniotic fluid (AF)
    • Fluid is nitrazine positive
    • Fluid is ferning positive
  2. Ultrasound: Oligohydramnios
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17
Q

Criteria for clinically diagnosis of chorioamnionitis

A
  • Maternal fever and uterine tenderness
  • Confirmed PROM
  • Absence of a URI or UTI

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13425-13428). Kaplan Publishing. Kindle Edition.

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18
Q

Outline the management of PROM under the follwing circumstances

  1. Presence of uterine contractions
  2. Presence of chorioamnionitis
  3. Absence of infection before viability (< 24 weeks)
  4. Absence of infection with preterm viability (24-33 weeks)
  5. Absence of infection at term (34 weeks)
A
  1. If uterine contractions are present, do not give tocolysis
  2. If chorioamnionitis is present
    • Get cervical cultures
    • Start IV antibiotics
    • Schedule delivery
  3. Manage patient with bed rest at home
  4. Hospitalize
    • Give IM betamethasone if < 32 weeks
    • Obtain cervical cultures
    • Begin prophylactic ampicillin and erythromycin for 7 days
  5. At term (> 34 weeks): Initiate delivery.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13425-13428).

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19
Q

Obstetric ultrasound

  1. What does the crown–rump length determines?
  2. When is the crown-rump length done
  3. What are the indications for high resolution ultrasonography
A
  1. Determines gestational age
  2. At 10 – 13 weeks
  3. Abnormal maternal serum markers or a family history of congenital malformations

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13355-13378). Kaplan Publishing. Kindle Edition.

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20
Q

Chorionic villous sampling (CVS)

  1. When is CVS perfomed?
  2. Why is it performed
  3. What is the pregnancy loss rate
A
  1. At 12 – 14 weeks
  2. For karyotyping
  3. 0.7%

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13355-13378). Kaplan Publishing. Kindle Edition.

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21
Q

Amniocentesis

When is it perfomed?
 Why is it performed
 What is the pregnancy loss rate
A
  1. After 15 weeks with ultrasound guidance
  2. For karyotyping. AF AFP and acetylcholinesterase from amniotic fluid screens for neural tube defect
  3. 0.5%

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13355-13378). Kaplan Publishing. Kindle Edition.

22
Q

Percutaneous umbilical blood sample

  1. How is it performed?
  2. When is it perfomed?
  3. Why is it performed
  4. What is the pregnancy loss rate
A
  1. Involves ultrasound guided aspiration of fetal blood from the umbilical vein
  2. After 20 weeks’ gestation
  3. Is both diagnostic (e.g., blood gases, karyotype, IgG and IgM antibodies) and therapeutic (e.g., intrauterine transfusion with fetal anemia)
  4. 1– 2 percent

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13379-13405). Kaplan Publishing. Kindle Edition.

23
Q

Fetoscopy

  1. How is it performed?
  2. When is it perfomed?
  3. Why is it performed?
  4. What is the pregnancy loss rate?
A
  1. Transabdominal fiberoptic scope under regional or general anesthesia
  2. After 20 weeks
  3. Indications include intrauterine surgery or fetal skin biopsy (ichthyosis)
  4. 2– 5 percent

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13379-13405). Kaplan Publishing. Kindle Edition.

24
Q

Cervical cerclage

  1. How is it performed?
  2. When is it perfomed?
  3. Why is it performed?
A
  1. Suture encircles the cervix to prevent the cervical canal from dilating
  2. Between 14 and 24 weeks
  3. Indicated electively or emergently in cervical insufficiency

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13379-13405). Kaplan Publishing. Kindle Edition.

25
Q

Describe the features of an adequate uterine contraction (UC)

A
  • Occurs every 2– 3 minutes
  • Lasts 45– 60 seconds
  • Has 50 mm Hg intensity

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13417-13449). Kaplan Publishing. Kindle Edition.

26
Q

Stage 1— Latent phase effacement

  1. Define it
  2. Duration
  3. Features of prolonged latent phase
  4. Most common cause of (3)
  5. Management (3)
A
  1. Begins: Onset of regular UC; Ends: Acceleration of cervical dilatation
  2. < 20 hours (primipara); < 14 hours (multipara)
  3. Prolonged latent phase:
    • Cervix dilated < 3 cm
    • No cervicl change in 20 h (primipara)/14 h (multipara)
  4. Analgesia
  5. Rest and sedation

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13417-13449). Kaplan Publishing. Kindle Edition.

27
Q

Stage 1— Active phase dilation

This stage prepares cervix for dilation

  1. Define it
  2. Duration
  3. Features of active phase prolongation
  4. Features of active phase arrest
  5. Common cause of (3/4)
  6. Management (3/4)
A
  1. Begins: Acceleration of cervical dilation Ends: 10 cm (complete) Rapid cervical dilation
  2. > 1.2 cm/ hour (primipara) or > 1.5 cm/ hour (multipara)
  3. Active phase prolongation:
    • Cervix dilated ≥ 3cm
    • Cervical dilation of < 1.2 cm/ h (primipara) / < 1.5 cm/ h (multipara)
  4. Active phase arrest:
    • Cervix dilated ≥ 3cm
    • No cervical change in ≥ 2h
  5. Causes:
    • Abnormalities with passenger (fetal size or abnormal presentation)
    • Abnormalities with the pelvis or power (dysfunctional contractions)
  6. Management:
    • Hypotonic contractions → IV oxytocin
    • Hypertonic contractions → morphine sedation
    • Adequate contractions → emergency cesarean section

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13442-13502). Kaplan Publishing. Kindle Edition.

28
Q

Stage 2— Descent

  1. Define it
  2. Duration
  3. Features of second stage arrest
  4. Common causes of (3)
  5. Management (3)
A
  1. Begins: 10 cm (complete) Ends: delivery of baby Descent of the fetus
  2. < 2 hours (primipara) or < 1 hour (multipara). Add 1 hour if epidural
  3. Second-stage arrest
    • Failure to deliver within 2 hours (primipara) or 1 hour (multipara)
    • Add additional 1 hour if epidural
  4. Cause: Abnormalities with passenger, pelvis, or power
  5. Management:
    • Fetal head is not engaged → emergency cesarean
    • Fetal head is engaged → trial of obstetric forceps or vacuum extraction

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13442-13502). Kaplan Publishing. Kindle Edition.

29
Q

Stage 3— Expulsion

  1. Define it
  2. Duration
  3. Features of second stage arrest
  4. Common causes of (3)
  5. Management (3)
A
  1. Begins: delivery of baby Ends: delivery of placenta Delivery of placenta
  2. < 30 minutes
  3. Prolonged third stage: Failure to deliver placenta within 30 minutes
  4. Cause: Consider placenta accreta/ increta/ percreta
  5. Management:
    • IV oxytocin
    • If oxytocin fails, attempt manual removal
    • Hysterectomy may be needed

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13442-13502). Kaplan Publishing. Kindle Edition.

30
Q

Umbilical Cord Prolapse (UCP)

An obstetric emergency because a compressed cord has jeopardized fetal oxygenation, cord prolapse most often occurs with rupture of membranes before the head is engaged in breech of transverse lie. A fetal heart rate (FHR) rate that suggests hypoxemia (e.g., severe bradycardia, severe variable accelerations) may be the only clue

Outline the management of UCP

A
  • Never attempt to replace the cord
  • Place the patient in knee-chest position, elevate the presenting part, and give terbutaline to decrease force of contractions
  • Perform immediate cesarean delivery

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13503-13518). Kaplan Publishing. Kindle Edition.

31
Q

Baseline heart rate is the mean FHR during a 10-minute segment of time, excluding periodic changes.

List the common causes of changes in fetal heart rate

A
  • Uterine hyperstimulation (commonly caused by medications)
  • Fetal head compression
  • Umbilical cord compression
  • Placental insufficiency

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13503-13518). Kaplan Publishing. Kindle Edition.

32
Q

Define

  1. Normal baseline FHR
  2. Tachycardia
  3. Bradycardia
A
  1. 110– 160 beats/ minute
  2. > 160 beats/ minute is most commonly related to medications (β-agonist: terbutaline, ritodrine)
  3. < 110 beats/ minute is most commonly related to medications (β-blockers or local anesthetics)
  5. . Reassuring FHR tracing: • Baseline FHR 110– 160 beats/ minute • (+) Accelerations • (-) Decelerations • (+) Beat-to-beat variability Nonreassuring FHR tracing: • Baseline FHR shows tachycardia or bradycardia • (–) Accelerations • (+) Variable or late decelerations • (–) Beat-to-beat variability Periodic changes in heart rate include the following: Accelerations: Abrupt increases in FHR lasting < 2 minutes that are unrelated to contractions. They always occur in

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13519-13536). Kaplan Publishing. Kindle Edition.

33
Q

Features of reassuring fetal heart tracing

A
  • Baseline FHR 110 – 160 beats/ minute
  • (+) Accelerations
  • (-) Decelerations
  • (+) Beat-to-beat variability
  • Nonreassuring FHR tracing: • Baseline FHR shows tachycardia or bradycardia • (–) Accelerations • (+) Variable or late decelerations • (–) Beat-to-beat variability Periodic changes in heart rate include the following: Accelerations: Abrupt increases in FHR lasting < 2 minutes that are unrelated to contractions. They always occur in

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13519-13536). Kaplan Publishing. Kindle Edition.

34
Q

Features of non-reassuring fetal heart tracing

A
  • Baseline FHR shows tachycardia or bradycardia
  • (–) Accelerations
  • (+) Variable or late decelerations
  • (–) Beat-to-beat variability

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13519-13536). Kaplan Publishing. Kindle Edition.

35
Q

Spot diagnosis

What does this indicate?

A

Early decelerations.

Indicates head compression

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13519-13536). Kaplan Publishing. Kindle Edition.

36
Q

Spot diagnosis

What does this indicate?

A

Variable decelerations

Indicates umbilical cord compression

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13536-13542). Kaplan Publishing. Kindle Edition.

37
Q

Spot diagnosis

What does this indicate?

A

Late decelerations

Uteroplacental insufficiency

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13536-13542). Kaplan Publishing. Kindle Edition.

38
Q

List and describe the periodic changes in fetal heart rate

A

Accelerations: Abrupt increases in FHR lasting < 2 minutes that are unrelated to contractions. They always occur in response to fetal movements and are always reassuring.

Early decelerations: Gradual decreases in FHR beginning and ending simultaneously with contractions. They occur in response to fetal head compression.

Variable decelerations: Abrupt decreases in FHR that are unrelated to contractions. These are related to umbilical cord compression. Severe variables are nonreassuring and indicate fetal acidosis.

Late decelerations are gradual decreases in FHR and delayed in relation to contractions. These are related to uteroplacental insufficiency. All late decelerations are nonreassuring and indicate fetal acidosis.

Variability: Beat-to-beat fetal heart rate normally has variability. Normal variability is 6– 25 beats/ minute. Absence of variability is a nonreassuring pattern.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13543-13548). Kaplan Publishing. Kindle Edition.

39
Q

List the non-reassuring changes in fetal heart rate patterns

A
  • Variable decelerations
  • Late decelerations
  • Absence of beat-to-beat variability

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13543-13548). Kaplan Publishing. Kindle Edition.

40
Q

A 31-year-old primigravida at term is in the maternity unit in active labor. She is 6 cm dilated, 100 percent effaced 0 station, with the fetus in cephalad position. IV oxytocin is being administered because of arrest of cervical dilation at 6 cm. Fetal membranes are intact. The nurse informs you that the external fetal monitor tracing now shows the fetal heart rate baseline at 175/ minute with minimal variability and repetitive late decelerations. There is no vaginal bleeding. What is the most appropriate next step in management?

a. Change maternal position
b. Discontinue oxytocin
c. Immediate cesarean section
d. Perform obstetric ultrasound
e. Obtain fetal scalp pH

A

B. Medications are a common cause of baseline fetal tachycardia or bradycardia

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13549-13573). Kaplan Publishing. Kindle Edition.

41
Q

Outline the stepwise approach to non-reassuring fetal tracings

A
  1. Examine the electronic fetal monitoring (EFM) strip: Look for non-reassuring patterns
  2. Identify nonhypoxic causes that can explain the abnormal findings. (Most common are medications, particularly β-agonists or β-blockers.)
  3. Begin intrauterine resuscitation as follows:
    • Discontinue medications (e.g., oxytocin)
    • Give IV normal saline bolus
    • Provide high-flow oxygen
    • Change patient’s position (left lateral)
    • Vaginal exam to rule out prolapsed cord
    • Perform scalp stimulation to observe for accelerations (reassuring)
  4. Prepare for delivery if the EFM tracing does not normalize
  5. If the EFM is unequivocal, obtain fetal scalp pH (requires dilated cervix and ruptured membranes). Normal fetal pH > 7.20

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13549-13573). Kaplan Publishing. Kindle Edition.

42
Q

Indications for Forceps- or Vacuum-Assisted Delivery

A
  • Prolonged second stage (most common indication)
  • Nonreassuring EFM strip in absence of contraindications
  • To avoid maternal pushing when mother has cardiac and/ or pulmonary conditions that would increase her risk

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13574-13587). Kaplan Publishing. Kindle Edition.

43
Q

Contraindications to Forceps- or Vacuum-Assisted Delivery

A
  • Mother has small pelvis
  • Cervix is not fully dilated
  • Membranes have not ruptured
  • Fetal head is not engaged
  • Orientation of the head is not certain

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13574-13587). Kaplan Publishing. Kindle Edition.

44
Q

The cesarean section rate is approximately 33 percent in the United States (including both primary and repeat procedures).

Risks include the following: Increased risk of hemorrhage, infection, visceral injury (bladder, bowel, ureters), and DVTs.

Low segment transverse incision: This is the most common procedure. It can only be performed with longitudinal lie of the fetus.

Classic vertical incision: Can be performed with any fetal lie. Because of the increased risk of uterine rupture in subsequent pregnancies, cesarean must be initiated before labor begins.

Indications for CS

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13574-13587). Kaplan Publishing. Kindle Edition.

A

Cephalopelvic disproportion (CPD): With failure of progression or arrest in labor

Fetal malpresentation: Most commonly preterm breech and nonfrank breech

Nonreassuring EFM strip

Placenta previa (unless placental edge > 2 cm from internal os)

Infection: Mother who is HIV-positive or has active vaginal herpes

Uterine scar: Prior myomectomy (fibroid) or prior classic incision c-section

Trial of vaginal birth after cesarean (VBAC) should be attempted in patients in the absence of c-section indications when the previous cesarean was a low segment uterine incision. The success rate is 80 percent.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13587-13600). Kaplan Publishing. Kindle Edition.

45
Q

External cephalic version (ECV)

  1. Indications
  2. Optimal time
  3. Success rate
A
  1. Transverse lie or breech presentation
  2. 37 weeks’ gestation
  3. 60– 70 percent

External cephalic version (ECV) is done to change a baby from breech or other non-cephalic presentation to the cephalic position. The physician pushes on the baby through the mother’s abdomen to attempt to roll the baby into position

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13600-13616). Kaplan Publishing. Kindle Edition.

46
Q

List the causes of post-partum hemorrhage

A
  • Uterine atony (most common cause of excessive postpartum bleeding)
  • Lacerations
  • Retained placenta
  • DIC
  • Uterine inversion
  • Urinary retention

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13600-13616). Kaplan Publishing. Kindle Edition.

47
Q

Causes of DIC in pregnancy/labor/delivery

Management of retained placenta

A

DIC (Suspect DIC when there is generalized oozing or bleeding from IV or laceration sites in the presence of a contracted uterus)

  • Abruptio placenta
  • Severe preeclampsia
  • Amniotic fluid embolism
  • Prolonged retention of a dead fetus

Management of retained placenta

  • Manual removal
  • Uterine curretage under ultrasound guidance
  • Hysterectomy may be indicated

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13616-13628). Kaplan Publishing. Kindle Edition.

48
Q

Presentation and management of Uterine inversion

Rx of urinary retention

A

Uterine inversion:

  • Beefy-appearing bleeding mass in the vagina
  • Failure to palpate the uterus
  • Management involves uterine replacement, followed by IV oxytocin.

Urinary retention may occur with a hypotonic bladder.

  • If residual volume is > 250 mL, give bethanechol (Urecholine)
  • If this fails, urinary catheterize for no more than 2– 3 days

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13616-13628). Kaplan Publishing. Kindle Edition.

49
Q

Special notes on Postpartum Contraception in:

Breastfeeding

Diaphrag and IUD placement

Combined estrogen-progestin formulations

Progestin contraception

A

Breastfeeding:

  • Contraceptive use may be deferred for 3 months in women who are breastfeeding because of temporary anovulation

Diaphragm and IUD placement:

  • Deferred until the 6- week postpartum visit

Combined estrogen-progestin formulations (e.g., pills, patch, vaginal ring):

  • Not started until 3 weeks postpartum to prevent hypercoagulable state and risk of DVT
  • They are not used in breastfeeding women because of diminished lactation.

Progestin contraception (e.g., mini-pill, Depo-Provera, Implanon):

  • Can safely be used during breastfeeding
  • They can be begun immediately after delivery.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 13629-13678). Kaplan Publishing. Kindle Edition.

50
Q

Based on the post-partum days list the diagnosis, risk factors, clinical findings and management of the different causes of PP fever.

Day 0

Day 1

day 2-3

Day 4-5

Day 5-6

Day 7-21

A

See table for answers

OBGYN USMLE Step 3 (7 decks)

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