Section 2: Obstetrics 2

Question 1

A 28-year-old woman in her 28th week of pregnancy presents for severe lower back pain. She complains that the pain is cyclical and that it seems to be increasing in intensity. On physical examination, she seems to be in pain. Her temperature is 98.9°F, HR 104 bpm, BP 135/80 mm Hg, RR 15 per minute. On pelvic examination, her cervix is 3 cm dilated. Which of the following is the most likely diagnosis?

a. Premature rupture of membranes
b. Preterm labor
c. Cervical incompetence
d. Preterm contractions

Fischer, Conrad (2012-11-01). Master the Boards USMLE Step 2 CK (Page 452). Kaplan Medical Test Prep. Kindle Edition.

Answer 1

B. Preterm labor is diagnosed when there is a combination of contractions with cervical dilation. A premature rupture of membranes patient would have a history of a “gush of fluid” from the vagina. Patients with cervical incompetence do not have a history of contractions, but there is painless dilation of the cervix. Preterm contractions do not lead to cervical dilation.

Fischer, Conrad (2012-11-01). Master the Boards USMLE Step 2 CK (Page 452). Kaplan Medical Test Prep. Kindle Edition.

Question 2

List the risk factors for preterm labor

Answer 2

1. Premature rupture of membranes
2. Multiple gestation
3. Previous history of preterm labor
4. Placental abruption
5. Maternal factors
   
   • Uterine anatomical abnormalities
   • Infections (chorioamnionitis)
   • Preeclampsia
   • Intraadominal surgery

Fischer, Conrad (2012-11-01). Master the Boards USMLE Step 2 CK (Page 452). Kaplan Medical Test Prep. Kindle Edition.

Question 3

List the circumstances under which preterm labor should not be stopped with tocolytics and delivery should occur

Answer 3

• Maternal severe HTN (preeclampsia)
• Maternal cardiac disease
• Maternal cervical dilation of more than 4 cm
• Maternal hemorrhage (abruptio placenta, DIC)
• Fetal death
• Chorioamnionitis

Question 4

List the causes of late pregnancy bleeding (i.e., bleeding that occurs after 20 weeks’ gestation)

Answer 4

• Abruptio placenta (painful)
• Placenta previa (painless)
• Vasa previa (painless)
• Less commonly, lower genital tract lacerations and uterine rupture
• bleeding: • Perform initial management: – Get the patient’s vitals

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12464-12480). Kaplan Publishing. Kindle Edition.

Question 5

List the initial steps in the management of late pregnancy bleeding

Answer 5

1. Perform initial management:
   
   • Get the patient’s vitals
   • Place external fetal monitor
   • Start IV fluids with normal saline
2. Order lab tests:
   
   • CBC
   • DIC workup (platelets, PT, PTT, fibrinogen, and D-dimer)
   • Type and cross-match
   • Obstetric ultrasound to rule out placenta previa
3. Perform further steps in management:
   
   • Give blood transfusion for large volume loss
   • Place Foley catheter and measure urine output
   • Perform vaginal exam to rule out lacerations
   • Schedule delivery if fetus is in jeopardy or gestational age is ≥ 36 weeks

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12477-12499). Kaplan Publishing. Kindle Edition.

Question 6

True or False: Never perform a digital or speculum examination in a patient with late vaginal bleeding until a vaginal ultrasound first rules out placenta previa

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12477-12499). Kaplan Publishing. Kindle Edition.

Answer 6

True

Question 7

How do we know there is compromise in late pregnancy bleeding?

What condition most likely causes this and why?

Answer 7

Late decelerations and/or bradycardia

Vasa previa because the bleeding is from fetal circulation

Question 8

List (1) diagnosis, (2) diagnostic test, (3) management and (4) complication based on the following presentation

• Sudden onset vaginal bleeding
• Pain
• Hx of HTN
• +/- Trauma
• +/- Cocaine abuse

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12502-12522). Kaplan Publishing. Kindle Edition.

Answer 8

1. Abruptio placenta
2. Abd/Pelvic US
3. Mgnt:
   
   • Emergent c-section
   • Vaginal delivery may be attempted if ≥ 36 weeks and placenta is > 2 cm from internal os
   • Admit and observe if bleeding has stopped, vitals and fetal heart rate (FHR) stable, or < 34 weeks
4. DIC. Amniotomy and induction of labor decrease the risk of DIC

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12587-12590). Kaplan Publishing. Kindle Edition.

Question 9

List (1) diagnosis, (2) diagnostic test, (3) management and (4) complication based on the following presentation

• Sudden onset vaginal bleeding at rest or during activity without warning
• No pain
• +/- Trauma, coitis, or pelvic examination
• +/- Multiparity
• +/- Structural abnormalities (e.g. fibroids)
• Advanced maternal age

Answer 9

1. Placenta previa. Occurs when the placenta is implanted in the lower uterine segment. As the lower uterus stretches, placental villi dislodge and painless vaginal bleeding results
2. Abd/pelvic US
3. Mgnt:
   
   • Emergent c-section if patient/ fetus is deteriorating
   • Vaginal delivery if ≥ 36 weeks or continued bleeding
   • Admit and observe if bleeding has stopped, vitals and fetal heart rate (FHR) stable, or < 34 weeks
4. Placenta accreta/increata/percreta → hysterectomy

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12502-12522). Kaplan Publishing. Kindle Edition.

Question 10

List (1) diagnosis, (2) diagnostic test, (3) management and (4) complication based on the following presentation

• Rupture of membranes
• Painless vaginal bleeding
• Fetal bradycardia

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12523-12544). Kaplan Publishing. Kindle Edition.

Answer 10

1. Vasa Previa
2. Abd/pelvic US
3. Emergency CS
4. Fetal exsanguination

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12523-12544). Kaplan Publishing. Kindle Edition.

Question 11

List (1) diagnosis, (2) diagnostic test, (3) management and (4) complication based on the following presentation

• Hx of uterine scar
• Sudden onset abd pain
• Sudden vaginal bleeding
• Loss of electronic fetal heart rate
• Loss of electronic uterine contractions
• Recession of the fetal head
• +/- Myomectomy for fibroids
• +/- Excessive oxytocin
• +/- Grand multiparity

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12523-12544). Kaplan Publishing. Kindle Edition.

Answer 11

1. Uterine rupture
2. N/A
3. Immediate surgery and delivery
4. Hysterectomy for uncontrolled bleeding

Question 12

A 28-year-old woman presents at 36 weeks’ gestation with rupture of membranes. On examination she is found to have 7 cm cervical dilatation. She received all of her prenatal care, and her only complication was a course of antibiotics for asymptomatic bacteriuria. GBS screening was negative. Her first baby was hospitalized for 10 days after delivery for GBS pneumonia and sepsis. What is the most appropriate management?

a. Administer intrapartum IV penicillin
b. Administer intramuscular azithromycin
c. Rescreen for group B streptococci
d. Schedule cesarean section
e. No intervention is needed

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12602-12613). Kaplan Publishing. Kindle Edition.

Answer 12

A. Intrapartum IV penicillin is indicated because the patient’s previous birth was complicated with neonatal GBS sepsis.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12602-12613). Kaplan Publishing. Kindle Edition.

Question 13

True or False:

1. Thirty percent of women have asymptomatic vaginal colonization with GBS
2. Vertical transmission results in pneumonia and sepsis in the neonate within hours to days of birth
3. There is a 50 percent mortality rate with neonatal infection
4. GBS-related meningitis occurs after the first week and is a hospital-acquired infection that is related to vertical transmission

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Answer 13

1. True
2. True
3. True
4. False. The infection is unrelated to vertical transmission

Question 14

List the Rx of GBS

Answer 14

• Intrapartum IV penicillin G
• Penicillin allergy: IV cefazolin, clindamycin, or erythromycin

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Question 15

Indications for Rx of GBS

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Answer 15

1. GBS (+) urine, cervical, or vaginal culture at any time during pregnancy
2. Presence of high-risk factors:
   
   • Preterm delivery
   • Membrane rupture > 18 hours
   • Maternal fever
   • Previous baby with GBS sepsis

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Question 16

Exceptions to antibiotic use in GBS

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12634-12654). Kaplan Publishing. Kindle Edition.

Answer 16

• Planned c-section without rupture of membranes (even if culture is [+])
• Culture (+) on a previous pregnancy, but culture (–) in the current pregnancy

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12634-12654). Kaplan Publishing. Kindle Edition.

Question 17

Interpret the following results:

1. IgG antibodies to GBS in the mother
2. IgM antibodies to GBS in the mother

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Answer 17

1. Past exposure and are protective
2. Suggests recent exposure and risk of exposure to the fetus.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12613-12632). Kaplan Publishing. Kindle Edition.

Question 18

Toxoplasmosis in the infant:

1. Causative organism
2. Risk factors (RF)
3. Prevention
4. Rx

Answer 18

1. Toxoplasma gondii
2. RF:
   
   • Patient handling cat feces or litter boxes
   • Drinking raw goat milk
   • Eating raw meat.
3. Prevention: Avoid risk factors
4. Pyrimethamine and sulfadiazine

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12634-12654). Kaplan Publishing. Kindle Edition.

Question 19

Diagnosis:

1. Chorioretinitis
2. Intracranial calcifications
3. Hydrocephalus

Answer 19

Congenital toxoplasmosis

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12634-12654). Kaplan Publishing. Kindle Edition.

Question 20

A 29-year-old woman (G2 P1) is at 34 weeks’ gestation. She complains of uterine contractions every 5 minutes. Her previous records are not available. During the last few days, she has developed diffuse pruritic vesicles on her neck, which appear to be also developing on her chest and breasts. She has a fever and complains of malaise. Which of the following is the next step in management?

a. Oral acyclovir
b. RhoGAM
c. Varicella zoster antibody assay
d. Varicella vaccine
e. Varicella zoster immunoglobulin

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12661-12673). Kaplan Publishing. Kindle Edition.

Answer 20

C. Varicella antibodies are seen in 90 percent of pregnant women due to prior infection. Varicella antibodies are protective, and no therapy is necessary

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12661-12673). Kaplan Publishing. Kindle Edition.

Question 21

1. Diagnosis:

• Zigzag” skin lesions
• Limb hypoplasia
• Microcephaly
• Microphthalmia
• Chorioretinitis
• Cataracts.

2. Prevention of above
3. Rx of above

Answer 21

1. Neonatal varicella infection. Transplacental infection results from primary varicella infection in the mother (25– 40 percent infection rate). The greatest risk to the fetus is if a rash appears in the mother between 5 days antepartum and 2 days postpartum.
2. Prevention
   
   • Vaccination: Live-attenuated varicella virus (Varivax III) to nonpregnant women
   • Postexposure prophylaxis: VariZIG (antivaricella antibodies) or varicella zoster immunoglobulin within 96 hours of exposure. VariZIG/ VZIG does not prevent infection but only attenuates the clinical effects of the virus.
3. Treatment
   
   • Maternal varicella: VariZIG to mother and neonate
   • Congenital varicella: VariZIG and IV acyclovir to the neonate

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12674-12691). Kaplan Publishing. Kindle Edition.

Question 22

Diagnosis:

• Congenital deafness (most common sequelae)
• Ccongenital heart disease (e.g., patent ductus arteriosus, or PDA)
• Cataracts
• Mental retardation
• Hhepatosplenomegaly
• Tthrombocytopenia
• “Blueberry muffin” rash

Prevention?

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12674-12691). Kaplan Publishing. Kindle Edition.

Answer 22

Diagnosis: Congenital rubella

Prevetion:

• Perform first-trimester screening and have mother avoid infected individuals
• Immunize seronegative women after delivery
• No postexposure prophylaxis is available

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12692-12713). Kaplan Publishing. Kindle Edition.

Question 23

A 24-year-old child-care worker is 29 weeks pregnant and is currently working. One of the children was diagnosed with rubella last week. Rubella antigen testing is performed and her IgG titer is negative. What is the risk of neonatal transmission in this patient? What is the next step in management?

a. Give anti-rubella antibodies
b. Give betamethasone
c. Give rubella vaccine now
d. Give rubella vaccine after delivery
e. Ultrasound of the fetus

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12692-12713). Kaplan Publishing. Kindle Edition.

Answer 23

D. There is no postexposure prophylaxis available, and immunization during pregnancy is contraindicated (live vaccine). The only correct management is to await normal delivery and give vaccination to the mother after delivery

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12692-12713). Kaplan Publishing. Kindle Edition.

Question 24

Diagnosis:

• Most common congenital viral syndrome in the United States
• Most common cause of sensorineural deafness in children
• Spread by infected body fluid secretions
• The greatest risk for vertical transmission occurs with primary infection (infection rate is 50 percent)
• Most mothers develop asymptomatic infections or describe mild, mononucleosis-like symptoms.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12692-12713). Kaplan Publishing. Kindle Edition.

Answer 24

Cytomegalovirus (CMV)/Congenital CMV

About 10% of infants with congenital CMV infection are symptomatic at birth

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12692-12713). Kaplan Publishing. Kindle Edition.

Question 25

Diagnosis: * Intrauterine growth restriction (IUGR) * Prematurity * Microcephaly * Jjaundice * Petechiae * Hepatosplenomegaly * Periventricular calcifications * Chorioretinitis * Pneumonitis

Answer 25

Congenital CMV Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12713-12729). Kaplan Publishing. Kindle Edition.

Question 26

Interpretation of results: 1. Maternal IgG (+) / IgM (–) 2. Maternal IgG (+) / IgM (+) 3. Maternal IgG (–) / IgM (+) indicates recent infection.

Answer 26

1. Indicates past exposure and no risk for primary infection 2. Indicates recent infection 3. Indicates recent infection Perform a viral culture from urine or other body fluids in first 2 weeks of life and CMV DNA-PCR Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12713-12729). Kaplan Publishing. Kindle Edition.

Question 27

1. Prevention of CMV 2. Rx of CMV

Answer 27

1. Prevention: * Follow universal precautions with all body fluids. * Avoid transfusion with CMV-positive blood 2. Treatment: * Antiviral therapy with **ganciclovir**. This prevents viral shedding and prevents hearing loss but does not cure the infection Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12713-12729). Kaplan Publishing. Kindle Edition.

Question 28

A 21-year-old multipara is admitted to the birthing unit at 39 weeks gestation in active labor at 6 cm dilation. Membranes are intact. She has a history of genital herpes preceding the pregnancy. Her last outbreak was 8 weeks ago. She now complains of pain and pruritus. On examination, she had localized, painful, ulcerative lesions on her right vaginal wall. Which of the following is the next step in management? a. Administer IV acyclovir b. Administer terbutaline c. Obtain culture of ulcer d. Proceed with vaginal delivery e. Schedule cesarean section Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12729-12748). Kaplan Publishing. Kindle Edition.

Answer 28

**E**. Active genital herpes is an indication for cesarean section. The only other infection-related indication for cesarean section is HIV sero-positive status of the mother Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12729-12748). Kaplan Publishing. Kindle Edition.

Question 29

True or False: 1. The most common cause of transmission is contact with maternal genital lesions during an active HSV episode. 2. Transplacental infection can also occur with primary infections during pregnancy (50 percent risk). 3. Greatest risk is primary infection in the third trimester. 4. Neonatal infection acquired during delivery has 50 percent mortality rate. 5. Surviving infants develop meningoencephalitis, mental retardation, pneumonia, hepatosplenomegaly, jaundice, and petechiae. Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12729-12748). Kaplan Publishing. Kindle Edition.

Answer 29

1. True 2. True 3. True 4. True 5. True Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12729-12748). Kaplan Publishing. Kindle Edition.

Question 30

Diagnostic test for HSV Rx of HSV

Answer 30

Diagnostic Testing (+) HSV culture from vesicle fluid or ulcer or HSV PCR of maternal blood (not screened routinely) Rx: Acyclovir Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12729-12748). Kaplan Publishing. Kindle Edition.

Question 31

Prevention of HSV

Answer 31

* Perform **c-section** in women with lesions suspicious for active genital HSV at the time of labor * Do not use fetal scalp electrodes for monitoring (increased risk of HSV transmission) * Manage expectantly for premature rupture of membranes (PROM) or prolonged rupture of membranes (ROM) (i.e., \> 8–12 hours) * Advise standard precautions (avoid intercourse if partner has active lesions, avoid oral sex in presence of oral lesions, avoid kissing neonate in presence of oral lesions) Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12749-12766). Kaplan Publishing. Kindle Edition.

Question 32

A 24-year-old HIV positive female (G2 P1) presents in her 16th week of pregnancy. Her previous child was diagnosed HIV positive after vaginal delivery. What is the most effective method of decreasing the risk of vertical transmission? a. Avoidance of artificial rupture of membranes b. Avoidance of breastfeeding c. Antiretroviral triple therapy d. Cesarean section e. Zidovudine monotherapy Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12749-12766). Kaplan Publishing. Kindle Edition.

Answer 32

**C**. All of the strategies are recommended, however. Zidovudine (ZDV) monotherapy is not as effective as triple therapy in decreasing the risk of HIV transmission to the fetus (25 percent to 8 percent). **Triple antiretroviral therapy is indicated for more effective management of HIV in the mother to drive the viral load to \< 1,000**. ZDV monotherapy alone is never indicated. Cesarean section (before rupture of membranes), avoidance of breastfeeding or intrapartum invasive procedures (artificial ROM, fetal scalp electrodes) also decreases transmission rate. Combination of all of the above strategies listed above reduces the transmission rate to 1 percent. Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12749-12766). Kaplan Publishing. Kindle Edition.

Question 33

**HIV** 1. True or False: Major route of vertical transmission is contact with infected genital secretions at the time of vaginal delivery 2. What is the vertical transmission rate without Rx 3. True or False: . Elective cesarean is of most benefit in women with low CD4 counts and high RNA viral loads (\> 1,000) 4. True or False: All neonates of HIV-positive women will have positive HIV tests from transplacental passive IgG passage 5. True or False: Zidovudine monotherapy is no longer indicated for anyone 6. Continue antiretrovirals in pregnancy for HIV (+) patients with low CD4 counts and/ or high viral load.

Answer 33

1. True 2. 25– 30 percent 3. True 4. True 5. True 6. True Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12766-12786). Kaplan Publishing. Kindle Edition.

Question 34

Outline Prevention and Rx of HIV in pregnancy

Answer 34

1. Triple-drug therapy (which must include ZDV): * **Starting at 14 weeks** for mothers who have high CD4 counts and do not need medication for their own health and continuing throughout pregnancy * Intravenous intrapartum ZDV * **Combination ZDV-based ART for 6 weeks after delivery** 2. Give the infant prophylaxis against pneumocystis pneumonia (trimethoprim-sulfamethoxazole) and continue for 6 weeks after AZT therapy has been completed 3. Schedule C-section at 38 weeks unless \< 1,000 viral copies/mL 4. Advise the mother not to breastfeed 5. Avoid invasive procedures (e.g., artificial rupture of membranes, fetal scalp electrodes). **HIV-infected pregnant women should receive ART therapy regardless of HIV RNA level** **Do a c-section of the mother’s viral load is \> 1,000 at the time of delivery.** Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12766-12786). Kaplan Publishing. Kindle Edition.

Question 35

1. True or False: Prior syphilis infection confers immunity 2. True or False: Transplacental infection results from primary and secondary infection (60 percent risk of transmission) 3. True or False: The lowest risk of transmission is with latent or tertiary infection.

Answer 35

1. False 2. True 3. True Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12789-12804). Kaplan Publishing. Kindle Edition.

Question 36

List the symptoms/outcomes of early acquired (first trimester) congenital syphilis

Answer 36

* Nonimmune hydrops fetalis * Maculopapular or vesicular peripheral rash * Anemia, thrombocytopenia, and hepatosplenomegaly * Large and edematous placenta * Perinatal mortality rates ~ 50 percent Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12789-12804). Kaplan Publishing. Kindle Edition.

Question 37

List the symptoms/outcomes of late acquired congenital syphilis

Answer 37

Hutchinson teeth “Mulberry” molars “Saddle” nose “Saber” shins Deafness (cranial nerve 8 palsy) Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12789-12804). Kaplan Publishing. Kindle Edition.

Question 38

1. True or False: C-section will not prevent vertical transmission of syphilis, because it happens through the placenta before birth 2. True or False: Always order an HIV test in any pregnant patient who has tested positive for an STD Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12804-12820). Kaplan Publishing. Kindle Edition.

Answer 38

1. True 2. True

Question 39

Diagnosis and Rx of syphilis in pregnancy

Answer 39

Diagnostic Testing * VDRT or RPR screening in first trimester. Confirm (+) screen with FTA-ABS or MHA-TP * Screening test will be falsely negative in primary syphilis. – When the case describes a woman with a painless genital ulcer, order darkfield microscopy for diagnosis of primary syphilis Treatment * Benzathine penicillin IM × 1 for (+) mothers * Penicillin allergy: **Oral desensitization followed by full dose benzathine penicillin** Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12804-12820). Kaplan Publishing. Kindle Edition.

Question 40

A 34-year-old multigravida presents for prenatal care in the second trimester. She admits to a past history of substance abuse but states she has been clean for 6 months. With her second pregnancy, she experienced a preterm delivery at 34 weeks’ gestation of a male neonate who died within the first day of life. She states that at delivery, the baby was swollen with skin lesions and that the placenta was very large. She was treated with antibiotics, but she does not remember their name or other details. On a routine prenatal panel with this current pregnancy, she is found to have a positive VDRL test. What is the next step in management? a. FTA-ABS b. Intramuscular penicillin c. Lupus anticoagulant d. Oral penicillin e. RPR f. Ultrasound Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12804-12820). Kaplan Publishing. Kindle Edition.

Answer 40

**A**. The next step after any positive screening test is the confirmatory test before starting therapy. FTA-ABS or MHA-TP are the confirmatory tests for syphilis. Once syphilis is confirmed, the most appropriate management is intramuscular penicillin Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12804-12820). Kaplan Publishing. Kindle Edition

Question 41

1. Ways of acquisition of neonatal hepatitis B virus (HBV) infection 2. How many percent of neonates who get infected develop chronic hepatitis

Answer 41

1. Neonatal HBV: * In the third trimester * Ingestion of infected genital secretions **during vaginal delivery** 2. 80 percent compared with only 10 percent of infected adults. Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12821-12846). Kaplan Publishing. Kindle Edition.

Question 42

A 29-year-old multigravida was found on routine prenatal laboratory testing to be positive for hepatitis B surface antigen. She is an intensive care unit nurse. She received 2 units of packed red blood cells 2 years ago after experiencing postpartum hemorrhage with her last pregnancy. Which of the following indicates the greatest risk of transmission? a. Anti-HBc b. Anti-HBs c. HBe Ag d. HBs Ag e. IgM anti-HBc Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12821-12846). Kaplan Publishing. Kindle Edition.

Answer 42

**C**. Mothers who are (+) for HBsAg, anti-HBc, and IgM anti-HBc are acutely infected. There is only a 10 percent vertical transmission risk. Mothers who are also **(+) for HBeAg** have an **80 percent risk** of transmission to fetus. Anti-HBs (antibody to surface antigen) indicates immunity to infection from previous immunization. Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12821-12846). Kaplan Publishing. Kindle Edition.

Question 43

Prevention of HBV infection in the neonate

Answer 43

1. Hepatitis B infection is not an indication for cesarean delivery. 2. Avoid invasive procedures during pregnancy (e.g., amniocentesis) 3. Breastfeeding is not contraindicated after the neonate has received active immunization and HBIG 4. Immunization: * **HBsAg-negative**: Give active immunization during pregnancy * **Postexposure prophylaxis for the mother**: HBIG (antibodies to hepatitis B) passive immunization 5. Treatment: * **Hepatitis immunization and HBIG in neonate** * Chronic HBV can be treated with either **interferon or lamivudine** Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12846-12866). Kaplan Publishing. Kindle Edition.

Question 44

List the contraindications to breastfeeding

Answer 44

1. Infections in the mother: * HIV * Active tuberculosis * HTLV-1 * Herpes simplex if there is a lesion on the breast 2. Use of drugs/ medications 3. Drugs of abuse (except cigarettes, alcohol) 4. Cytotoxic medications (e.g., methotrexate, cyclosporine) 5. Condition of the infant – **Galactosemia** Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 12850-12860). Kaplan Publishing. Kindle Edition.