USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 591:

  A22-year-old G3P1102 is admitted to the Labor and Delivery ward at 28 weeks' gestation complaining of watery vaginal discharge. You confirm the diagnosis of preterm premature rupture of amniotic membranes (PPROM). Fetal monitoring demonstrates reassuring fetal heart tones and no contractions are noted. The patient is understandably concerned and asks you why this happened and what this means for her pregnancy. Which of the following should you tell her? Which of the following is the most appropriate therapy for this woman?

  A. begin antibiotic therapy to prolong the latency period until labor begins

  B. immediate cesarean delivery to prevent umbilical cord prolapse

  C. induction of labor to prevent intraamniotic infection

  D. amniocentesis to determine fetal lung maturity status

  E. placement of a cervical cerclage to prevent preterm delivery

  Correct Answer: A

  Multiple randomized-controlled trials have now demonstrated the benefit of administering antibiotics to women with PPROM at less than 32 weeks' gestation. Most importantly, these drugs prolong the latent period until labor begins, but reductions have also been noted inmaternal infection, fetal infection, fetal respiratory distress syndrome, and fetal intraventricular hemorrhage. Commonly used antibiotics are ampicillin and erythromycin, but efficacy has been noted with many different regimens. Cesarean delivery at this point is not indicated, but might need to be performed in case of nonreassuring fetal status or malpresentation (e.g., breech). Induction of labor generally takes place between 32 and 34 weeks if the patient's status remains stable, or sooner in the event of amniotic infection or other concerns. Amniocentesis may be performed to look for evidence of amniotic infection, but the likelihood of fetal lung maturity at this point is remote. Patients with previously placed cervical cerclages may be candidates for expectant management with the cerclage in place, but it would be inappropriate to place a cerclage after PPROM.

• Question 592:

  A22-year-old G3P1102 is admitted to the Labor and Delivery ward at 28 weeks' gestation complaining of watery vaginal discharge. You confirm the diagnosis of preterm premature rupture of amniotic membranes (PPROM). Fetal monitoring demonstrates reassuring fetal heart tones and no contractions are noted. The patient is understandably concerned and asks you why this happened and what this means for her pregnancy. Which of the following should you tell her?

  A. The incidence of PPROM is directly correlated to maternal age.

  B. Most patients with PPROM before 30 weeks will remain pregnant until at least 34 weeks.

  C. Management at home is a reasonable option for most patients until the onset of contractions.

  D. Patients with bacterial vaginosis are at increased risk for PPROM during pregnancy.

  E. Pulmonary hypoplasia is a common complication of PPROM at this gestational age.

  Correct Answer: D

  Preterm premature rupture of membranes is a relatively common condition, affecting 318.5% of all pregnancies. It is estimated that 30% of all preterm deliveries result from PPROM. There are multiple etiologies for PPROM, including ascending vaginal infection. Carriers of GBS, bacterial vaginosis, and gonorrhea are all at increased risk for PPROM. Maternal age is not a risk factor, nor is parity, maternal weight, maternal weight gain, or trauma. According to most experts, patients with this condition should be managed in the hospital due to the high risk for amniotic infection, preterm labor, and umbilical cord compression or prolapse. Pulmonary hypoplasia and fetal compression malformations are seen when rupture of membranes occurs in the previable period (less than 24 weeks). The duration of latency (time from rupture of membranes to delivery) varies inversely with gestational age. In other words, at term, labor generally begins within hours. However, even at 28 weeks, up to 90% of patients will go into labor within 1 week.

• Question 593:

  A 31-year-old primigravida develops gestational diabetes mellitus and is managed appropriately during pregnancy. She asks you about the consequences of gestational diabetes to her and her fetus. Which one of the following statements is correct?

  A. The risk of fetal anomalies is increased.

  B. The risk of stillbirth is increased if her fasting blood sugars are elevated.

  C. The risk of a growth-restricted newborn is increased.

  D. Insulin is the preferred treatment to maintain euglycemia.

  E. The risk of fetal macrosomia is not increased with gestational diabetes.

  Correct Answer: B

  Unlike women with overt or pregestational diabetes mellitus, the risk of fetal anomalies is not increased in women with gestational diabetes. Stillbirth rates are increased in women with gestational diabetes if their fasting plasma glucose concentrations are elevated, but not with elevated postprandial glucose concentrations only. The risk of a growth-restricted infant is increased in women with long-standing diabetes and vascular disease, but not in women with gestational diabetes. There is a slight increase in the frequency of fetal macrosomia (birth weight over 4000 g), though shoulder dystocia and brachial plexus injury are infrequent.

• Question 594:

  A 37-year-old pregnant woman with type 2 diabetes mellitus and chronic hypertension is 35 weeks' pregnant. Which of the following is the best test to screen for fetal well-being?

  A. nonstress test (NST)

  B. oxytocin challenge test

  C. amniocentesis

  D. fetal movement counting

  E. fetal biophysical profile

  Correct Answer: E

  Of the choices listed, a biophysical profile is the best assessment of fetal well-being. This assesses multiple fetal variables: breathing movement, body or limb movements, tone and posture, fetal heart rate pattern, and amniotic fluid volume. A NST, oxytocin challenge test, and fetal movement counts assess only one determinant of fetal well-being. An amniocentesis has no value in assessing fetal well- being, but may be appropriate to determine fetal lung maturity if induction of labor before 40 gestational weeks is indicated

  because of her chronic illnesses. Fetal Doppler studies to assess systolic:

  diastolic (SD) ratio may be a better test of fetal well-being and a significant decrease or reversal of the

  ratio is an indication for delivery.

• Question 595:

  A 25-year-old woman has a positive cervical culture for Neisseria gonorrhoeae. She has had at least two positive cultures for gonorrhea treated in the past. She is afebrile and has no symptoms. The incidence of penicillin-resistant gonorrhea in some areas of the United States is currently as great as 10%. Because of this, the recommended treatment for gonorrhea includes which of the following?

  A. 125 mg intramuscular ceftriaxone as a single dose

  B. 1 g spectinomycin

  C. 2 g ampicillin orally as a single dose

  D. 2 g intramuscular cefoxitin

  E. 2 g metronidazole as a single dose

  Correct Answer: A

  The current treatment guideline from the Centers for Disease Control and Prevention for uncomplicated gonococcal infections is ceftriaxone 125 mg IM one time. Cefixime 400 mg orally is an alternative. Each is given as a single dose. Importantly, the quinolone class, for example, ciprofloxacin is no longer considered appropriate treatment for gonococcal infections due to drug resistance. To the chosen drug is added azithromycin, 1 g orally, or doxycycline, 100 mg orally twice daily for 7 days. The second drug is added to treat C. trachomatis, which is present in almost 50% of women with gonorrhea. Sexual partners should be treated at the same time

• Question 596:

  A pregnant woman is being followed by a nephrologist for chronic glomerulonephritis. Which of the following findings is normal at 28 weeks' gestation?

  A. blood pressure of 132/86 mmHg

  B. blood urea nitrogen (BUN) of 21 mg/100 mL

  C. serum creatinine of 1.1 mg/100 mL

  D. glomerular filtration rate (GFR) of 130 mL/min

  E. glycosuria with a plasma glucose of 130 mg/100 mL

  Correct Answer: D

  Blood pressure tends to drop slightly in normal pregnancy. This woman's blood pressure of 132/86 mmHg is definitely higher than would be expected and suggests the possibility of chronic hypertension. Because the GFR in pregnancy increases normally by as much as 50% to a peak of approximately 160 mL/min, serum creatinine and BUN should be less than 0.9 and 13 mg/100 mL, respectively. The observed values in this patient are elevated or pregnancy. The renal threshold for glucose normally decreases in pregnancy. Therefore, glycosuria does not always mean diabetes in pregnancy. Several plasma glucose measurements should be obtained in pregnant women with glycosuria to correlate urinary and plasma glucose levels.

• Question 597:

  A 24-year-old nullipara is being evaluated for infertility. On pelvic examination, she has a single cervix. A diagnostic laparoscopy shows a double uterine fundus. Which of the following is the most likely diagnosis of her uterine anomaly?

  A. septate uterus

  B. unicornuate uterus

  C. bicornuate uterus

  D. didelphic uterus

  E. a diethylstilbestrol (DES) exposed uterus

  Correct Answer: C

  Asingle cavity uterus forms from fusion of paired Müllerian ducts followed by dissolution of the fused medial walls. Uterine anomalies can be divided into five distinct categories: A. failure of formation of one or both Müllerian ducts (unicornuate uterus or absent uterus, respectively); B. failure of fusion of the Müllerian ducts (didelphic uterus, with two cervixes and two vaginal canals separated by a longitudinal septum); C. partial fusion of the Müllerian ducts (bicornuate uterus); D. failure of dissolution of the fused medial walls of the Müllerian ducts (septate uterus); and E. DES exposed uterus. Afetus exposed to DES (or any estrogen) in the first trimester will often develop a T-shaped uterine cavity. The pathophysiology of this abnormality is unknown. In this patient, a single cervix and a double uterine fundus indicate a bicornuate uterus.

• Question 598:

  A 58-year-old G6P4Ab2 diabetic woman who weighs 122.6 kg (270 lb) has her first episode of vaginal bleeding in 5 years. Her physician performs an outpatient operative hysteroscopy and dilatation and curettage (DandC). Which of the following is an indication for the procedure and the most likely diagnosis?

  A. endometrial cancer because of her high parity

  B. endometrial cancer because of her obesity

  C. cervical cancer because of her age

  D. cervical cancer because of her diabetes

  E. ovarian cancer because of her obesity

  Correct Answer: B

  Obesity, advanced age, and hepatic disease are associated with an increased risk of endometrial adenocarcinoma. While postmenopausal bleeding is most commonly caused by atrophic changes in the genital tract, cancer must be considered. Cervical cytology and examination of endometrial histology are absolutely indicated. The risk of endometrial cancer is increased approximately threefold in diabetic women, and obese women have a three- to fourfold increased risk. High parity is a risk factor for cervical cancer; low parity is a risk factor for ovarian and endometrial cancer. Postmenopausal bleeding is a sign of ovarian cancer only if the malignancy secretes estrogen to stimulate the endometrium. An office endometrial biopsy has a sensitivity of about 90%. If postmenopausal bleeding persists, a DandC with hysteroscopy should be done. ADandC alone samples about 50% of the endometrium. For this reason, many gynecologists are performing a hysteroscopy and directed endometrial biopsy in addition to a DandC.

• Question 599:

  Which of the following statements is true regarding contraception?

  A. The vaginal contraceptive ring is changed weekly for 3 consecutive weeks, then removed for 1 week to allow for withdrawal bleeding.

  B. Because of effects on the cytochrome P450 system, Depo-Provera should not be used in patients taking antiepileptic drugs (e.g., phenytoin).

  C. Amenorrhea while using the levonorgestrel ntrauterine system (IUD) should raise concern immediately for ectopic pregnancy.

  D. A diaphragm should be inserted no more than 6 hours before intercourse and should remain in place about 6 hours after intercourse.

  E. Failure rate for tubal ligation over 10 years is less than 1 pregnancy per 1000 surgeries performed.

  Correct Answer: D

  Diaphragms can be used successfully for contraception with proper patient education and motivation. Proper fitting is most important for efficacy. The diaphragm should be coated with spermicide prior to insertion (within the dome and along the rim), and inserted no more than 6 hours before intercourse is planned. Conversely, the device should be left in place at least 6 hours but no more than 24 hours after intercourse. If multiple episodes of intercourse take place, additional spermicide should be used. The vaginal ring is designed to be worn for 3 consecutive weeks (i.e., one ring, not three rings changed weekly) and then removed for 1 week. Depo- Provera does not affect liver enzymes but actually increases the seizure threshold, making it a great choice for patients with seizure disorders. Amenorrhea is common (2060%) with patients using the levonorgestrel IUD, and is so effective in preventing pregnancy that this symptom should not raise alarm (as long as other pregnancy symptoms --e.g., nausea and breast

  tenderness--are not present). Over 10 years, tubal ligation failure rates approach 1 per 100 procedures

• Question 600:

  An 11-year-old girl has her first menses. Both ovaries contain approximately how many oocytes?

  A. 7 million

  B. 1 million

  C. 500,000

  D. 50,000 E. 5000

  Correct Answer: C

  The maximum number of oocytes is 67 million at approximately 20 gestational weeks. At birth, the number of oocytes has decreased to about 1 million, and the number at puberty is 300,000500,000. Women at menopause still have a small number of oocytes, a number insufficient to produce an amount of estrogen to prevent vasomotor symptoms. By simple mathematics, women lose approximately 1000 oocytes per menstrual cycle: one by ovulation and the remainder by follicular atresia.