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NBME OBGYN Form 5 - Answers & Explanations

Updated: Nov 16, 2019

Authors: Luke Carlson

Editor: Jordan Abrams

1) Hemorrhagic shock

• Active, prolonged vaginal bleeding

2) Endometriosis

• Ectopic implantation of endometrial glands

• Clinical features: dysmenorrhea, dyspareunia, dyschezia, infertility

3) Dicloxacillin

• Lactational mastitis – tenderness of unilateral breast in lactating patient

• Clinical Features: erythema, tenderness, fever, fissures of nipple

• Pathogenesis – skin flora (eg, Staphylococcus aureus) → clogged, inflamed milk ducts

• Tx: frequent breastfeeding, antibiotics (cover for MSSA – penicillin, penicillinase-resistant)

4) Dehiscence

• Disruption or breakdown of a wound, serosanguineous drainage

• Diabetes mellitus → delayed wound healing → ↑ risk of dehiscence

5) ↓ACTH, ↓TSH, ↓LH, ↓FSH, ↓GH

• Sheehan syndrome: obstetric hemorrhage → hypotension → postpartum pituitary infarction

• Clinical features:

• Anorexia, weight loss, hypotension (↓ ACTH)

• Fatigue, dry skin, constipation, cold intolerance (↓ TSH)

• Amenorrhea, hot flashes, vaginal atrophy (↓ FSH, LH)

• ↓ lean body mass (↓ GH)

• Lactation failure (↓ prolactin)

6) Kell typing of the father’s blood

• Kell antigen system – group of antigens found on RBC surface; help determine blood type

• Anti-Kell antibodies (IgG) – transplacental hemolytic disease of newborn

• Mother tested positive for anti-K, therefore father needs to be tested to determine the risk of fetal K antigen

7) Hepatitis B

• Recommended vaccinations during pregnancy for high-risk patients (eg, multiple STDs)

• Hepatitis B, Hepatitis A, Pneumococcus, Haemophilus influenzae, Meningococcus,

Varicella-zoster immunoglobulin

• ⊖ Hepatitis B surface antigen assay = no Hep B exposure

• Live-attenuated vaccine are contraindicated in pregnancy (eg, MMR, live attenuated influenza, varicella)

8) Influenza virus

• Yearly routine health maintenance examination with all childhood vaccinations no high-risk behavior

9) Ectopic pregnancy

• ⊕ pregnancy test with adnexal mass, vaginal spotting and unilateral abdominal pain

10) Gonadal dysgenesis 45,X (Turner syndrome)

• Primary amenorrhea due to small, non-functioning ovaries (streak ovaries)

• Typical short stature, webbed neck, “shield chest” ( minimal breast development - tanner 3)

11) Vaginal miconazole

• Candida vaginitis tx: antifungal (eg, fluconazole)

• Mild erythema and excoriation (pruritus), no vaginal bleeding or discharge

• Microscopy reveals pseudohyphae

12) Urinary retention

• Inefficient detrusor muscle activity → hypotonic bladder (common postoperative complication)

• Soft symmetric mass extending 25cm above symphysis = distended bladder

• ↑ BUN & creatinine

13) Induction of labor

• Intrauterine fetal demise = fetal death ≥ 20 weeks

• Absence of fetal cardiac activity on US

• Management:

• 20-23 weeks: Dilation and evacuation OR vaginal delivery

• 24 weeks or greater: vaginal delivery

• Complication: coagulopathy after several weeks of fetal retention

• Hb 11g/dL, Hematocrit 32%, Platelets 90,000/mm3

• Missed abortion: no vaginal bleeding, closed cervical os, no fetal cardiac activity

14) Fibroadenoma

• Solitary, well-circumscribed, mobile mass

• Most common cause of breast mass in an adolescent (versus a breast cyst, which is most common after age 30)

• Size & tenderness fluctuate with estrogen exposure → cyclic premenstrual tenderness

15) Herpes simplex virus

• Small, painful vesicles or ulcers on erythematous base (can coalesce), mild lymphadenopathy

• Urine contact on ulcers → Pain with urination

• Patient's systemic symptoms indicate this is a primary HSV infection

16) Thrombus within the pulmonary arteries

• Pulmonary embolism (possibly pulmonary saddle thrombus) → pleuritic chest pain, shortness of breath, hypotension, ↓ SaO₂

17) HIV antibody test

• Recent multiple sexual partners, current STI (gonorrhea or Chlamydia)

• Should also screen for HIV (USPSTF recommends HIV antibody screen 1 time for adults 15-65)

18) Breast

• Adenocarcinoma – glandular (milk ducts or lobules)

• Lymph node drainage:

• Axillary lymph node – breast

• Right supraclavicular lymph node – mediastinum, lung, esophagus

• Left supraclavicular lymph node – thorax, abdomen via thoracic duct

19) Cesarean delivery

• Pregnancy in achondroplasia is considered high risk – cesarean section is usual mode of delivery

• Cephalopelvic disproportion

20) Maternal intramuscular administration of Rho (D) immune globulin now

• RhoD immunoglobulin normally given at 28 weeks AND within 72 hours of any procedure in which there is a possibility of feto-maternal blood mixing (eg, after delivery)

• Other indications for RhoD immunoglobulin administration:amniocentesis, chorionic villus sampling, and external cephalic version

21) Increasing catecholamine

• Cocaine → presynaptic norepinephrine (NE) & dopamine (DA) release, and inhibition of NE, DA and serotonin (5-HT) reuptake

22) Undiagnosed maternal diabetes mellitus

• Diabetes mellitus → excessive weight gain, polyhydramnios, fetal macrosomia

23) Chorioamnionitis

• Prolonged rupture of membranes (>18 hours), prolonged labor, maternal fever, GBS +, leukocytosis, fetal tachycardia

24) Depot medroxyprogesterone

• Depot medroxyprogesterone has no risk of DVT (administered IM every 3 months)

• DDx: acute pelvic infection is an absolute contraindication for placement of IUD, patient would like to have children in the future (tubal ligation not appropriate), patient has trouble remembering (no OCPs or vaginal ring), as well as having DVT (OCP contraindicated)

25) Mature teratoma

• Unilateral, complex adnexal mass; echogenicity on U/S likely due to hair

26) Endometrial biopsy

• Endometrial biopsy is indicated for all women >45 with postmenopausal or abnormal uterine bleeding

27) Testing of the wife first; if negative, no further testing is indicated

• Tay-Sachs disease (autosomal recessive inheritance)

• Ashkenazi Jewish or French Canadian descent

• If mother is not a carrier, then there is no risk of her children receiving two defective genes (even if the father is a carrier)

28) Chronic anovulation

• Unopposed estrogen → excessive proliferation of the endometrium → abnormal uterine bleeding (ie, irregular menses)

• Obesity (BMI >30) is the most common risk factor ( not an answer choice, chronic anovulation next best choice)

29) Pregnancy test

• Nausea, urinary frequency and fatigue are common symptoms of pregnancy

• Patient also has signs of secondary sexual characteristics

• Pregnancy should be ruled out first with urine pregnancy test (cheapest & easiest)

30) Observation only

• Asymptomatic leiomyomata uteri (fibroids) should be managed with observation

31) Appendicitis

• RLQ tenderness, fever, leukocytosis ≈ appendicitis

• Lack of vaginal bleeding or fluid or discharge rules out chorioamnionitis, PID

• Cholecystitis would present with RUQ (not RLQ)

• Lack of flank pain/tenderness rules out pyelonephritis

32) Facial nerve injury

• Forceps delivery → facial nerve (CN VII) lesion → Loss of unilateral facial movement

33) Pyelonephritis

• Flank pain, fever, with WBCs and RBCs on urine microscopy = pyelonephritis

• Physiologic hydronephrosis of pregnancy (bilateral ureteral obstruction) ruled-out with ⊖ kidney U/S findings

• Would expect to find bilateral kidney enlargement and dilation of renal pelvises and

proximal ureters

34) Race

• White race = greatest risk factor for osteoporosis· Other risk factors: low BMI, sedentary

lifestyle, ↑↑ age,

35) Podophyllum resin therapy

• HPV 6, 11 → condyloma acuminata (genital warts)

• Multiple soft pink papillary lesions with areas of pigmentation

• Treatment: Podophyllum resin (arrests mitosis → resulting in cytotoxicity), Trichloroacetic


36) Repeat rapid plasma reagin

• Strong clinical evidence of primary syphilis (painless ulcer with slightly raised edges and shallow base) despite negative RPR 6 weeks ago – repeat RPR is recommended due to possible negative results in early infection

37) Parvovirus

• Patient had classic “slapped-cheek” rash (more commonly seen in children), adults more commonly develop a non-specific rash (seen in this patient)

38) Palpable right ovary

• Ovaries are not commonly palpated on bimanual pelvic examination, therefore palpable right ovary is most concerning (for possible malignancy)

39) Leave the IUD in place, but inform the patient that the leiomyoma may cause heavier menses

• Asymptomatic (no pain, bleeding, discharge) leiomyoma uteri should be managed with observation

40) Maternal fever

• Common cause of fetal tachycardia is maternal fever

41) Insertion of a vaginal pessary

• Easily reducible pelvic organ prolapse can be managed with vaginal pessary

• Management: weight loss, pelvic floor exercises, vaginal pessary, surgical repair

• Surgical repair or additional testing not indicated at this time

42) Ergonovine therapy

• Methylergonovine or ergometrine → uterine contraction (used to treat postpartum hemorrhage)

• Indicated if uterine massage & oxytocin fail to stop bleeding

43) Endometrial ablation

• Surgical destruction of the endometrial lining - used for premenopausal women with heavy, regular menses

• The patient has no desire to become pregnant which aids in the choice for ablation

therapy → chances of becoming pregnant significantly decrease after endometrial


44) Hypotonic contractions

• Montevideo unit = # of uterine contractions per 10 minutes x contraction strength

• Adequate contractions = ≥200 Montevideo units

45) Sterile speculum examination of the vagina

• Patient has PPROM (preterm prelabor rupture of membranes) – rupture of membranes at <37 weeks prior to onset of labor

• Sterile speculum examination has low risk of contamination (→ ↓ risk of chorioamnionitis)

• Digital examination of the cervix (easier access for bacterial entry) a risk factor for


46) Ultrasonography for dating

• 23cm above pubic symphysis would date the fetus at ~23 weeks (not 18 weeks as stated) which would warrant ultrasonography

• Prenatal second-trimester ultrasound is also indicated at 18-20 weeks gestation

47) Prescribe a low-dose oral contraceptive

• Minors are not required to have parental consent for the following:

• Emergency care (all states)

• Sexually transmitted infection (all states)

• Mental health and substance abuse treatment

• Pregnancy care

• Contraception

• Because the patient claims that she is not sexually active yet, Chlamydia trachomatis and Neisseria gonorrhoeae testing is not required at this time

48) Estradiol

• ↓ estradiol production → genitourinary syndrome of menopause (atrophic vaginitis)

• Dysuria, nocturia, frequent urination (urge incontinence)

• Other common findings – vaginal dryness, recurrent UTI, pelvic pressure

49) Succenturiate placental lobe

• Aka accessory lobe of placenta; second or third placental lobe, much smaller than the largest lobe

• Commonly torn from the rest of the placenta as it is delivered; causes postpartum bleeding

50) Uterine rupture

• Sudden decrease in fetal heart rate variability – prolonged fetal heart rate deceleration to 60-70/min for 3 minutes (bradycardia)

• Mother has increasing lower abdominal pain, history of cesarean section

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24) Depot medroxyprogesterone

Patiente DOES NOT have active infection. This question is kinda bad written, because the cut off for IUD is 3 months after the infection. She had the infection 3 months ago. Were it <3 months hands down Depot. But since she had the infection at least 3 months ago, makes it a "not so well written question". Also.... She has trouble remebering to take daily medications. Why can't she have trouble remembering to take the injection in 3 months...? YUP... Exactly...


Oct 02, 2020

really appreciate your hard work doctor!!!

it would be rude if i ask for DDx explanations like number 24 haha i'm just asking.


17) a fluctuant mass in the cul-de-sac can also be indicative of a pelvic abscess, which is more likely in HIV pts (plus her h/o).

4) DM is not an individual risk factor for dehiscence, its actually obesity due to increased tension on the skin. Also serosanguinous discharge is indicative of dehiscence. Hematoma would have shown fluctuant mass (likely to present sooner) and infection would have purulent discharge.


Feb 20, 2020

just want to say thank you for these! these answer explanations are extremely helpful!


Jordan Abrams
Jordan Abrams
Sep 26, 2019

@Drsohika @Stevan we are working on OB/GYN Form 6 explanations and hope to have them posted soon!

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