PLAB Obstetrics & Gynecology Flashcards

A 28-year-old woman at 32 weeks gestation presents with sudden-onset severe headache, visual disturbances, and BP of 160/110 mmHg. What is the most likely diagnosis?

Answer: Pre-eclampsia

Pre-eclampsia is defined by hypertension (≥140/90 mmHg) with proteinuria or end-organ dysfunction after 20 weeks gestation, and severe features include BP ≥160/110 mmHg with neurological symptoms.

Which medication is first-line for cervical ripening and labor induction in a patient with an unfavorable cervix at term?

Answer: Dinoprostone (prostaglandin E2)

Dinoprostone (prostaglandin E2) gel or insert is the standard first-line agent for cervical ripening in patients with an unfavorable Bishop score at term.

A 35-year-old woman presents with sudden severe lower abdominal pain, shoulder tip pain, and a positive urine pregnancy test. Ultrasound shows no intrauterine pregnancy. What is the most likely diagnosis?

Answer: Ruptured ectopic pregnancy

Ruptured ectopic pregnancy classically presents with acute abdominal pain, peritoneal irritation causing referred shoulder tip pain (diaphragmatic irritation from hemoperitoneum), and a positive pregnancy test without intrauterine pregnancy on ultrasound.

Which investigation is most useful to confirm ovarian torsion in a woman presenting with acute unilateral pelvic pain?

Answer: Transvaginal ultrasound with Doppler

Transvaginal ultrasound with Doppler flow studies is the first-line investigation for suspected ovarian torsion, assessing ovarian morphology and blood flow, though absence of flow is not always present.

A primigravida at 38 weeks presents with mild contractions and her cervix is 4 cm dilated, fully effaced, with the fetal head at 0 station. What stage of labor is she in?

Answer: Active phase of first stage

The active phase of the first stage of labor begins at 6 cm dilation in most modern guidelines, but reaching 4 cm effaced with regular contractions is transitioning into active labor; cervical dilation ≥6 cm with contractions defines active phase per ACOG 2014 guidelines.

Which antibiotic is recommended for Group B Streptococcus (GBS) prophylaxis during labor in penicillin-allergic patients with low anaphylaxis risk?

Answer: Cefazolin

Cefazolin is the recommended alternative for GBS intrapartum prophylaxis in penicillin-allergic patients with low risk of anaphylaxis (no history of urticaria, angioedema, or anaphylaxis to penicillin).