Abnormal Uterine Bleeding Workup
A 45-year-old woman presents with continuous vaginal bleeding for 15 days, soaking six pads daily. She feels lightheaded on standing and has fainted twice. Pulse is 108 beats/min and supine blood pressure is 100/62 mm Hg. She is sexually active and uses no contraception. Which of the following is the most appropriate initial investigation?
- A.Transvaginal pelvic ultrasound scan
- B.Qualitative urine pregnancy test
- C.Complete blood count and serum beta-hCGCorrect
- D.Diagnostic dilatation and curettage
Explanation
Prolonged heavy bleeding with presyncope, syncope, and tachycardia points to significant blood loss, so the first investigations must quantify the anaemia and exclude pregnancy as the cause. A complete blood count gives the haemoglobin that determines whether transfusion is needed and shows platelet count, which may itself explain the bleeding. Serum beta-hCG is mandatory in any woman of reproductive age with abnormal bleeding because pregnancy complications, including ectopic pregnancy, incomplete miscarriage, and gestational trophoblastic disease, can present exactly this way and change management entirely. At 45 she is very likely still ovulating intermittently and uses no contraception, so pregnancy cannot be assumed absent. These two tests are cheap, immediate, and directly alter the next decision, which is why they precede imaging. Pelvic ultrasound is important later to assess endometrial thickness, fibroids, polyps, and adnexal masses, but it neither measures blood loss nor excludes pregnancy. A urine pregnancy test is a reasonable bedside screen, yet serum beta-hCG is more sensitive and quantitative in the emergency setting and is obtained with the same venepuncture as the blood count. Dilatation and curettage may follow later for tissue diagnosis, since endometrial sampling is indicated in a woman over 45 with abnormal bleeding, but it is a therapeutic and diagnostic procedure, not a first-line test. Group and save should also be sent.
Why each option
- A.
- Ultrasound characterises the uterus and endometrium but is a second step; it neither measures haemoglobin nor excludes pregnancy.
- B.
- A urine test is a useful bedside screen but is less sensitive and quantitative than serum beta-hCG in an acutely bleeding patient.
- C.
- Correct. The blood count grades the anaemia and directs transfusion, while beta-hCG excludes pregnancy-related causes of the bleeding.
- D.
- Curettage is invasive and belongs later in the pathway once pregnancy is excluded and imaging has been performed.
Reference: ACOG Practice Bulletin 128 (reaffirmed 2023), Diagnosis of Abnormal Uterine Bleeding in Reproductive-Aged Women
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