Identifying Causes of Heavy Menstrual Bleeding

Heavy menstrual bleeding (HMB), or menorrhagia, has a wide range of causes classified under the PALM-COEIN system (structural and non-structural causes). Among the options given, clotting factor deficiency, fibroid uterus, and adenomyosis are all well-established, common causes of HMB, while prolactinoma typically causes the opposite pattern of bleeding. The correct answer is therefore option 2 (1, 2 and 3).

Why the Correct Options Cause HMB

• 1. Clotting factor deficiency: Coagulopathies such as von Willebrand disease and other clotting factor deficiencies impair haemostasis at the endometrial vascular level, leading to prolonged, heavy menstrual flow. This is recognised as the "C" (Coagulopathy) in the PALM-COEIN classification of abnormal uterine bleeding.
• 2. Fibroid uterus: Uterine fibroids (leiomyomas), especially submucosal and intramural types, distort the endometrial cavity, increase endometrial surface area, and interfere with normal myometrial contraction needed to constrict spiral arterioles — all of which lead to heavy and often prolonged bleeding. This is the "L" (Leiomyoma) in PALM-COEIN.
• 3. Adenomyosis: In adenomyosis, ectopic endometrial glands and stroma within the myometrium cause uterine enlargement, impaired contractility, and increased vascularity, classically presenting with heavy, painful menstrual bleeding (menorrhagia with dysmenorrhoea). This is the "A" (Adenomyosis) in PALM-COEIN.

Why Prolactinoma Is Incorrect

• 4. Prolactinoma: Hyperprolactinemia from a prolactin-secreting pituitary adenoma suppresses GnRH pulsatility, leading to reduced LH/FSH secretion and hypoestrogenism. This classically causes oligomenorrhea or amenorrhea (and galactorrhea/infertility) — not heavy menstrual bleeding. Hence, prolactinoma is not a recognised cause of HMB and its inclusion in options 1, 3, and 4 makes those combinations incorrect.

Conclusion

Since clotting factor deficiency, fibroid uterus, and adenomyosis are all classic causes of heavy menstrual bleeding, while prolactinoma is not, the correct combination is 1, 2 and 3, corresponding to option 2.