What are the causes and management options for uterine cramping in a woman of reproductive age?

Management of Uterine Cramping in Reproductive-Age Women

Primary Causes

Uterine cramping in reproductive-age women is most commonly caused by primary dysmenorrhea (painful menstruation without underlying pathology), but structural abnormalities including fibroids, adenomyosis, and endometrial polyps must be ruled out, particularly when cramping is severe or associated with heavy bleeding. 1

Structural Causes (PALM)

• Polyps: Common in women over 40 years presenting with cramping and abnormal bleeding 2
• Adenomyosis: Frequently presents with heavy menstrual bleeding, dysmenorrhea, and dyspareunia, particularly in women in their 40s 3, 1
• Leiomyomas (fibroids): Most common structural cause in women under 40 years with cramping and heavy bleeding 2
• Malignancy/hyperplasia: Must be excluded, especially with risk factors (obesity, diabetes, unopposed estrogen) 2

Non-Structural Causes (COEIN)

• Coagulopathy: Von Willebrand disease and other bleeding disorders should be considered in adolescents with severe cramping and menorrhagia 4
• Ovulatory dysfunction: Can cause irregular cramping patterns 1
• Endometrial disorders: Primary dysmenorrhea related to elevated prostaglandin levels causing myometrial contractions and reduced uterine blood flow 5
• Iatrogenic: Intrauterine devices, anticoagulants (70% of women on anticoagulation experience heavy menstrual bleeding and cramping) 2

Initial Assessment

Mandatory First Steps

• Pregnancy test (β-hCG) must be performed in all reproductive-age women to rule out pregnancy-related causes including ectopic pregnancy and miscarriage 3, 2
• Combined transabdominal and transvaginal ultrasound with Doppler is the first-line imaging study to identify structural causes 2
• Laboratory evaluation should include thyroid-stimulating hormone, prolactin levels, and complete blood count with platelets 3

Physical Examination Findings to Assess

• Hemodynamic stability (urgent evaluation needed if saturating a large pad hourly for ≥4 hours) 2
• Abdominal examination for enlarged uterus or masses 2
• Speculum examination to exclude cervical or vaginal sources 2
• Bimanual examination to assess uterine size, contour, mobility, and adnexal masses 2

Medical Management Algorithm

First-Line Therapy for Primary Dysmenorrhea

NSAIDs are the first-line treatment for primary dysmenorrhea, with ibuprofen 400 mg every 4-6 hours demonstrating superior efficacy by inhibiting prostaglandin synthesis and reducing uterine contractions. 6, 5

• Ibuprofen 400 mg every 4-6 hours starting with earliest onset of pain provides optimal relief; doses greater than 400 mg show no additional benefit 6
• NSAIDs reduce prostaglandin production, decrease intrauterine pressure, and reduce frequency of uterine contractions 6, 5
• Should be taken with meals or milk if gastrointestinal complaints occur 6

Critical caveat: Avoid NSAIDs in patients with cardiovascular disease or post-SCAD due to MI and thrombosis risk 3, 2

Hormonal Therapy Options

Combined hormonal contraceptives (CHCs) are highly effective for dysmenorrhea, particularly when contraception is also desired, and can be used with NSAIDs for additive benefit. 3

• Levonorgestrel-releasing intrauterine device (LNG-IUD) is the most effective medical treatment overall, reducing menstrual blood loss by 71-95% with efficacy comparable to endometrial ablation 3, 1
• The LNG-IUD is preferred in patients with cardiovascular disease where NSAIDs are contraindicated 3, 2
• Oral progestins administered 21 days per month effectively reduce cramping in cyclic heavy bleeding 3

Alternative Pharmacologic Options

• Tranexamic acid is a non-hormonal alternative reducing menstrual blood loss by 20-60%, particularly useful when hormonal therapy is contraindicated 3, 1
• However, tranexamic acid should be avoided in cardiovascular disease due to thrombosis risk 3, 2
• GnRH antagonists (elagolix, linzagolix, relugolix) can reduce bleeding and cramping symptoms 1

Patients on Anticoagulation

• Reassess indication for ongoing antiplatelet therapy and discontinue if appropriate 3, 2
• Progestin-eluting IUDs are preferred due to minimal systemic absorption 3
• Approximately 27% of women on rivaroxaban experience prolonged bleeding (>8 days) compared to 8.3% on warfarin 1

When to Escalate Care

Indications for Further Investigation

• If cramping and bleeding persist despite initial medical therapy, hysteroscopy should be performed to diagnose focal lesions potentially missed by endometrial sampling 3
• Saline infusion sonohysterography has 96-100% sensitivity and 94-100% negative predictive value for uterine pathology 2
• MRI pelvis should be considered when ultrasound findings are indeterminate 2

Referral to Gynecology Required For:

• Failed medical management after appropriate trial 2
• Endometrial sampling showing hyperplasia or malignancy 2
• Postmenopausal bleeding with endometrial thickness ≥4 mm 2

Surgical Management

Endometrial ablation is a less invasive alternative to hysterectomy with efficacy comparable to LNG-IUD for women who have failed medical management and completed childbearing. 3

• Endometrial ablation has long-term complications including postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis; thorough informed consent is essential 3
• Hysterectomy provides definitive resolution when medical management fails or is contraindicated, with significantly better health-related quality of life compared to other therapies 1, 2
• Choose the least invasive surgical route (vaginal > laparoscopic/robotic > abdominal) based on uterine size and surgical expertise 1

Common Pitfalls to Avoid

• Never assume pregnancy is ruled out without testing in any reproductive-age woman with new or worsening cramping 3, 2
• Endometrial biopsy alone should not be used to rule out focal lesions due to variable sensitivity 3
• Do not use NSAIDs or tranexamic acid in patients with cardiovascular disease 3, 2
• Abdominal muscle activity can precede and contribute to cramping pain in primary dysmenorrhea, and this phenotype responds well to NSAIDs like naproxen 7
• Women without this abdominal muscle activity pattern may have central pain sensitization and are more likely to have chronic pelvic pain diagnoses requiring different management approaches 7