What are the differential diagnoses for hypogastric pain in women?

Differential Diagnoses for Hypogastric Pain in Females

The differential diagnosis of hypogastric pain in women must be systematically approached by first ruling out pregnancy-related emergencies, then considering acute gynecologic pathology, followed by non-gynecologic causes including gastrointestinal, urologic, and musculoskeletal etiologies. 1

Immediate Priority: Pregnancy-Related Causes

In Reproductive-Age Women

• Ectopic pregnancy is the most life-threatening cause and must be excluded first with serum β-hCG testing, even if urine pregnancy test is negative 2
• Spontaneous abortion (miscarriage) should be considered in any patient with acute pelvic pain and a positive pregnancy test 1
• Complications of intrauterine pregnancy (threatened abortion, placental abruption) are critical differential diagnoses in pregnant patients 1
• Three months of amenorrhea with recent spotting is a classic presentation for ectopic pregnancy, reflecting decidual bleeding from inadequate hCG support 2

Acute Gynecologic Causes (Non-Pregnancy)

Reproductive-Age Women

• Adnexal torsion must be ruled out promptly and is identified by an asymmetrically enlarged ovary with a twisted pedicle on imaging 1
• Tubo-ovarian abscess should be included in the work-up when infection is suspected 1
• Pelvic inflammatory disease should be considered, particularly with recent sexual activity or instrumentation 1, 3
• Ruptured ovarian cysts can present with acute hypogastric pain 1

Postmenopausal Women

• Ovarian cysts account for approximately one-third of gynecologic causes of acute pelvic pain in peri- and postmenopausal patients 1
• Uterine fibroids are the second most common gynecologic cause, presenting with torsion of pedunculated fibroids, prolapse of submucosal fibroids, or acute infarction/hemorrhage in degenerating fibroids 1
• Pelvic infection (≈20% of cases) includes tubo-ovarian abscess, oophoritis, salpingitis, endometritis, cervicitis, or peritonitis 1
• Ovarian neoplasm represents about 8% of acute pelvic pain cases and should be prioritized because of malignancy risk 1
• Rare etiologies include ovarian torsion, retained intrauterine device, and reactivated endometriosis (in patients on hormone therapy) 1

Chronic/Subacute Gynecologic Causes

When Vaginal Bleeding or Adnexal Mass Present

• Evaluation for endometrial and ovarian malignancy must take precedence when vaginal bleeding or a suspected adnexal mass is present 1

Other Chronic Gynecologic Causes

• Pelvic venous disorders (pelvic congestion syndrome) are a recognized cause of deep pelvic pain 1
• Endometriosis is one of the most widespread gynecological disorders and commonly presents with low back pain spreading to the hypogastric, inguinal, and pubic areas 4
• Intraperitoneal adhesions can produce chronic deep pelvic discomfort 1
• Hydrosalpinx is an important gynecologic source of persistent deep pelvic pain 1
• Chronic inflammatory disease (e.g., chronic PID) may underlie deep pelvic pain 1
• Cervical stenosis is another possible contributor to deep pelvic pain 1
• Vaginal atrophy is a common cause of perineal, vulvar, or vaginal pain in postmenopausal women 1
• Vaginismus should be considered when pain is associated with attempted vaginal penetration 1
• Vaginal or vulvar cysts can produce localized pain 1
• Vulvodynia is a recognized chronic pain condition affecting the vulvar region 1
• Pelvic myofascial pain contributes to chronic pelvic discomfort 1

Non-Gynecologic Causes

Gastrointestinal

• Gastroenteritis and nonspecific abdominal pain are the most common causes of acute abdominal pain overall 3
• Appendicitis is a frequent cause of lower abdominal pain and has a characteristic clinical presentation that can be diagnosed by CT or ultrasound 3, 5
• Diverticulitis should be considered, particularly in older patients, and can be reliably diagnosed with CT or ultrasound 1, 5
• Bowel obstruction is an additional gastrointestinal cause 1
• Appendicitis epiploica should be recognized to avoid unnecessary operations 5

Urologic

• Urolithiasis is a common cause of lower abdominal pain and may be diagnosed clinically in certain cases 3
• Obstructive uropathy and urinary tract infection are relevant urologic differentials 1

Vascular

• Abdominal aortic aneurysm and venous thrombosis are additional possible causes 1

Musculoskeletal

• Abdominal wall pain should be considered as an extra-abdominal cause 3
• The iliopsoas syndrome, diagnosed by sonopalpation, often remains undetected 5

Critical Diagnostic Pitfalls

• Never exclude ectopic pregnancy based solely on a negative urine pregnancy test in a patient with amenorrhea and pelvic pain; serum β-hCG is required 2
• Do not assume spotting represents normal menstruation; it may be decidual bleeding from an ectopic gestation 2
• Non-gynecologic causes should not be overlooked; roughly 15% of women presenting with acute pelvic pain are postmenopausal, making urinary, gastrointestinal, and vascular etiologies more prominent 1
• Strict research definitions should not replace clinical judgment; patients with symptom duration <3 months may still require evaluation based on pain severity alone 1

Diagnostic Approach Algorithm

Step 1: Assess Hemodynamic Stability

• If unstable, consider ruptured ectopic pregnancy, ruptured ovarian cyst with hemorrhage, or ruptured abdominal aortic aneurysm 1, 2

Step 2: Pregnancy Testing

• Obtain serum β-hCG immediately in all reproductive-age women, even with negative urine test 2
• If positive, perform transvaginal ultrasound to assess for intrauterine vs ectopic pregnancy 2

Step 3: Imaging Selection Based on Clinical Presentation

• Transvaginal ultrasound is the study of choice for suspected gynecologic pathology 3, 6
• Computed tomography with intravenous contrast is often chosen for generalized abdominal pain, left upper quadrant pain, and lower abdominal pain 3
• Ultrasonography is the study of choice for right upper quadrant pain 3
• Point-of-care ultrasonography can aid in prompt diagnosis of cholelithiasis, urolithiasis, and appendicitis 3

Step 4: Laboratory Testing

• Complete blood count, C-reactive protein, hepatobiliary markers, electrolytes, creatinine, glucose, urinalysis, lipase, and pregnancy testing 3