What is the appropriate workup for an 18-year-old female presenting with irregular menstrual bleeding and pelvic pain?

From the Guidelines

For an 18-year-old female with irregular bleeding and pelvic pain, the initial workup should include a thorough history, physical examination, pregnancy test, complete blood count, and pelvic ultrasound, as recommended by the most recent guidelines 1. The initial step in the workup should be to rule out pregnancy complications like ectopic pregnancy or miscarriage with a urine or serum hCG test. Obtaining a detailed menstrual history including cycle length, bleeding duration, and associated symptoms is crucial. Physical examination should include vital signs, abdominal examination, and pelvic examination if appropriate. Laboratory tests should include CBC to assess for anemia, TSH to rule out thyroid dysfunction, and STI testing including gonorrhea and chlamydia, as suggested by the guidelines 1. Transvaginal or transabdominal ultrasound can identify structural abnormalities like fibroids, polyps, ovarian cysts, or endometriosis, as noted in the ACR Appropriateness Criteria 1. Consider hormonal causes like polycystic ovary syndrome (PCOS) or thyroid disorders. Initial management may include NSAIDs like ibuprofen 600-800mg every 6-8 hours for pain and hormonal contraceptives like combined oral contraceptives (e.g., 20-30 μg ethinyl estradiol) to regulate bleeding, as recommended by the guidelines 1. If endometriosis is suspected, a trial of hormonal suppression with continuous oral contraceptives or norethindrone acetate 5-10mg daily may be appropriate. Referral to gynecology is warranted if there are concerning findings on ultrasound, severe symptoms, or if initial management is unsuccessful after 2-3 months, as suggested by the guidelines 1 and the ACR Appropriateness Criteria 1. Some key points to consider in the workup and management of irregular bleeding and pelvic pain in an 18-year-old female include:

• Ruling out pregnancy complications with a urine or serum hCG test
• Obtaining a detailed menstrual history and performing a physical examination
• Ordering laboratory tests such as CBC, TSH, and STI testing
• Performing a transvaginal or transabdominal ultrasound to identify structural abnormalities
• Considering hormonal causes and initial management with NSAIDs and hormonal contraceptives
• Referring to gynecology if necessary, as recommended by the guidelines 1 and the ACR Appropriateness Criteria 1.

From the Research

Initial Evaluation

• The patient presents with irregular bleeding and pelvic pain, which are common symptoms of ectopic pregnancy 2, 3.
• A pregnancy test should be performed to determine if the patient is pregnant, as ectopic pregnancy is a life-threatening condition that requires prompt diagnosis and treatment 2.

Diagnostic Approach

• Pelvic ultrasound is the primary imaging modality used to diagnose ectopic pregnancy, as it can help differentiate between an ectopic pregnancy and a normal or abnormal intrauterine pregnancy 3.
• The definitive diagnosis of ectopic pregnancy can be made with ultrasound visualization of a yolk sac and/or embryo in the adnexa, but this is not always possible 2.
• Serial beta human chorionic gonadotropin (β-hCG) levels and serial ultrasonography can be used to make the diagnosis, especially in cases where the pregnancy is of unknown location 2.

Laboratory Tests

• β-hCG levels should be measured to help diagnose ectopic pregnancy, as well as to monitor the patient's response to treatment 2.
• Other laboratory tests, such as complete blood count and blood type, may also be performed to evaluate the patient's overall health and to prepare for potential surgery 2.

Imaging Features

• The ultrasound should be carefully evaluated for signs of ectopic pregnancy, such as an adnexal mass or free fluid in the pelvis 3.
• The ultrasound technician should be familiar with the common pitfalls and troubleshooting tips for diagnosing ectopic pregnancy, such as avoiding mistaking a corpus luteum for an ectopic pregnancy 3.