Laboratory Studies
Focus routine laboratory studies to discover understood complications of AUB and to also rule out serious medical conditions that can mimic AUB, as follows:
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Complete blood count (CBC), including platelet count and white count differential - Useful for revealing anemia, thrombocytopenia, oncologic concerns, and infections
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Prothrombin time (PT), activated partial thromboplastin time (aPTT), and bleeding time - Useful for detecting possible blood dyscrasias and clotting disorders
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Pregnancy test - Mandatory, even in those patients who deny sexual activity
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Cervical cultures or urine DNA probe - Ordered to test for sexually transmitted infections (STIs) such as chlamydia and gonorrhea, especially if sexual activity is suspected; the overall prevalence of chlamydial infection, the most commonly reported STI in the United States, [23] has been underestimated
Consider the following laboratory studies for patients with AUB who are unresponsive to therapy or who have salient findings on history, physical examination, or initial laboratory studies that suggest a systemic disorder:
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Thyroid-stimulating hormone (TSH) test and free thyroxine (fT4) concentration, to screen for thyroid disease
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Fasting glucose, to rule out occult diabetes
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Prolactin, to rule out hyperprolactinemia [24]
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Dehydroepiandrosterone sulfate (DHEAS), free testosterone, and 17-hydroxyprogesterone (17 OHP), to evaluate for polycystic ovarian syndrome (PCOS)
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vWF:Ag (von Willebrand factor [vWF] antigen), vWF:RCo (vWF ristocetin cofactor) and factor VIII, if von Willebrand disease (vWD) is suspected [25]
Imaging Studies
Pelvic imaging should be reserved for women who do not respond to routine management. Ultrasonography (US), either transabdominal or transvaginal (the latter to be considered only in patients with a history of sexual intercourse or tampon use), is the method of choice for evaluating the female pelvis. [26] It is useful for detecting structural abnormalities of the uterus, [27] PCOS, and ovarian neoplasms. For proper performance and interpretation of this study, an experienced ultrasound technician or practitioner must be available. US sonohysterography may be appropriate for initial imaging and is usually appropriate for follow-up if initial US is inconclusive or further characterization is needed. [26]
A retrospective study by Pecchioli et al questioned the value of routine pelvic US in adolescents with AUB. [28] This study involved a retrospective chart review of 230 adolescent patients younger than 18 years who presented with AUB to the gynecology clinic at the Hospital for Sick Children in Toronto, Canada. The extensive chart review cited the clinical findings on pelvic US and on any additional imaging and described the treatment approaches for these patients. Of the 230 patients, 67.8% (156/230) underwent pelvic US as part of their AUB workup.
In both those patients who were examined with US and those who were not, the most common diagnosis for AUB was an immature hypothalamic-pituitary-ovarian (HPO) axis. [28] Of the patients who underwent US, 72.4% (113/156) had normal findings, 17.9% (28/156) had incidental findings, and 6.4% (10/156) had PCOS morphology. Structural causes of AUB were found in only two (1.3%) of the adolescents imaged. In none of the patients who underwent US did the findings from imaging lead to a change in the AUB treatment plan. The results of this study strongly suggest that pelvic US should not be a required part of the initial investigation of AUB in adolescents.
Other imaging modalities that may be considered in the workup of AUB are magnetic resonance imaging (MRI) and computed tomography (CT). MRI has adequate resolution, but it is only rarely superior to US and is quite expensive; however, it is considered to be usually appropriate if initial US is inconclusive or further characterization is needed. [26] CT can be useful in the workup of adolescent females with a confirmed neoplasm. Before CT is performed, it is important to weigh the benefit against the risk so as to avoid unnecessary exposure of the pelvic region to radiation.
Procedures
Referral to a coordinated Women's Health Care/Gynecology Care Team is recommended for these treatment approaches:
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Uterine curettage is rarely indicated in the adolescent with AUB; it is usually reserved for women with significant and prolonged hemorrhage that is unresponsive to standard medical therapy
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Diagnostic hysteroscopy can be used to look for structural abnormalities as a cause of persistent AUB
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Sonohysterography is a less invasive but less accurate method of evaluating the uterine cavity; it consists of injecting fluid into the uterus under US visualization [26]
Histologic Findings
Endometrial biopsy is rarely required and should be reserved for adolescents with uterine bleeding that is unresponsive to standard medical intervention. Endometrial curettage often demonstrates a disordered proliferative pattern without secretory activity (absence of progesterone effect). Findings from endometrial biopsies in patients who currently are receiving hormonal therapy can demonstrate hormonal effects and hence may interfere with biopsy interpretation.
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Menstrual cycle.
