Abnormal uterine bleeding is a common but complicated clinical presentation that impairs the quality of life in women. The causes of abnormal uterine bleeding are varied, depending largely on the age and life stage of the women. The common causes in women of reproductive age include pregnancy and pregnancy-related disorders, medications, iatrogenic causes, systemic conditions, genital tract pathology, and dysfunctional uterine bleeding (anovulatory or ovulatory). The rare ones are genital cancers [1]. In this report, we reported a case of abnormal uterine bleeding of unknown reason in a reproductive-aged woman who presented a heavy bleeding after the normal last menstrual period.

A 32-year-old female had the normal last menstrual period from October 1, 2014 to October 8, 2014. Since October 17, 2014, she had a heavy bleeding form virginal without any significant incentives. Taking a three-day hemostatic drug treatment was not effective. Therefore, the diagnostic uterine curettage was taken at the clinic. She visited a local hospital on October 26, 2014 because of the constant bleeding after operation, and her blood results were as follows: hemoglobin 7.5 g/dL, beta-human chorionic gonadotropin (β-hCG) < 1.2 mIu/ml. Transvaginal ultrasound showed that the thickness of endometrial was about 2 mm, with uterine cavity effusion and pelvic cavity effusion in small quantities. The hysteroscopy was performed on November 3, 2014 the depth of uterine was 7.5 cm, the cervical showed no obvious placeholder lesions and special-shaped vessels and no aliens vascular and space-occupying lesions, and the openings of bilateral fallopian tube were clear. Blood hemoglobin was 5.5 g/dL, after blood transfusion hemoglobin increased to 7.7 g/dL. Marvelon (3 pills daily) was given after the hysteroscopy, and then the bleeding gradually reduced.

The patient was sent to our hospital by ambulance with heavy bleeding again on November 15, 2014. She was pale with cold clammy skin and her blood pressure was 106/72 mmHg. Speculum examination showed moderate bleeding coming through the cervical os with around 150 mL of clots. Bimanual examination revealed a softer uterus in normal size. Her abdomen was soft and non-tender and no mass was palpable. The patient denied the use of medications and had no significant past medical history. Her blood results were as follows: urine pregnancy test was negative, hemoglobin was 8.8 g/dL, thrombin time was 21.8 s/20 s. Transvaginal ultrasound showed endometrial cavity fluid(60x35 mm)most likely hematometra, but no obvious adnexal mass. Progynova (12 mg daily) was administrated for three days, but was ineffective. Hemoglobin was 5.06 g/dL on November 18, 2014 then blood transfusion was performed and the dose of progynova was increased to 16 mg daily. In addition, oxytocin and intrauterine balloon pipe were added in the treatment. As the cause of bleeding could not be determined from any coagulation disorder or observed from a scar site, we performed pelvic magnetic resonance imaging and uterus CTA and the results were normal. The bleeding gradually reduced and stopped on November 23, 2014. Transvaginal ultrasound was performed on December 3, 2014 and the results showed that the thickness of endometrial was about 6 mm and no obvious adnexal mass was observed.

Abnormal uterine bleeding in reproductive-aged women is a manifestation of a number of disorders or pathologic entities. In the clinical, women of reproductive age with heavy bleeding should be given immediate intervention to prevent further blood loss [2] [3]. The follow-up is largely dependent on whether they require investigation and ongoing care for some underlying diseases. Thus it is important to find the cause of bleeding.

The cause of abnormal uterine bleeding in reproductive-aged women may be organic or non-organic. Blood test, vaginal examination, endometrial curettage, ultrasound, and hysterogram are helpful in the diagnosis and differential diagnosis [4]. For cases not responding to conservative treatment, pelvic angiogram and magnetic resonance imaging scan, even hysteroscopy may be performed to detect the lesions in the uterus.

In our case, we performed the sequential steps of the differential diagnosis as described previously [1]. By physical examination, laboratory and imaging tests, the pregnancy, iatrogenic cause, systemic condition and genital tract pathology were excluded. Then we suspected a dysfunctional uterine bleeding [1]. However, haemostatic and hormones, even the curettage could not stop the heavy bleeding [5][6]. The biopsy of endometrial showed secretory phase in accordance with the patient's menstrual cycle (the 21st day of menstrual cycle) (Figure 1). By bimanual examination, the uterus was found softer than normal, and the bleeding gradually stopped only after oxytocin and intrauterine balloon pipe treatment in addition to high doses of estrogen. Therefore, the cause of bleeding cannot be attributed to dysfunctional uterine bleeding. The unexplained uterine contractions fatigue and some unknown factors may be the causes of abnormal uterine bleeding in this case.

Abnormal uterine bleeding is one of the most common reasons that reproductive-aged women seek health care. Medical history, physical examination, and laboratory evaluation help the physician find the causes and give suitable therapy. In rare complicated cases, however, the causes cannot be identified which will lead to a delay in treatment and significant loss of blood.

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