Case
A 24-year-old woman (gravida 2, para 1, aborta 1) gave birth to a healthy 3.11 kg full-term female baby, with Apgar scores of 10 and 10 at 1 and 5 min, respectively, via spontaneous vaginal delivery at our obstetrics inpatient department. A lateral episiotomy was repaired, and B-ultrasonography revealed that the placenta was lodged in the anterior wall of the uterus, about 31 mm thick, grade III maturity (Figure 1a). Eventually, the entire placenta ejected itself without complications 9 min after the delivery of the baby. The woman’s immediate postpartum course was unremarkable, and bleeding was minimal; she lost about 400 ml of blood during delivery and the post-delivery procedure. However, her hemoglobin levels and platelet counts suddenly dropped from 12.0% prenatal to 7.1% postnatal and from 143 prenatal to 107 postnatal, respectively. Because she had had an arrested intrauterine pregnancy a year before this incidence, she underwent dilation and evacuation (D&E) and was discharged from the hospital on postpartum day 2.
However, the patient returned on postpartum day 12 and complained of a hemorrhage rapidly from the uterus. Her prenatal course had been uneventful, without underlying coagulation defects, medical diseases, or drug exposures. Only one therapeutic arrested intrauterine pregnancy had been documented. Two massive vaginal bleedings had occurred 3 days before her admission and resulted in a total blood loss of about 500 ml. A physical examination had revealed she was drowsy. Hemorrhaging aside, the patient had reported no abdominal pain or anything else. Because she very strongly wished to preserve her fertility, she was transferred to the Reproductive Center of our hospital.
She was hemodynamically stable when she arrived. Her physical examination showed a normal heart rate (90 b.p.m.) and ortho-arteriotomy (126/80 mmHg), but she harbored signs of cyanosis in her extremities and denied experiencing abdominal pain and dizziness. There were also no signs or symptoms of high output heart failure, except her heart rate for 90 b.p.m. at rest. We noted disseminated intravenous coagulopathy, as laboratory data showed severe anaemia (haemoglobin: 6.5 g/dL) and abnormal coagulation tests. As a result, the patient was supplemented aggressively with intravenous fluids and massive blood components (3 units of packed red blood cells).
Subsequently, she underwent conventional ultrasonography(US), which revealed that the hypoechoic area of the uterus anterior wall myometrium close to the endometrium was 2.99 × 1.67 cm with ill-defined edges (Figure 1b). Color Doppler flow imaging (CDFI) exposed a distorted and expanded blood flow signal. Dilated, tortuous vessels were visible on the anterior and left sides of the uterus. Pulsed wave (PW) ultrasound showed a turbulent spectrum and venous blood flow at the peak of systole. Uterine and pelvic blood flow exhibited a high velocity and low resistance, with a peak systolic velocity (PSV) of 78.5 cm/s and a resistance index (RI) of 0.29 (Figure 1c). The initial diagnosis using conventional US was suspicion of a uterine arteriovenous fistula (UAVF).
During hospitalization, postpartum females with uterine atony should be given oxytocin or synthetic prostaglandins to control hemorrhage. Our patient was hemodynamically stable during the first week in the hospital. She communicated her appreciation for the conservative management she received. She was administered oral ferrous sulfate, which normalized her hematocrit and haemoglobin levels; her hemoglobin rose to 8.7 gm%. Her platelet count and coagulation profile were normal.
Yet, a week after her initial complaint, the patient reported sudden “gushes” of bright red blood per vagina on postpartum day 22. Her estimated blood loss was 400 mL. The vaginal bleeding gradually ceased eventually, and she was transfused with 2 units of packed red blood cells and 270 ml of fresh frozen plasma. However, she suffered from an abrupt and profuse vaginal hemorrhage in the uterine cavity again two days later. Her estimated blood loss this time was 800 mL, and her hemoglobin levels dropped from 10.9 to 6.0 g/dl. She was hemodynamically unstable, and a physical examination showed she was drowsy, tachycardic (98 b.p.m.), and hypotensive (88/56 mmHg), with signs of cyanosis in her extremities. She denied having abdominal pain but reported dizziness. We noted disseminated intravenous coagulopathy again, as laboratory data showed severe anaemia (haemoglobin: 6.5 g/dL) and abnormal coagulation tests. The patient was given oxytocin or synthetic prostaglandins to control hemorrhage in postpartum uterine atony, but she failed to respond to treatment. Subsequently, she was supplemented aggressively with intravenous fluids and massive blood components (6 units of packed red blood cells and 6 units of fresh frozen plasma).
Her family requested that a uterine-preserving procedure be couducted if possible. Hence, Pelvic Digital Subtraction Angiography (DSA) was promptly performed, revealing a large AVF over the left uterine artery with active bleeding. The arterial phase during arteriography showed massive dilatation of uterine arteries to accommodate the high-volume shunting through the uterus. Transarterial embolization (TAE) of the bilateral uterine arteries was immediately carried out with microspheres for embolization, occluding the UAVF and active bleeders, as well as the bilateral uterine artery and its branches. Eventually, the vaginal bleeding ceased gradually(Figure S2). The patient was discharged uneventfully four days after the TAE procedure.
She went home on post-procedure day number 1 in stable condition. She was prescribed for ferrous sulfate and instructed to show up for follow-up within 2 weeks.
At the follow-up visit 2 weeks later, the patient had no more episodes of vaginal bleeding.
Hysteroscopic removal of the mass has been planned for day 47 after postpartum, but on hysteroscopic inspection of the uterine cavity, an abnormal cavity 2.99 × 1.67 cm mass consistent with a UAVF was discovered in the upper right uterine cavity (Figure S3).