Application of low molecular weight heparins in umbilical artery thrombosis: A case series and review of the literature

Low molecular weight heparins are widely used in various thrombotic diseases and exert a preventive effect on thrombosis in high-risk patients. Umbilical artery thrombosis (UAT) is a rare occurrence that is difficult to detect during routine prenatal visits but can lead to adverse perinatal outcomes. PATIENT CONCERNS: The aim of this study was to elucidate the therapeutic effect of low molecular weight heparins on UAT and to provide a new treatment option for the timing of delivery timing. DIAGNOSES AND INTERVENTIONS: A retrospective study was conducted on cases involving thrombosis of the umbilical cord enrolled from July 2017 to July 2022. Data were acquired and analyzed from medical records and the final diagnosis was confirmed by histopathology. All included patients received LWMHs therapy after initial diagnosis of UAT. OUTCOMES: The mean age of the 10 pregnant women recruited into this study was 27.9 ± 4.0 year-of-age; 1 (10%) was elderly. The gestational age at diagnosis was 29.9 ± 3.7 weeks, the gestational age at termination was 36.3 ± 2.5 weeks and the mean gestational age of extension was 6.4 ± 4.2 weeks. Low molecular weight heparin sodium was administered after umbilical artery embolism was detected on ultrasound. The LWMHs treatment received by the included patients in this study was subcutaneous injection. The specific usage varies due to the types of LWMHs. Of the 10 cases, 5 (50%) had fetal distress but all fetuses were born alive without neonatal asphyxia. With regards to delivery mode, 9 pregnancies were terminated by cesarean section. LESSON: Early anticoagulant treatment with LWMHs may improve pregnancy outcomes. The timing and mode of termination of pregnancy should be determined according to the condition of the mother and the fetus along with the gestational age.