Clinical Efficacy of Doppler Ultrasound for Low Dose Aspirin Therapy in High Risk Pregnancy

Abstract

We investigated the capacity of low dose aspirin in reducing the incidence of pregnancy induced hypertension and affecting the pregnancy outcomes in women at high risk for this disorder. And we also studied the efficacy of Doppler ultrasound as an effective means of selecting a patient population of good candidate to administer low dose aspirin. Seventy women with chronic hypertension or a history of severe preeclampsia in their previous pregnancy were randomly assigned to treated group receiving low dose aspirin(60 mg/d, n=32) or control group(n=38). Daily administration of low dose aspirin could not prevent the development of pregnancy induced hypertension in the treated group(21.9% vs. 28.3%, p>0.05). And there was no differences between the treated and control groups in the rates of emergency cesarean section for fetal distress(6.3% vs. 10.3%, p>0.05), neonatal intensive care unit admission(9.4% vs. 15.8%, p>0.05), fetal growth retardation(15.6% vs. 13.2%, p>0.05), and perinatal death(3.1% vs. 7.9%, p>0.05). In the group showing abnormal Doppler flow velocity waveform, aspirin seemed to improve the mean gestational age(35.7±2.8 vs. 34.4±3.1 weeks), birth weight(2271.9±730.8 vs. 1887.0±619.0 gm) and the pregnancy outcomes(31.3% vs. 60.6%), however, these results were not statistically significant(p>0.05). This study suggests that low dose aspirin therapy is not effective in reducing the incidence of pregnancy induced hypertension. However, combination of Doppler ultrasound study with low doe aspirin therapy may improve pregnancy outcomes in women with high risk pregnancy.