Objective: To evaluate the effects of low-dose aspirin on placental circulation and on the prevention of intrauterine growth retardation (IUGR).
Material and methods: We conducted a prospective randomized, double blind, controlled clinical trial in 84 pregnant women (mainly nulliparous women) at high risk of IUGR. From the 28th-30th week of gestation onward, low dose aspirin (75 mg daily, study group, n = 40) or placebo (control group, n = 44) was given consecutively for 6 to 8 weeks. Pulse-wave umbilical artery Doppler velocimetry was measured before and after drug use.
Results: The mean value of systolic/diastolic ratio of umbilical artery flow velocity waveforms in the study group was significantly lower than that in the control group after drug use, but there was no difference between the two groups before drug use. The incidences of IRGR and preeclampsia in the study group (7.5% and 10.0% respectively) were significantly lower than those in the control group (27.3% of both). No adverse effects of low dose aspirin on both mother and fetus were observed.
Conclusions: Low dose aspirin administration (75 mg daily) beginning at the early stage of third trimester may improve the fetoplacental circulation, and thus prevent IUGR and/or preeclampsia effectively.