The Application of aspirin/low-molecular-weight heparin to improve uterine blood flow perfusion in pregnant women with recurrent pregnancy loss

Abstract

OBJECTIVES: The purpose of this study was to evaluate differences in uterine artery blood flow parameters (uterine artery resistance index [RI]) between healthy women and those with recurrent pregnancy loss (RPL) in the mid-luteal phase and early pregnancy. Additionally, it investigated the clinical effects of low-dose aspirin (LDA), low-molecular-weight heparin (LMWH), and LDA combined with LMWH on the pregnancy outcomes of pregnant women with RPL and abnormal uterine blood flow perfusion. METHODS: From January 2021 to June 2023, women of childbearing age admitted to the Second Affiliated Hospital of Soochow University were recruited for the study (242 women with RPL and 135 healthy women). All participants were scanned transvaginally with Doppler sonography in the mid-luteal phase to measure the RI of the left and right main uterine arteries. Drugs were administered to pregnant women with RPL and an abnormal uterine artery RI (n=133). According to the drug regimen, participants were divided into the aspirin group (n=14, 100 mg orally, once daily), LMWH group (n=37, 4100 U subcutaneously, once daily), and combined treatment group (n=82). The uterine blood flow perfusion parameters (uterine artery RI) of the treatment groups and controls (52 cases of normal pregnancy) in early pregnancy were compared, along with pregnancy outcomes, including miscarriage, live birth, preterm birth, full-term living birth, pregnancy complications, and neonatal birth condition. RESULTS: In the mid-luteal phase, the mean ± standard deviation of the uterine arterial RI (right side, left side, and average) in women with RPL was 0.82±0.08; in healthy women, it was 0.80±0.07, 0.80±0.06, and 0.80±0.06, respectively. The differences between the two groups were statistically significant (P<0.05). The abortion rates of the aspirin group, LMWH group, combination therapy group, and normal pregnancy group were 21.4%, 32.4%, 22.0%, and 16.7% respectively, with no statistically significant differences (P>0.05). The risk of pregnancy complications (such as abortion, preeclampsia, and fetal growth restriction) in the aspirin group, LMWH group, combination therapy group, and normal pregnancy group was 50.0%, 37.8%, 35.4%, and 31.5%, respectively, with no statistically significant differences (P>0.05). CONCLUSIONS: The uterine arterial RI of women with RPL was higher than that of healthy women in the mid-luteal phase. Treatment with aspirin, LMWH, and a combination thereof in early pregnancy could effectively reduce the RI of the uterine artery in pregnant women with RPL and an abnormal uterine artery RI, and the incidence of adverse pregnancy outcomes (such as abortion, preeclampsia, and fetal growth restriction) did not differ from that among healthy pregnant women. There was no difference in the treatment effect of aspirin, LMWH, and combined medication in early pregnancy among women with RPL and an abnormal uterine arterial RI. Single-drug treatment with aspirin or LMWH is recommended clinically.