Role of low-molecular-weight heparin in altering uterine artery blood flow in recurrent spontaneous abortion: a prospective study

OBJECTIVE: This study aimed to determine the role of uterine artery blood flow (UABF) in recurrent spontaneous abortion (RSA) and to determine a viable option to promote the outcome of pregnancy. METHODS: A total of 421 women were prospectively recruited for this research. UABF indices, including the systolic/diastolic ratio, pulsatility index and resistance index, during the midluteal phase were compared between patients with RSA and women without RSA (controls). After low-molecular-weight heparin (LMWH) was administered to patients with RSA, indices at 7, 10, and 12 weeks of gestation were compared between the two groups. RESULTS: UABF indices during the midluteal phase were significantly higher in the RSA group than in the control group. After LMWH was administered to the RSA group, UABF indices in the first trimester were similar to those in the control group. The rate of spontaneous miscarriage was also similar between the groups after LMWH treatment. CONCLUSIONS: Our study shows that sufficient uterine perfusion is crucial for a successful pregnancy. LMWH reduces the rate of spontaneous miscarriage in patients with RSA to a similar rate in women without RSA. LMWH might play a role in decreasing UABF resistance and increasing uterine perfusion.