Meta-analysis on the use of hyaluronic acid gel to prevent intrauterine adhesion after intrauterine operations.

Intrauterine adhesion (IUA) is a severe complication that occurs following abortion, and hyaluronic acid gel has been used to prevent IUA following intrauterine operation. The present study aimed to systematically evaluate the efficacy of hyaluronic acid gel in preventing IUA following intrauterine operation. In the current study, a literature search was performed using PubMed, Cochrane Library and EMbase databases for randomized controlled clinical trials that used hyaluronic acid gel as an adjuvant therapy following intrauterine operation. The terms 'hyaluronic acid', 'intrauterine adhesions', 'Asherman's syndrome', 'IUA', 'dilatation and curettage', 'abortion' and 'hysteroscopic' were used to search for articles published online before July 31, 2018. RevMan 5.3 software was used to analyze the indicators of uterine cavity adhesion formation and pregnancy rates following intrauterine operation. A total of seven randomized controlled clinical studies were included, consisting of 952 patients who underwent intrauterine operation. The meta-analysis indicated that the use of hyaluronic acid gel reduced the incidence of IUA [relative risk (RR)=0.42; 95% confidence interval (CI)=0.30-0.57; P<0.001] and the score for IUA after an intrauterine operation (mean difference=-1.29; 95%=-1.73 to -0.84; P<0.001). A subgroup analysis revealed that the preventive effect of hyaluronic acid gel on IUA was not affected by the type of intrauterine operation, namely abortion (RR=0.40; 95% CI=0.26-0.62; P<0.001) and hysteroscopy (RR=0.44; 95% CI=0.28-0.68; P<0.001). The preventive effect of hyaluronic acid gel on IUA was also not affected by primary disorders/diseases including the following: Abortion (RR=0.48; 95% CI=0.29-0.78; P=0.003); IUA (RR=0.38; 95% CI=0.21-0.67; P<0.001) and submucosal myoma of the uterus, endometrial polyps or mediastinum uterus (RR=0.40; 95% CI=0.18-0.90; P=0.03). Hyaluronic acid gel improved pregnancy rates after intrauterine operations (RR=1.94; 95% CI=1.46-2.60; P<0.001). In conclusion, hyaluronic acid gel was indicated to significantly reduce the incidence of IUA following intrauterine operation, regardless of the type of intrauterine operation or the presence of primary diseases. Treatment with hyaluronic acid gel was also revealed to increase pregnancy rates following intrauterine operation.