RESUMEN
BACKGROUND: With in vitro fertilization (IVF) techniques, only 20-25% of the transferred embryos lead to a pregnancy. OBJECTIVE: To evaluate the beneficial effects of seminal plasma (SP) or semen applied at the time of oocyte aspiration or embryo transfer. SEARCH STRATEGY: Electronic databases were searched from their inception up to August 2017. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) evaluating the effects of SP or semen in IVF treatment. Trials were considered if women were exposed to any kind of SP or semen (either SP/semen injection or sexual intercourse) around the time of oocyte pickup and embryo transfer. DATA COLLECTION AND ANALYSIS: The primary outcome was clinical pregnancy rate (CPR). MAIN RESULTS: Eight RCTs on women undergoing IVF (2128 in total) were included in the meta-analysis. Women randomized in the intervention group had a significantly higher CPR compared with controls (30.0 versus 25.1%; RR 1.20; 95% CI, 1.04-1.39). No significant differences were found in the secondary outcomes, including livebirth rate, biochemical pregnancy, miscarriage, multiple pregnancies, and birth weight. The subgroup analyses (four RCTs, 780 participants), including only those RCTs in which prepared undiluted SP was injected just after oocyte pickup, conformed with the overall analysis for the primary outcome (46.3 versus 37.2%; RR 1.23; 95% CI, 1.05-1.45). CONCLUSION: Because intravaginal or intracervical SP application around the time of oocyte pickup is associated with higher CPR, local application SP may be considered as a potential treatment to improve implantation. TWEETABLE ABSTRACT: SP at the time of oocyte pickup is associated with higher CPR.