Introduction: Bed rest for the variable duration is commonly recommended after an embryo transfer (ET) carried out during an in vitro fertilization (IVF). This is based on beliefs that supine position and the reduction of physical activity-to the minimum-might prevent the risk of embryo expulsion once is transferred to the uterus. Therefore, we have designed a meta-analysis based exclusively on evidence from published randomized controlled trials (RCTs), in the attempt to analyze the effectiveness of bed rest after an ET to improve the chance for success in vitro fertilization.
Methods: The review protocol was registered in PROSPERO (CRD42019122758), and data extraction started before protocol publication. Five RCTs were included; 499 women were assigned to the intervention group and 503 to the control group.
Results: The analysis of 1002 women did not show any significant change in clinical pregnancy rate between groups [RR 0.86, 95% CI (0.74-1.00), p = 0.06, I2 = 0%]. Likewise, no difference was found in live birth [RR 0.93, 95% CI (0.51-1.69) p = 0.81, I2 = 68%], ongoing pregnancy rate [RR 0.84, 95% CI (0.60-1.20), p = 0.34, I2 = 63%], miscarriage rate [RR 1.08, 95% CI (0.46-2.57), p = 0.86, I2 = 64%], multiple pregnancy rate [RR 0.08, 95% CI (0.50-1.04), p = 0.71, I2 = 0%] or implantation rate [RR 0.90, 95% CI (0.72-1.13), p = 0.38, I2 = 0%]. Subgroup analyses-considering only immediate mobilization or bed rest 24 h-did not show significant differences regarding the outcome.
Conclusion: Our findings showed that immediate mobilization after an ET does not have a negative influence over the success rates of IVF. Therefore, bed rest should not be recommended.
Keywords: Bed rest; Clinical pregnancy rate; Embryo transfer; Miscarriage; Ongoing pregnancy.