Influences of bed rest time after in vitro fertilization-embryo transfer on pregnancy outcomes

Abstract

Objective To explore the influences of different bed rest time after in vitro fertilization-embryo transfer (IVF-ET) on pregnancy outcomes. Methods From June 2010 to June 2014, a total of 2 262 cycles of 2 262 infertility patients in Center of Reproductive Medicine, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School were selected as research subjects. According to the different bed rest times after embryo transfer, they were divided into 4 groups: group A (755 cycles, left the hospital after 10 minutes of bed rest), group B (526 cycles, left the hospital after 30 minutes of bed rest ), group C (506 cycles, left the hospital after 1 hour of bed rest) and group D (475 cycles, left the hospital after 2 hours of bed rest). Fertility rate, embryo implantation rate, clinical pregnancy rate among 4 groups were compared by statistical methods. Before IVF-ET, all the patients signed the informed consents, and this study was in line with the ethics standards promulgated by the human subjects committee of Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School. Results ①There were no statistically significant differences among 4 groups in the age, infertility duration, the number of retrieved oocytes and soon (P>0.05). ②The fertility rates of group A, B, C and D were 87.4% (6 377/7 293), 87.8% (4 792/5 455), 86.9% (4 306/4 954) and 87.1% (4 036/4 636), respectively. The embryo implantation rates were 49.3% (715/1 450), 49.2% (497/1 010), 48.9% (480/982) and 48.4% (448/926), respectively. The clinical pregnancy rates were 70.6% (533/755), 69.0% (363/526), 70.4% (356/506) and 68.0% (323/475), respectively. There were no statistically significant differences among 4 groups in fertility rate, embryo implantation rate and clinical pregnancy rate (χ2=2.455, P=0.483; χ2=0.221, P=0.974; χ2=1.151, P=0.765). Conclusions To take early ambulation or to stay in bed for a short time after embryo transfer does not affect the pregnancy outcomes of IVF-ET. It is more scientific and reasonable to arrange the need for bed rest and bed rest time individually according to the physical and psychological status of the patients after embryo transfer. Key words: Fertilization in vitro; Embryo transfer; Bed rest; Pregnancy rate; Women