Influencia de la calidad embrionaria y seminal en el síndrome del embrión evanescente

Abstract

Background The vanishing embryo phenomenon is defined as the spontaneous loss of one or more embryos in a multiple pregnancy without its interruption. The aim of this study was to determine the rate of vanishing embryo syndrome in women with multiple pregnancies conceived by Intracytoplasmic Sperm Injection (ICSI), to analyse the evolution of these pregnancies, and to find a relationship with possible causes, such as embryo and seminal quality. Material and methods A retrospective analysis was performed of 145 multiple pregnancies conceived by ICSI, from January 2004 to December 2008. They were divided in two groups (112 without vanishing syndrome and 33 with any embryo suffering from vanishing syndrome). We then carried out a case-control study in order to compare the neonatal results of single pregnancies with vanishing embryo syndrome. We carried out transvaginal ultrasound monitoring until 12 weeks of gestation. The data were obtained from the centre data base. Results Vanishing embryo syndrome was observed in 22.7% of our patients, with 17.5% of cases being observed in twin pregnancies, and 50% in triple pregnancies. The vanishing embryo rate in multiple pregnancies was significantly lower in the group with two gestational sacs than in the group with three or more gestational sacs ( P < .001). The rate of good quality embryos was significantly higher in the group without vanishing embryos ( P < .001). No differences were observed in terms of age and seminal quality among study groups. Perinatal outcomes of live births were similar in both groups. Conclusion Vanishing embryos rate seems to increase in pregnancies with over two gestational sacs. We observed a relationship between this syndrome and embryo transfer quality.