Day 3 time lapse selection is beneficial for the patients with no good-quality embryos

We aimed to evaluate whether or not time lapse selection was beneficial for the cleavage-stage embryo transfers. The study included 838 infertile women with good ovarian reserve (obtaining more than 8 oocytes) from January 2018 to August 2019. Based on the transferred embryos with different grades (grade I, II and III), the patients were divided into day 3 selection with conventional morphology (CM) and day 3 selection with time lapse (TL) groups. For the grade I and II embryos, we observed that CM and TL had similar implantation, clinical pregnancy and ongoing pregnancy (p > .05) rates. For the grade III embryos, we observed that CM group showed slightly lower implantation (36.74 versus 41.03%, p = .261) and clinical pregnancy (56.82 versus 64.10%, p = .182) rates than TL group. CM group showed significantly lower ongoing pregnancy (47.35 versus 59.83%, p = .025) rate than TL group. And we observed that CM group had significantly higher blastulation (38.93 versus 26.61%, p = .019) rate than TL group. We concluded that TL selection was beneficial to the patients with no good-quality embryos in the first cleavage-stage embryo transfers.