A comparison of pregnancy outcomes between day 3 and day 5/6 embryo transfers: does day of embryo transfer really make a difference?

Abstract

Purpose To determine if day of embryo transfer (ET) affects gestational age (GA) and/or birth weight (BW) at a single university fertility center that primarily performs day 5/6 ET. Methods Retrospective cohort study of 2392 singleton live births resulting from IVF/ICSI at a single large university fertility center from 2003 to 2012. Patients were stratified by day 3 or day 5/6 ET. Outcome variables included patient age, gravidity, prior miscarriages, prior assisted reproduction technology cycles, number of embryos transferred, number of single ET, infertility diagnosis, neonatal sex, GA at birth, and BW. Subanalyses were performed on subgroups of preterm infants. A comparison was made between the study data and the Society of Assisted Reproductive Technologies (SART) published data. Results There was no difference in GA at birth (39±2.1 weeks for day 3 ET, 39±1.9 weeks for day 5/6 ET) or BW between ET groups (3308±568 g for day 3 ET, 3268±543 g for day 5/6 ET). There was also no difference in the number of preterm deliveries (8.5 % for day 3 ET vs. 10.8 % for day 5/6 ET). The day 5/6 ET study data had significantly fewer pre-term deliveries than the SART day 5/6 ET data. Conclusion In contrast to published SART data, GA and BW were not influenced by day of ET. Data may be more uniform at a single institution. Day 5/6 ET continues to offer improved pregnancy rates without compromising birth outcomes.

Influence of cryopreservation on perinatal outcome after blastocyst‐ vs cleavage‐stage embryo transfer: systematic review and meta‐analysis

“…The incidence of very preterm birth before 32 weeks was assessed in eight studies (blastocyst stage, n = 60 488; cleavage stage, n = 86 500). The overall effect size and subgroup analysis of frozen only and fresh plus frozen cycles did not reveal a significant difference between blastocyst‐ and cleavage‐stage embryo transfer with respect to this outcome (Figure ).…”

“…Since the first reports on the technique were published, extended embryo culture has become widespread in assisted reproductive technology. Compared with traditional cleavage‐stage embryo transfer, this procedure results in a sort of ‘natural selection’ of the most viable embryos, analagous to the usual process during spontaneous conception.…”

Effect of mesenchymal stem cells and mouse embryonic fibroblasts on the development of preimplantation mouse embryos

“…The hatching process is critical for embryonic implantation and has been associated with subsequent viable pregnancy, whereas delayed implantation has been associated with a high incidence of abortion (Hammadeh et al 2011). In the clinic, embryos can be transferred within 2–5 days after initial cultivation (Maxwell et al 2015; Sunderam et al 2014), thus the positive effect of shorter-term coculture with MSC is quite relevant.…”

The impact of paternal factors on cleavage stage and blastocyst development analyzed by time-lapse imaging—a retrospective observational study

“…Besides the assumed higher costs and increase in the laboratory workload, PEC is often blamed to be associated with increased risks of congenital malformations, low birth weight, or pre-term birth [6]. However, recently published studies do not support these findings [7,8]. Moreover, the fear of having to cancel transfer due to the lack of blastocyst development, as it is sometimes the case e.g.…”