the aim of this study was to analyze the incidence of stage of embryonic development, embryo quality and the time of transfer on pregnancy rate in embryo transfer program timed. we were worked a total of 23holsteincowsasembryo donors, super-ovulated with gonadotropin of pregnant mare serum (pmsg) (2500 3000ui).69 cows were used as recipients of holstein dairy heifers with an age of20 months and...

BACKGROUND Single blastocyst transfer has the advantage of maximizing the fresh single pregnancy rate. However, in patients with a low number of good quality embryos on day 3, it remains unclear whether immediate embryo transfer or further embryo culture with blastocyst transfer is the most preferable option. METHODS A retrospective cohort study was carried out in which the outcome of 590 fre...

BACKGROUND Single embryo transfers (SETs) require the most viable embryo from a cohort to be selected. Day 4 embryos may provide a selection advantage similar to blastocyst transfer as embryos are replaced post-embryonic genome activation and into the uterus where they would normally reside. However, there is currently no adequate morphological system to assess Day 4 embryos. Therefore, we deve...

During spring, summer and winter seasons, Sistani donor cows, with normal reproductive status, were superovulated and embryos were recovered non-surgically on day 7. Grade A blastocyst embryos were either transferred fresh (spring) or frozen (summer and winter). Recovered embryos during summer and winter were exposed to glycerol and frozen using conventional method. During spring season, recipi...

Heterotopic pregnancy is a rare and life-threatening condition which is defined as coexistent intrauterine and ectopic gestation. The risk of ectopic and heterotopic pregnancy is increasing due to the increased risk of multiple pregnancies with the aid of assisted reproductive technologies. However, it hardly happens in the setting of single embryo transfer, since single embryo transfer signifi...

This paper provides a concise review of single embryo transfer (SET) in cycles using fresh embryos as well as in cycles using frozen-thawed embryos. Relevant studies were identified by a computerized search in PubMed for the period 1995-2004. The pregnancy rates, delivery rates and multiple pregnancy/birth rates were evaluated after fresh or frozen embryo transfer as well as cumulative delivery...

IVF has been described as one the medical breakthroughs of the 20 th Century. Over 5 million children have been born using the methods first developed by Robert Edwards who died last year. However there is continuing concern about some of the outcomes of IVF treatment (Kamphuis et al., 2014), particularly the high number of multiple births, a problem which became apparent only a few years after...