BACKGROUND A scoring system has been developed to determine preimplantation embryo quality, and used to select embryos for transfer into the uterus of patients. METHODS AND RESULTS The system was used to study early embryo development and to test whether these scores alone can accurately predict IVF outcome. Following zygote and embryo scores through early development, the data showed that a ...

Despite the highest historical live birth success rates for couples undergoing in vitro fertilization (IVF), there has been an epidemic of iatrogenic twin and higher order gestation conceived from this treatment. Continued improvement in cryopreservation techniques have allowed preservation of supernumerary embryos for use in future cycles, and refinements in culture systems and embryo selectio...

Culture of bovine embryos with insulin-like growth factor-1 (IGF-1) can improve development to the blastocyst stage and embryo survival following transfer to heat-stressed, lactating dairy cows. Two experiments were conducted to determine whether IGF-1 could improve embryo survival and development at Day 14 after ovulation. In Experiment 1, non-lactating Holstein cows (n=58) were selected as re...

OBJECTIVE To assess the value of routine screening of nuclear status of day-2 four-cell preembryos for single embryo transfer (SET) in predicting implantation. DESIGN Retrospective analysis. SETTING Private IVF unit. PATIENT(S) A total of 1,985 fresh embryo transfers on day 2 or day 3 were performed from January 2002 to November 2004. In 1,295 (65.2%) of these transfers, SET was performed...

STUDY QUESTION Are all twin births following single embryo transfer (SET) monozygotic? SUMMARY ANSWER Between 1 in 10 and in 1 in 5 twins born after SET are the result of a concurrent natural conception. WHAT IS KNOWN ALREADY The twinning rate after SET is higher than following natural conception. Most studies of twins following SET have incorrectly assumed monozygosity or have not been abl...

INTRODUCTION In several clinics, elective single-embryo transfer (eSET) is applied in a selected group of patients based on age and the availability of a good-quality embryo. Whether or not eSET can be applied irrespective of the presence of a good-quality embryo in the first cycle, to further reduce the twin pregnancy rate, remains to be elucidated. METHODS In patients <38 years two transfer...

Embryo transfer offers great advantages to South American camelid farmers to reach their breeding goals but the technology still plays a relatively minor role in comparison to other domestic farm animals like cattle. The aim of the present study was to analyse a data set of 5547 single or multiple ovulation embryo transfers performed in commercial alpaca farms in Australia to determine the fact...

STUDY QUESTION Does the quality of a single transferred embryo have an effect on the pregnancy outcome? SUMMARY ANSWER After adjusting for confounding maternal variables, poor embryo quality was not associated with adverse obstetric or perinatal outcome in this small pilot study. WHAT IS ALREADY KNOWN Embryo quality is a major predictor of the success of in vitro fertilization treatment and...

This multicenter cohort study on embryo assessment and outcome data from 11,744 IVF/ICSI cycles with 104,830 oocytes and 42,074 embryos, presents the effect of women's age on oocyte, zygote, embryo morphology and cleavage parameters, as well as cycle outcome measures corrected for confounding factors as center, partner's age and referral diagnosis. Cycle outcome data confirmed the well-known ef...

Success rates with in vitro fertilization (IVF) continue to improve as we gain insight into optimal culture conditions for gametes and embryos. New procedures such as in vitro egg maturation, preimplantation genetic testing, single embryo transfer, and oocyte freezing hold the promise of reducing the cost, inconvenience, and risks of IVF, as well as preserving future fertility. We provide an ov...