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...

BACKGROUND Whether extended culture allowing selection of embryos with high development potential has any advantage over cleavage-stage embryo transfer remains a matter of debate. Among the currently unsolved questions, the cumulative delivery rate resulting from fresh and frozen embryo transfers needs to be taken into account in both strategies. The aim of our study was, therefore, to compare ...

Multiple pregnancies lead to complications and induce high costs. The most successful way to decrease multiple pregnancies in IVF is to transfer only one embryo, which might reduce the efficacy of treatment. The objective of this review is to determine which embryo-transfer policy is most cost-effective: elective single-embryo transfer (eSET) or double-embryo transfer (DET). Several databases w...

Although embryo transfer technology has been used commercially in cattle for many years, the inefficiency of oestrus detection, especially in recipients, has limited the widespread application of this technology. The most useful alternative to increase the number of recipients utilised in an embryo transfer program is the use of protocols that allow for embryo transfer without the need for oest...

although the mechanisms under which sex ratio is controlled in nature remain unknown, researchers have attempted to treat sperm in an effort to predetermine the sex of the offspring. the methods of sperm separation that have been repeatedly reported to isolate fractions rich in x- or y-chromosome bearing sperm are serum albumin gradient swim-up and flow cytometry. however, the ability of the se...

The technique of embryo transfer is very crucial and great attention and time should be given to this step. In order to optimize the embryo transfer technique, several precautions should be taken. The first and most important is to avoid the initiation of uterine contractility. This can be achieved by the use of soft catheters, gentle manipulation and by avoiding touching the fundus. Secondly, ...

In human IVF procedures objective and reliable biomarkers of oocyte and embryo quality are needed in order to increase the use of single embryo transfer (SET) and thus prevent multiple pregnancies. During folliculogenesis there is an intense bi-directional communication between oocyte and follicular cells. For this reason gene expression profile of follicular cells could be an important indicat...

In the past decade, assisted reproductive technologies (ART) such as oocyte transfer, intracytoplasmic sperm injection (ICSI), and nuclear transfer (cloning) have become effective enough for clinical use. ART such as oocyte transfer and ICSI allow production of foals from mares that cannot provide an embryo by standard embryo-transfer procedures. For the equine practitioner, application of ART ...

The main variables that affect nidation are related to uterine receptivity, embryo quality and the efficiency of embryo transfer. Embryo transfer is the critical step in assisted reproductive technology; with rigid catheters, contamination with blood, mucus or bacteria, increased contraction waves of the myometrium, and the level of difficulty in introducing the catheter inside the uterine cavi...

Sir, With interest we read the article of Henningsen et al., who compared pregnancy outcomes in singleton pregnancies after ART to singleton pregnancies that were conceived naturally. The authors report a significantly increased risk of stillbirth after ART before a gestational age of 28 weeks. They conclude that in view of the fact that the increased stillbirth risk was observed before 28 week...