How many human embryos die between fertilisation and birth under natural conditions? It is widely accepted that natural human embryo mortality is high, particularly during the first weeks after fertilisation, with total prenatal losses of 70% and higher frequently claimed. However, the first external sign of pregnancy occurs two weeks after fertilisation with a missed menstrual period, and esta...

Gametogenesis (spermatogenesis and oogenesis) is accompanied by the acquisition of gender-specific epigenetic marks, such as DNA methylation, histone modifications and regulation by small RNAs, to form highly differentiated, but transcriptionally silent cell-types in preparation for fertilisation. Upon fertilisation, extensive global epigenetic reprogramming takes place to remove the previously...

the objective of the research was to test the effect of iron and aluminium coagulants commonly used for lake re-cultivation, on the pike sperm motility and fertilisation. the coagulants caused changes in the analyzed hydrochemical parameters of the water such as: fe, mg2+, tss, so42- and cl-. selected parameters of sperm motility: mot, vcl, vsl, vap, lin were estimated using casa. the sperm mot...

During the 20 years since the first child was born in Sweden after in vitro fertilisation, clinical policy has changed. During the early 1990s, the clinics performing in vitro fertilisation and the National Board of Health and Welfare agreed to reduce the number of embryos transferred to the uterus during in vitro fertilisation from three to two. Here, we describe the changes in multiple birth ...

One of the few examples of explicit rationing in the National Health Service is provided by in vitro fertilisation. Ofsix purchasing authorities examined three have decided against buying in vitro fertilisation while three have decided in favour. The decisions reflect local factors such as the absence or presence of local providers and the views of the public and health professionals. But in vi...

OBJECTIVE To evaluate the effects of a multifaceted empowerment strategy on the actual use of single embryo transfer after in vitro fertilisation. DESIGN Randomised controlled trial. SETTING Five in vitro fertilisation clinics in the Netherlands. PARTICIPANTS 308 couples (women aged <40) on the waiting list for a first in vitro fertilisation cycle. INTERVENTIONS The multifaceted strateg...

Yield mapping of crops obtained by harvest with a combine equipped with yield metering device and GPS positioning system, has in recent years, become an important tool in crop management. With respect to nitrogen fertilisation, it is now technically possible to change practices from uniform application to differentiated, site-specific application. The presentation introduces and discusses a met...

In this study we evaluated the value of short-time insemination and early rescue intra-cytoplasmic sperm injection (ICSI) in preventing the occurrence of complete fertilisation failure for mild or moderate male infertility patients. A total of 866 couples with borderline semen who underwent in vitro fertilisation treatment in 2010 were included. Regular insemination was performed between Januar...

Fertilisation by intracytoplasmic sperm injection (ICSI), a technique that bypasses the membrane fusion of the gametes, has been widely used to produce offspring in humans and mice. Success with this technique has lent support to the hypothesis that in mammalian fertilisation, a factor from the sperm, the so-called sperm factor, is responsible for oocyte activation and that the fusion process i...