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...

Data were obtained from 1,908 pregnancies resulting from bovine embryo transfer procedures. Responses examined included sex ratio, fetal, neonatal and preweaning death losses, birth weight and calving assistance. The sex ratio for 1,751 embryo transfer calves examined was 51.11% males. Cows older than 10 yr that had become repeat breeders produced more (P less than .05) male calves than other d...

Variability in the cultivated germplasm for economic traits such as resistance to rice tungro virus, sheathblight, yellow stem borer, drought and salt tolerance is limited. This necessitated search for the genes in secondary and tertiary gene pool of genus Oryza. Fortunately, wild species are an important reservoir ofuseful genes for resistance to major disease, pest and tolerance t...

Intraspecific and interspecific embryo transfer in domestic South American camelids is developing into a well-established technique. Reports reveal many benefits of using reproductive biotechnologies to allow rapid propagation of alpacas and llamas of high genetic merit (e.g., high fiber quality, preserve color variation). The objective of this review is to provide up-to-date information about ...

BACKGROUND Embryo culture media used for IVF treatment might affect fetal growth and thus birthweight of the newborns. METHODS A retrospective study was conducted in South China using data from 2370 singleton neonates born after IVF/ICSI between 2009 and 2012. Two culture media, i.e., either Vitrolife or SAGE were used as embryo culture media during the study period. Neonates' birthweights we...

background: singleton pregnancy with a live birth beyond 37 weeks of gestation is the ultimate goal of any assisted reproductive technology. however, singletons conceived after art are found to have a poor perinatal outcome in comparison to naturally conceived singletons. it was hypothesized that the outcome of singleton conceived after transfer of two or more embryos may be dependent on the sh...

The present study investigated the effect of embryo transfer on post-implantation development using different fertilization approaches in sibling oocyte procedures. C57BL/6, DBA/2, C3H/HeJ and ICR mice were used at 8-10 weeks of age. Mature oocytes were collected, divided into two groups and fertilized using in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Different numb...

BACKGROUND We wanted to test the hypothesis that using abdominal ultrasound at the time of embryo transfer to guide replacement, improved pregnancy rates by at least 5%. METHODS An RCT in a large assisted conception unit. A pilot study and power calculation suggested that at least 2000 embryo transfers were required to demonstrate a difference of 5%, for a test with 80% power and Type 1 error...

There are numerous studies concerning pregnancy rates in oocyte donation, yet only a handful report the obstetric outcome in such pregnancies. The purpose of this study was to assess factors that influence pregnancy rates, to determine the incidence of complications, and to evaluate obstetric outcome in pregnancies resulting from oocyte donation. This study included 423 oocyte recipients who un...