BACKGROUND The use of immature oocytes is limited to cases where these are the only available oocytes, and they are usually only microinjected with sperm after having undergone maturation in vitro. This study compares the outcome of injection of sperm into metaphase I oocytes immediately after their denudation (MI) performed 2 h after their retrieval, with the outcome of injection of sperm into...

A case is reported of successful in-vitro fertilization (IVF) and pregnancy in a natural cycle after four previously failed attempts with stimulated cycles. The patient began treatment at the age of 36 years and underwent four stimulated IVF cycles, each time with three embryos of good quality transferred. In one attempt, three cryopreserved embryos were transferred in a natural cycle. The pati...

Sperm-egg interaction is one of the most impressive processes in sexual reproduction, and understanding the molecular mechanism is crucial in solving problems in infertility and failed in vitro fertilization. The main purpose of this study is to map the sperm-egg interaction network between cell-surface proteins and perform an interaction analysis on this new network. We built the first protein...

An increasing number of women fail to achieve pregnancy due to either failed fertilization or embryo arrest during preimplantation development. This often results from decreased oocyte quality. Indeed, reduced mitochondrial DNA copy number (mitochondrial DNA deficiency) may disrupt oocyte quality in some women. To overcome mitochondrial DNA deficiency, whilst maintaining genetic identity, we su...

In this study, we analysed the distribution of beta tubulins to detect spindle and cytoplasmic microtubules, alpha acetylated tubulins for sperm microtubules and chromatin configuration in oocytes showing fertilization failure after conventional IVF or intracytoplasmic sperm injection (ICSI). A total of 450 human oocytes that failed to fertilize were studied 20-40 h after IVF or ICSI. In all, 2...

The study was to investigate the effects of oxygen concentration at different levels for culturing pre-compaction embryos on human embryo development competence. A total of 1254 oocytes from 92 patients treated with conventional in vitro fertilization (IVF) were harvested in this study. Oocytes were randomly assigned to the atmospheric (~20%) or low (~5%) oxygen concentration groups on the retr...

Despite the advent of ICSI, cases of total fertilization failure (TFF) often lead to cycle cancellation with limited diagnostic and therapeutic strategies currently available. We report on the case of an infertile couple who failed to conceive after repeated IVF and ICSI. Sperm of the husband were morphologically normal and passed a functional test assessing their ability to activate mouse oocy...

Previous studies relating hormone and cytokine concentrations in follicular fluid to oocyte fertilizability were flawed by the uncertainty about the actual oocyte maturity status at the time of recovery and by the possible contribution of the male factor to failures of conventional in-vitro fertilization. This is the first study in which oocyte maturity was assessed immediately after recovery a...

This prospective study examines the benefits of using natural cycles instead of stimulated cycles in poor responders to in-vitro fertilization (IVF) treatment. Eleven patients in whom puncture was cancelled or who failed to conceive because of a poor response were included in the analysis. The data for natural cycles (n = 16) were compared with data obtained during previous stimulated cycles (n...

Three experiments were conducted using a total of 84 ewes to determine the effects of bilateral or unilateral insertion of intrauterine threads on fertilization rate and unilateral insertion on embryonic survival. In experiment I bilateral insertion of intrauterine threads significantly reduced the proportion of ewes with fertilized ova 3 days after mating. Intrauterine threads inhibited fertil...