The effect of artificial oocyte activation (AOA) with a calcium ionophore on intracytoplasmic morphologically selected sperm injection (IMSI) was examined in patients with histories of repeated failed implantation attempts. Four singleton pregnancies and one twin pregnancy were obtained after embryos transfer (5/14, 35.7%). Therefore, AOA combined with IMSI can be considered an option for cycle...

BACKGROUND Complete fertilization failure after ICSI is a rare event, and it may happen repeatedly even in cases of normal sperm parameters and good ovarian response. In these cycles, alternative ICSI techniques may prove useful. METHODS Our modified ICSI (mICSI) is characterized by aspiration close to the opposite membrane (the region of the mitochondria with a high inner mitochondrial membr...

Free-spawning marine invertebrates that live near shore or in estuaries may experience reduced fertilization success during low-salinity events. Although several studies have documented reproductive failure at reduced salinity in estuarine animals, few have looked at whether developmental failure is due to a failure of fertilization or to a failure of fertilized eggs to cleave. In this study, w...

BACKGROUND The necessity of extracellular Ca2+ for fertilization and early embryonic development in the African clawed frog, Xenopus laevis, is controversial. Ca2+ entry into X. laevis sperm is reportedly required for the acrosome reaction, yet fertilization and embryonic development have been documented to occur in high concentrations of the Ca2+ chelator BAPTA. Here we sought to resolve this ...

Effects of climate change-driven disturbance on lake ecosystems can be subtle; indirect effects include increased nutrient loading that could impact ecosystem function. We designed a low-level fertilization experiment to mimic persistent, disturbances (deeper thaw, greater weathering, or thermokarst failure) delivering nutrients arctic lakes. measured responses pelagic trophic levels over 12 yr...

introduction: the incidence of sperm and oocyte premature chromosome condensation (pcc) in the failed fertilized oocytes that were taken after routine in viro fertilization (ivf) and intracytoplasmic sperm injection (icsi) programs were investigated. materials and methods: in this study, 364 air-dried preparations of failed fertilized oocytes after either ivf or ocsi procedures were analyzed. t...

OBJECTIVE To compare the laboratory outcomes of intracytoplasmic sperm injection (ICSI) and conventional insemination using sibling oocytes in poor prognosis IVF cycles where ICSI is not indicated. METHODS Couples undergoing IVF with following conditions were enrolled: history of more than 3 years of unexplained infertility, history of ≥3 failed intrauterine insemination, leukocytospermia or ...