|
Embryo culture is a component of ''in vitro'' fertilisation where in resultant embryos are allowed to grow for some time in an artificial medium before being inserted into the uterus. ==Duration== The duration of embryo culture can be varied, conferring different stages of embryogenesis at embryo transfer. The main stages at which embryo transfer is performed are cleavage stage (day 2 to 4 after co-incubation) or the blastocyst stage (day 5 or 6 after co-incubation). Embryos which reach the day 3 cell stage can be tested for chromosomal or specific genetic defects prior to possible transfer by preimplantation genetic diagnosis (PGD). Embryo culture until the blastocyst stage confers a significant increase in live birth rate per embryo transfer, but also confers a decreased number of embryos available for transfer and embryo cryopreservation, so the cumulative clinical pregnancy rates are increased with cleavage stage transfer. Transfer day 2 instead of day 3 after fertilization has no differences in live birth rate.〔 Monozygotic twinning is not increased after blastocyst transfer compared with cleavage-stage embryo transfer. There are significantly higher odds of preterm birth (odds ratio 1.3) and congenital anomalies (odds ratio 1.3) among births from embryos cultured until the blastocyst stage compared with cleavage stage.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Embryo culture」の詳細全文を読む スポンサード リンク
|