Embryo TransferWhat is Embryo Transfer?oEmbryo transfer refers to a step in the process of assisted reproduction in which embryos are placed into the uterus of a female with the intent to establish a pregnancy. This technique (which is often used in connection with in vitro fertilization (IVF)) may be used in humans or in animals in which situations the goals may vary.!mbryo transfer ta"es place after eggs have been collected and fertilized in the laboratory. #epending on your situation between one and three of the best quality embryos are selected and then transferred to the woman$s womb. %n embryo must successfully attach itself to the wall of the womb for pregnancy to begin.What is Embryo Transfer?Types of Embryo Transfero In vitrofertilization (IVF) is a process by whichan eggis fertilizedbyspermoutside the body'in vitro((in glass(). The process involves monitoring and stimulating a woman)s ovulatory process removingovum or ova (egg or eggs) from the woman)sovariesand letting sperm fertilize them in a liquid in a laboratory. The fertilized egg (zygote) is cultured for *+, days in a growth medium and is thenimplantedin the same or another woman)suterus with the intention of establishing a successfulpregnancy.Your clinic may recommend IVF if:o -ou have been diagnosed with une.plained infertilityo -our fallopian tubes are bloc"edo /ther techniques such as fertility drugs or intrauterine insemination (I0I) have not been successfulo The male partner has fertility problems but not severe enough to require intra1cytoplasmic sperm in2ection (I34I)Types of Embryo Transfero Intra-cytoplasmic sperm injection (I!I) differs from conventional in vitro fertilization (IVF) in that the embryologist selects a single sperm to be in2ected directly into an egg instead of fertilization ta"ing place in a dish where many sperm are placed near an egg. This procedure is most commonly used to overcome maleinfertility problems although it may also be used where eggs cannot easily be penetrated by sperm and occasionally in addition tosperm donation.Your clinic may recommend I!I if:o -ou have a very low sperm counto 5oor morphology (abnormal shape) or poor motility (not moving normally)o #uring previous attempts at IVF there was failure of fertilizationo -ou need sperm to be collected surgically from the testicles or epididymisHow does embryo transfer work?The e.act procedure for embryo transfer depends on the clinic you choose. % typical procedure may involve the following'!tep "#Two to three days after the eggs are fertilized the best quality embryos are selected to be transferred to your womb.If you have good quality embryos those that are not transferred can be frozen. 4ome clinics may also offer blastocyst transfer where embryos are transferred five to si. days after fertilization.How does embryo transfer work?!tep $#The doctor or nurse doing the embryo transfer inserts a speculum into your vagina. This is the same procedure as a cervical smear test where the speculum is used to "eep your vagina$s wall apart. This is normally a pain1free procedure and usually no sedation is necessary but you may e.perience a little discomfort because you need a full bladder if ultrasound is used.!tep %#It is generally recommended that you lead a gentle lifestyle during the few days after embryo transfer.!tep %bout two wee"s after the embryo transfer you will be given a pregnancy blood test. If it is positive you will have a scan about two wee"s later.Frozen EmbryosWhen can the embryo transferbe performed?o!mbryo transfer can be performed after various durations of embryo culture conferring different stages in embryogenesis. The main stages at which embryo transfer is performed are cleavage stage (day * to 6 after co1incubation) or the blastocyst stage (day 7 or , after co1incubation.o!mbryos who reach the day 8 cell stage can be tested for chromosomal or specific genetic defects prior to possible transfer by preimplantation genetic diagnosis (59#). Transferring at the blastocyst stage confers a significant increase in live birth rate per 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 * instead of day 8 after fertilization has no differences in live birth rate.When can the embryo transferbe performed?o :onozygotic twinning is not increased after blastocyst transfer compared with cleavage1stage embryo transfer.o There is a significantly higher odds of preterm birth (odds ratio ;.8) and congenital anomalies (odds ratio ;.8) among births having reached the blastocyst stage compared with cleavage stage.What are the chances of getting pregnant after embryo transfer?Female fertility diminishes with age so if you are using your own eggs on average the younger you are the higher your chances of success.In the year*