IVF

[|Forming an Embryo activity.pdf]

Teacher background information Embryonic stem cells are derived from the inner cell mass of a blastocyst. A blastocyst is a 5—7 day old embryo. To make an embryo, a sperm must fertilise an egg. In the first few days after fertilisation the cells inside the developing embryo divide; from one, two, four, six cells etc. Once the cells become too numerous to count, and the embryo begins to resemble a soccer ball, the embryo is called a morula (about day 4—6). The morula begins to hollow out at one end. The embryo is now a blastocyst (about day 5—7). Inside the blastocyst there are two regions: the inner cell mass (which develops into the baby) and the trophectoderm (which becomes the placenta). The inner cell mass is where the embryonic stem cells can be harvested from. All of the abovementioned process occurs in the laboratory. Only embryos donated following the completion of a couples’ IVF treatment can be used to make embryonic stem cells. In Australia scientists wanting to make embryonic stem cells need to have a license.

[|How IVF Works.pdf] Effectiveness of IVF The effectiveness of IVF treatments in terms of live births has steadily increased in response to scientific advances (e.g. in the 1990 the pregnancy rate per embryo transferred was 15%, while by 2008 it had increased to 35%, across the board, with much higher pregnancy rates in certain subgroups). Across all age groups the cumulative proportion who achieve pregnancy is 20.7% after one treatment cycle, around one half after three treatment cycles, and approximately two thirds after six treatment cycles. Only one in 200 couples continue with IVF after six treatment cycles. The risk of complications (e.g. multiple pregnancies) has also decreased significantly, a result of a move towards implanting fewer embryos per cycles (e.g. in Australia guidelines recommend the implantation of 1-2 embryos, except in rare cases).

What are Stem Cells
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http://www.visembryo.com/baby/index.html
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