Testing at five to six days. It is possible that instead of removing and testing one or two cells from a two â three day old embryo, some centres may allow the embryo to develop to five - six days, when there are 100-150 cells.
Long-term use of large amounts of vitamin A might cause serious side effects including fatigue, irritability, mental changes, anorexia, stomach discomfort, nausea, vomiting, mild fever, excessive sweating, and many other side effects.
Mild forms of vitamin A deficiency may cause no symptoms. However, there may still be an increased risk of developing respiratory infections and gastroenteritis, and delayed growth and bone development. There is also a risk of infertility secondary to impaired spermatogenesis, and an increased risk of miscarriage.