A million test tube babies would not have been born without the in vitro fertilization technique introduced in 1978.
Fletcher has advocated for embryonic stem cell research using embryos that would otherwise be discarded from in-vitro fertilization techniques.
"Even the highly perfected in vitro fertilization technique can lead to painful surprises," said the influential Catholic newspaper de Volkskrant.
In vitro fertilization (IVF) techniques are more likely to create dizygotic twins.
On the Discovery Channel series, "Assignment Discovery," new fertilization techniques are explained.
It is from here that many of the breakthroughs in in-vitro fertilization techniques have come.
"Particularly in-vitro fertilization techniques."
And emerging studies of embryos that have been conceived through in vitro fertilization techniques indicate that more males are actually conceived as well.
Opinions about fertilizers and fertilization techniques vary widely among practitioners.