Children can't consent to being born, what parents they get, or any crucial early decisions in their life.
My point is that in cases where consent is impossible like for unborn children, the bar is much higher on what kind of experiment could be considered ethical. There must be a clear potential benefit for the child and an acceptable risk compared to that benefit. This experiment fails on both.
(wiki at least also disagrees with you and said the mothers were HIV negative, so plain old in vitro fertilization would have been all that was actually needed)