Using strips of ovarian tissue removed in a biopsy, it represents an advance on IVF (in vitro fertilisation), where a mature egg is fused with a sperm

Using strips of ovarian tissue removed in a biopsy, it represents an advance on IVF (in vitro fertilisation), where a mature egg is fused with a sperm in the lab and the fertilised embryo is implanted. Eggs aren't frozen, but it still sounds like a painful and expensive process.