unconventionally conceived = conceived through IVF, or another method which isn't a natural man + woman + in-body conception + implantation scheme.

i.e. there is some intervention which changes the path, location, constituency, existence, or selection of the sperm or egg such as filtering sperm, artificially selecting sperm, temporarily removing the egg or fetus, exposing either of them to foreign agents for genetic/health purposes, or similar divergence from the conventional method with significant effects.

Judging timespan: if such a condition holds for net children born over at least 6 months before the judging date.