Hi there,
I was actually in contact with someone from the clinic in Zlin about a year ago, and they do not officially
do PGD for family balancing but they sort of indicated that if you do PGD you know
the gender of the embies from that procedure anyway (from wanting good egg quality) and that from
there a couple could decide what embies to use, i.e discard the "wrong" gender or give them away.
However I am not sure what would happen if somebody found out about this in Czech rep
as I do think gender selection is banned in that country so just be careful. Just my 
Krissymum