Pregnyl is not made from actual human tissue, at least last I heard.
It's FAR easier to engineer a bacterial system to mass-produce the HCG, then isolate the hormone in large volumes, than it is to collect it from the placenta/urine of pregnant women.
Because it is human chorionic gonadotropin does not mean it is human sourced. A lot of the research work I do involves gene expression vectors by which human or yeast genes are expressed using viral systems (using insect cells as a host) or E.coli DH5alpha which has plasmids containing the gene of interest behind a constitutive promoter.
You can make buckets of proteins which are normally expressed in nanogram quantities.
There is no danger of getting any sort of viral infection from Pregnyl or any other engineered HCG.
-M