Dear Darcy, 

Check these papers out:  I cite:

"equity demands the child's right to know its biological parentage, recognised under Article 7 of the UN Convention on the Rights of the Child, 1989. DNA profiling may clarify the genetic parentage with virtual certainty but with multiple limitations. DNA forensics ascertains the genetic makeup of a child linking putative parents irrespective of any social relationship between them. The right to know biological linkages gained paramount significance in cases like displacement, adoption, child trafficking and variants of cross-genetic in vitro fertilization including complete surrogacy."

Article Surrogacy for the Single, Gay Man

Conference Paper If Anybody Looked, I Was Always There': Recognition and Part...

Article The Pregnancy Experience of Gay Couples Expecting a Child Th...

Article The genetic truth of surrogate parentage

Article Surrogacy: Outcomes for surrogate mothers, children and the ...

Article Conceiving fatherhood: Gay men and Indian surrogate mothers

 Dear Darcy,..

Surrogacy of parents indeed has created lots of confusion in parentage determination. I the light of LGBT rights this may further complicate the traditional approach of parenthood and this area need fresh look in the modern era of constructed pregnancies. It further aggregates the problem in the light of various religions which proscribe the pregnancy out side the valid marriage. Assisted human reproduction especially IVF has potential of crossing borders and bodies and has introduced terms like 'baby shopping', 'reproductive tourism', ''baby editing' etc. I suggest you to read Prof. Marcia. C. Inborn of Yale University who has reflected on the issue in great way. 

Regards....