If three people, as the late Princess of Wales famously observed, made for a crowded marriage, then it was bound to prove interesting when the High Court settled down to deal with a conglomeration of relationships involving one male couple donating sperm informally, two female couples, assorted friendships, three civil partnerships, two sons, one daughter and a complete absence of formal agreement as to the degree of involvement the sperm donors would have in their respective biological childrens’ lives.

Re G/Re Z arose out of each male having acted as sperm donor to, respectively, one female couple (producing a girl and a boy) and the other female couple (producing a boy). When relations between the men and women deteriorated as a result of disagreement over the amount of involvement the men were having in the children’s lives, the men applied under the Children Act 1989 for permission to make applications for residence and contact.

As a result of the reforms introduced by Part 2 of the Human Fertilisation and Embryology Act 2008, where the woman who is artificially inseminated is in a civil partnership, her civil partner will be the second parent of any children conceived as a result (unless she did not consent). This is the case whether the woman is treated in a licensed clinic or not (compare this situation with that where there is no civil partnership: then the female partner will only become the second parent if treatment took place in a licensed clinic and the "agreed parenthood" conditions apply). The Act also provides that where a woman is treated as the second parent of the child, no man is to be treated as the father of the child "for any purpose".

So, the sperm donors were not the legal fathers of the two children concerned in the application (the two boys) and the mothers argued that their attempts to involve themselves in the lives of their biological children would encroach unduly upon the existing female-led family units. Notwithstanding this, Mr Justice Baker granted leave to both men to apply for contact (but not residence, which he considered a bridge too far) with their biological sons.

The judgment establishes that, when considering whether or not a known donor could apply for orders relating to residence, contact and parental responsibility, the court will take into account factors including the nature of the application, the connection to the child that the applicant has been permitted to establish and the potential for disruption to the child’s life and wellbeing. However, it is equally clear that the court will be mindful of the need to protect the "lesbian de novo family" and their Article 8 rights to a family life.