Legal complexities of modern families – transgender parenthood, artificial insemination and parental responsibility
A criticism often levelled at the law surrounding modern parenthood is that it has failed to keep pace with technological change. The law is failing to remain fit for purpose in the modern age and for modern families.
This can lead to practitioners having to find solutions to problems created by unforeseen gaps in the law, effectively making the law with each new case. However, for those who find themselves having to turn to the law to obtain a resolution to a deeply personal issue, it is a distressing and uncertain landscape.
Recent cases FZ v MZ & FZ v Y Council [2025] EWHC 3338 (Fam) and KL v BA (Parental responsibility) [2025] EWHC 102 (Fam) have brought these issues into sharp focus.
FZ v MZ & FZ v Y Council concerned complex questions of legal parenthood, birth registration, and the rights of a transgender man (FZ) who held a Gender Recognition Certificate (GRC). The background is as follows:
- FZ is a transgender man who obtained a GRC in 2021.
- FZ married MZ in 2022.
- FZ and MZ had two children together, both through artificial insemination using a known donor, but not through a licensed UK fertility clinic.
- The first child, DZ, was conceived before the marriage.
- The second child, AZ, was conceived after the marriage.
FZ and MZ registered DZ’s birth at the registry office, relying on FZ’s GRC to register him as the father. However, this was legally incorrect as DZ’s conception occurred outside of a licensed fertility clinic, and MZ and FZ were not married at the time.
The original birth certificate was quashed and FZ was granted a step-parent adoption order, establishing him as DZ’s legal parent. The matter of AZ, however, was more complex, principally due to how the HFEA 2008 and the Gender Recognition Act 2004 (GRA 2004) interact.
AZ was conceived after marriage, so section 35 HFEA 2008 applies, i.e. if the biological mother is married to a man at the time of artificial insemination with donor sperm, and her spouse consents to the treatment, the spouse is treated as the father of the child. However, section 12 GRA 2004 states that a trans person must be recorded on the birth certificate by way of their birth sex.
Deciding that FZ could not be registered as the father on AZ’s birth certificate, the court addressed whether this was a breach of FZ’s Article 8 rights of the European Convention on Human Rights (ECHR) to respect for private and family life; it deemed that there had been no violation of these rights.
As can be seen, the HFEA 2008 provides for same-sex couples to acquire legal parenthood after assisted conception, but this does not specifically extend to transgender individuals due to the GRA 2004. Upon handing down her judgment, Mrs Justice Lieven stated “there is, or may be, a lacuna or inconsistency in the statutory scheme” however it “…was appropriate for the Court to defer to the considered judgment of Parliament in the GRA and the HFEA 2008”.
This bears comparison with the earlier TT v Registrar General of England and Wales and Secretary of State for Health and Social Care, in which TT (a transgender male) gave birth to a child using intrauterine insemination with his own eggs. TT held a GRC and wished to be registered as the child’s father on the birth certificate. When refused, he asked the court to consider if his or his child’s Article 8 rights under the ECHR had been breached. The court held TT was correctly registered as the child’s mother.
Although there are differences in TT’s case and FZ’s, the court in TT held that “there is a material difference between a person’s gender and their status as a parent” and that the biological parental role is distinct from the social/psychological role. Therefore, the term ‘mother’ is separate from legal gender, meaning in law there can be male mothers and female fathers.
Whilst this comment partly reconciles the conflict between the HFEA 2008 and the GRA 2004, it does not resolve the issue for transgender parents who do not want their biological sex to be included on their child’s birth certificate. Seven years on, nothing has yet been resolved.
For clarity on parental responsibility and the registration of the father on a child’s birth certificate, KL v BA [2025] EWHC 102 (Fam) was, until recently, seen as good authority. The case concerned KL, who was registered as the father on the child’s birth certificate, although not married to the mother (BA). It later emerged that KL was not the child’s biological father. When KL and BA separated, the child continued to spend time with the father until the mother stopped contact and sought to have KL’s parental responsibility revoked.
Firstly, the court concluded that where a man is neither the biological nor legal father of a child, they cannot gain parental responsibility by being named on a birth certificate. Nor can a non-biological father acquire parental responsibility through a mistake in birth registration. Registering the birth is simply evidence of parentage, and where an issue arises, it must be dealt with by the court.
With the increased accessibility of genetic testing, it is likely that more cases such as this will arise. KL v BA demonstrates that if there is a dispute over the parental responsibility of a non-biological father mistakenly recorded on a birth certificate, they are deemed never to have held parental responsibility. However, the appeal in this case was heard in November last year, so there is the possibility that clarity may be lost.
Uncertainty in the law of England and Wales is nothing new. Nor are societal and technological advances – indeed, the past century bore witness to the most rapid changes the UK has experienced. A growing population, increasing demands on parliamentary time, and an overwhelmed court system combine to heighten uncertainty. Many families are faced with legally unclear questions, and lengthy and stressful court proceedings. Providing an answer to this situation is beyond the scope of this article, but one must press for greater clarity and guidance for individuals who fall between legal gaps.
Jessica's article was published in The Law Society Gazette, 30 January 2026, and can be found here.
