For most of legal history, parenthood was a question with obvious answers. The woman who gave birth was the mother. The mother's husband was presumed to be the father. Roman law captured it in a phrase: mater semper certa est—the mother is always certain.

Assisted reproductive technology has quietly dismantled that certainty. A child can now have five potential parents: an egg donor, a sperm donor, a gestational surrogate, and two intended parents commissioning the arrangement. Each contributes something different to the child's existence, and legal systems must decide which contributions create parenthood.

The answers vary dramatically. France criminalises surrogacy while California enforces surrogacy contracts. Sweden guarantees donor-conceived children the right to know their genetic origins; other jurisdictions protect donor anonymity absolutely. These divergences are not accidents. They reveal deep disagreements about what parenthood fundamentally is—biological fact, social role, or contractual arrangement.

When a child is born from a donated egg carried by a surrogate for intended parents, three women have plausible claims to motherhood. Legal systems resolve this triangular problem by choosing which relationship they consider foundational.

The gestational primacy approach, dominant across continental Europe, treats the woman who gives birth as the legal mother regardless of genetic connection. German and French law codify this position directly. The reasoning draws on the physical and emotional bond of pregnancy, the certainty of identifying the birth mother, and a wariness of commodifying reproduction through contract.

The intent-based approach, developed in California's Johnson v. Calvert (1993) and adopted in various forms across common law jurisdictions, asks who initiated the reproductive project and intended to raise the child. Genetic and gestational contributions become inputs to a parenting plan rather than automatic sources of legal status.

A third path, taken in the United Kingdom, splits the difference: the birth mother is legal mother at birth, but parenthood transfers to intended parents through a post-birth parental order. This staged approach preserves gestational primacy as a default while accommodating intended parenthood through regulated process rather than private contract.

Takeaway

Every legal system must choose a tiebreaker when biology fragments. That choice reveals whether the system trusts contracts, bodies, or bureaucratic supervision to define family.

Surrogacy law falls along a spectrum from absolute prohibition to full contractual enforcement, with most jurisdictions occupying uncomfortable middle ground.

At the prohibition end, France, Germany, and Italy treat surrogacy contracts as void and, in some cases, criminal. The justification blends dignity concerns—that women's reproductive labour should not be commodified—with children's rights arguments against being subject to transfer agreements. Yet these prohibitions do not prevent citizens from travelling abroad, creating recognition problems when families return home with foreign-born children.

The tolerance model, seen in the UK and parts of Australia, permits altruistic surrogacy while banning commercial arrangements and refusing to enforce any surrogacy contract as such. Parental status transfers through judicial process, and the surrogate retains the right to change her mind until that process completes. This preserves the surrogate's autonomy at the cost of certainty for intended parents.

The regulation model, exemplified by several US states and Ukraine before recent disruptions, treats surrogacy as a legitimate contract subject to specific safeguards: legal representation for surrogates, medical and psychological screening, and pre-birth parentage orders. The wager is that clear rules produce better outcomes than prohibition that merely displaces the practice offshore.

Takeaway

Prohibiting a practice does not eliminate it; it exports it. The real question is not whether surrogacy will happen, but who bears the legal and human costs of pretending it does not.

For decades, gamete donation operated on a promise of anonymity. Donors gave genetic material with assurance that no future claim would reach them; recipients received it without the complication of a third biological party. That equilibrium is collapsing.

Sweden began the shift in 1985 by granting donor-conceived children the right, at maturity, to learn their donor's identity. The United Kingdom, Netherlands, Norway, Finland, Germany, and several Australian states have followed. The underlying principle draws on Article 8 of the European Convention on Human Rights: identity is a protected interest, and knowledge of one's origins forms part of that identity.

Other jurisdictions maintain anonymity as the default. France permitted anonymous donation until 2021 reforms; Spain and much of the United States still do. The justification centres on donor supply—removing anonymity typically reduces donation rates—and on the interests of recipient parents who prefer clean legal boundaries.

Genetic testing has rendered the debate partly academic. Consumer DNA databases now allow donor-conceived people to identify biological relatives without any legal right to information. The law is racing to catch up with a technological reality where anonymity cannot actually be delivered, only formally promised.

Takeaway

Rights that depend on information asymmetry rarely survive contact with new technology. When secrecy becomes technically impossible, legal frameworks must choose between honest transparency and hollow promises.

The variety in reproductive parenthood law is not a temporary muddle awaiting harmonisation. It reflects genuine disagreement about whether parenthood is rooted in biology, gestation, intention, or social recognition—and about the proper role of contract in constituting family.

What emerges from comparison is that no legal system has solved the underlying problem. Each has traded certain difficulties for others. Prohibition displaces practice; contract enforcement raises commodification concerns; gestational primacy strands intended parents; anonymity crumbles under DNA testing.

The useful question is not which system is correct, but which trade-offs a given society finds tolerable given its values and its citizens' actual behaviour. Legal design here is less about finding truth than about choosing which discomforts to live with.