At common law, the husband of a married woman is presumed to be the genetic father of any child that she bears (pater est quem nuptiae demonstrant), and is therefore automatically treated as the child’s legal father from birth. This pre­sumption was, however, always rebuttable by proof that the mother’s husband could not be the child’s genetic father. Before blood tests were available, the sort of evidence that might displace the presumption would be that the husband was sterile or impotent, or that he had been extra quatuor maria (beyond the four seas of England) at the time of conception. While the presumption of paternity within marriage usually simply confirms the genetic father’s identity, at times it results in a legal fiction. A child’s mother and ‘father’ may both know that another man is the true biological father, but the presumption enables them to conceal the extra-marital conception. This common-law rule works, therefore, not to pro­mote truth about a child’s genetic origins, but rather to safeguard the traditional family unit.

Since the 1940s, blood tests have been able to assist in identifying the child’s genetic father. Until fairly recently, blood tests could only rule out a man’s pater­nity. A man who shared the child’s blood group might be her father, but so might any other man with the same blood group. Only if a man’s blood group revealed that he could not have fathered this child was decisive evidence available that he could not be her father. Over the last twenty years, DNA fingerprinting has enabled paternity to be proved with a degree of accuracy which now comes very close to complete certainty. Under s 20(1) of the Family Law Reform Act 1969, as amended, the court may ‘give a direction for the use of scientific tests to ascertain whether such tests show that a party to the proceedings is or is not the father or mother of that person’. Inferences are drawn from a putative parent’s refusal to be tested.[193] The purpose of a s 20 direction is therefore now to establish paternity, rather than to exclude it as a possibility.[194] In the past, the courts were sometimes persuaded that blood tests to establish the child’s paternity might not be in her best interests, because the results might disrupt the stability of the child’s family unit.[195] More recently, the courts have increasingly insisted that there could be very few cases where it would be in the child’s best interests for the truth about her paternity to be suppressed.[196]

Genetics as the test for paternity is, however, routinely trumped by intention following donor insemination. When treatment is provided in licensed clinics, the sperm donor will have signed a consent form agreeing to waive his right to be recognised as the father of any children conceived using his gametes. Donation is then conditional upon the donor’s clearly expressed intention not to become a father. If the woman being treated in a licensed clinic with donated sperm is married, the presumption is that her husband has agreed to be treated as the father of any child that may be born as a result of the treatment.[197] He can avoid being recognised as the child’s legal father only if he can establish that he did not consent to the treatment received by his wife. If the woman is unmarried, her heterosexual partner will be the legal father of any child that may be born, pro­vided that the couple were treated ‘together’. On a literal interpretation, this latter provision is misleading because the male partner will not have received any treatment himself. Instead, what has to be demonstrated is that ‘the doctor was responding to a request for… treatment made by the woman and the man as a couple’.9

Despite the statute’s rather ambiguous wording, the purpose of this rule is clear: if the clinic is aware of the unmarried man’s intention to become the father of any child born following treatment, the law will recognise him as the child’s legal father. Because it is routine to demand that both husbands and unmarried male partners sign consent forms agreeing to be treated as the father of any child who might be born following treatment, there is usually decisive proof of intent. As a result, disputes about paternity following fertility treatment are uncommon, although, as demonstrated by Re D (a child)10 and Leeds Teaching Hospital NHS Trust v A,11 not unprecedented.

In Re D (a child), a woman sought treatment with donated sperm after she and her partner, with whom she had previously undergone treatment, had split up. She did not tell the clinic that the relationship was over, and as a result the clinic relied upon the earlier consent forms, which had been signed by her and her ex-partner. The House of Lords held that whether a couple were being ‘treated together’ under s 28(3) should be judged at the time of embryo transfer or insemination, and not when the couple were first accepted for treatment. Hence, in this case, the ex-partner was not being ‘treated together’ with the child’s mother at the relevant time, so he could not be recognised as the child’s legal father. A different sort of dispute arose in Leeds Teaching Hospital NHS Trust v A, where Mr B’s sperm was used to fertilise Mrs A’s eggs by mistake. Mr A had consented to the use of his own sperm to fertilise his wife’s eggs, and not to the treatment which his wife actually received, and he was therefore unable to acquire paternity under s 28(2). So, while intention can trump genetic fatherhood under the 1990 Act, this will be possible only if the facts fit squarely within the terms of s 28.

Intention is also only able to trump genetic fatherhood if the sperm has been provided in accordance with the consent requirements laid out in both the Human Fertilisation and Embryology Act 199012 and the Human Fertilisation and Embryology Authority’s Code of Practice.13 If these conditions are not met – for example, if a woman inseminates herself at home with sperm obtained through a private arrangement or purchased over the internet – genetic paternity takes prior­ity over intention. Should this woman be married, her husband will be treated as the child’s father, although this common-law presumption might be trumped by genetic tests which identify the sperm donor. If she registers a different man – her unmarried partner, for example – as the child’s father, there is again a presumption of his paternity which could be rebutted by genetic evidence. Once identified, the sperm donor would be under a duty to maintain his child throughout minority.

Following a surrogacy arrangement with a married woman, the child’s legal father will initially be the surrogate mother’s husband, who is neither the intended [198] [199] [200] [201] [202] nor the genetic father, but acquires his paternity through the common-law pre­sumption of legitimacy within marriage. This might subsequently be rebutted by genetic tests that reveal him to be unrelated to the child. And fatherhood can be formally transferred through either adoption or the special procedure introduced by s 30 of the Human Fertilisation and Embryology Act 1990. Nevertheless, from the moment of the child’s birth, a man who did not instigate the child’s concep­tion, who is not genetically related to the child, and who usually has no desire or intention to play any part in the child’s life will have the right to take decisions about her upbringing, and will be obliged to maintain the child. Conversely, the genetic and intended father will initially bear no responsibility for ‘his’ child.

Because neither adoption nor the s 30 procedure is straightforward, not all surrogacy arrangements culminate in the formal transfer of legal parenthood. For obvious reasons, it is impossible to tell how many unofficial transfers of children take place each year. Worryingly, however, the Brazier Report concluded that ‘a substantial proportion of commissioning couples are failing to apply to the courts to become the legal parents of the child’.[203] In such situations, the surrogate mother’s husband (if she has one) remains the legal father, and the man who is bringing up the child may be a legal stranger to ‘his’ child.

A compelling illustration of the illogicality of the UK’s rules on paternity following surrogacy is provided by applying them to the infamous American case In re Marriage of Buzzanca.[204] In his divorce petition, John Buzzanca asserted that his marriage to Luanne Buzzanca had been childless. Luanne Buzzanca responded by claiming that a surrogate mother (SM) was expecting the couple’s first child. Jaycee Buzzanca, who was born six days later, had been conceived using sperm and eggs from anonymous donors (let us call the sperm donor SD and the egg donor ED). The surrogate and her husband (SM and SH) did not seek to become Jaycee’s parents. The question for the court was a complex one. Out of the three plausible candidates for fatherhood (John Buzzanca, SD, SH) and the three possible mothers (Luanne Buzzanca, ED and SM), who were Jaycee’s legal parents?

At first instance, the trial judge reached the rather surprising conclusion that, despite this surfeit of possible mothers and fathers, none could be considered Jaycee’s legal parents and Jaycee must be judged to be a legal orphan. This was reversed on appeal, when the court held that because Mr and Mrs Buzzanca had jointly initiated Jaycee’s conception, they were her legal parents and they were both therefore under a duty to contribute to her support. As a matter of justice, this seems right. John Buzzanca had deliberately instigated Jaycee’s unconventional conception, and it would seem iniquitous for the law to allow him to shrug off any legal responsibility for the resulting child. John Buzzanca is Jaycee’s father because without the Buzzancas’ decision to become parents through this bizarre arrangement, Jaycee would never have been born. Identifying the surrogate mother’s husband as Jaycee’s father (as English law would have done) would absolve John Buzzanca of his responsibility for the life he deliberately created, and instead pass legal responsibility for Jaycee’s well-being for the next 18 years to a man who was not genetically related to her and who never intended or wanted to become her father.

So we can see that, outside of the paradigm case, the test for legal fatherhood varies according to the circumstances. A genetic link will usually – though not always – determine fatherhood in cases of disputed paternity, where the mother was having sexual intercourse with two men at the time of conception. If a child is conceived using donated sperm, intention will trump the genetic link, provided that insemination took place in a licensed clinic. But if the sperm donation was accomplished informally, genetic relatedness will be decisive. Following a surro­gate birth, it is the man’s relationship with the child’s mother that normally determines the identity of the child’s father. Given this hotchpotch of competing presumptions and hierarchies, the identity of a child’s legal father is patently not a self-evident question of fact.