Are you my Mummy?

Without words to mean what we say, how do we say what we mean? In her last post, our guest blogger Rebecca Bollard discussed new reproductive technologies that create the space for ‘three-parent babies’. In this post, she talks about the linguistic gymnastics required to clearly convey what the notion of three-parent babies might mean.

The word ‘mother’ is typically used to refer to a person on whom the biological, legal, and social aspects of parenting rest.  Adoption splits the biological from the social and legal aspects. Egg and sperm donations open up such divides too. Divorce and remarriage can split social and legal parenthood from each other while surrogacy adds another layer of complexity by splitting the biological from the gestational. But now pronuclear transfer (PNT) and maternal spindle transfer (MST) offer ways to further divide the biological down into nuclear DNA and mtDNA donors.

So now the word ‘mother’ has five components – social mother, legal mother, gestational carrier, mtDNA donor, and nuclear DNA donor. Some of these are complex concepts that can barely be conveyed in easily understood plain English words. So, in addition to understanding the relatively complex science behind modern reproductive technology, the public must also grapple with concepts that have no clear semantic expression.

The term ‘mother’ also carries a load of normative values and social connotations, not easily defined. We have long been aware that words are not value neutral. When I write ‘gestational surrogate’, I mean the women who carries a foetus and then gives birth to the baby. This woman is generally the legal mother until adoption procedures are completed. That relationship is considerably more complex than the almost mechanical one suggested by the technical terms ‘gestational surrogate’ and ‘gestational carrier’.

So how do we conduct public debates on issues where there are no words to convey what we are talking about? And can we deal with a situation where words are not neutral descriptors of a common concept, but rather value-laden parts of a broader discourse?

Let us know what you think – in plain English, if possible.

Too many parents spoil the child?

When does a genetic donor become a biological parent and how many biological parents are too many? In this post, our guest blogger, REBECCA BOLLARD, looks at the recent technological developments around the possibility of three-parent babies.

In human fertilisation an egg cell is fertilised by a sperm cell, and each has 23 chromosomes. The fertilised cell has 46 chromosomes (the standard number for a human) and develops into an embryo. Chromosomes are made of DNA and exist in an area of the cell called the nucleus, and contain genes. This is what most people think of when talking about DNA – half comes from each biological parent and combines to form a new person. Every person has two biological parents no matter how complicated the legal or social arrangements may be.

This is, however, not quite the full story. Human cells also contain mitochondria, tiny organelles responsible for making a specific chemical that the cells need to function. Human mitochondria contain a small amount of DNA (often called mitochondrial DNA or mtDNA) in the form of a single chromosome. This chromosome is inherited exclusively from the egg cell and therefore the biological mother. mtDNA consists mostly of genes devoted to the maintenance and running of the mitochondria. Defects in these genes can lead to a range of serious diseases, including a range of incurable heart and muscle problems.

Several technologies may overcome mitochondrial disease. Pronuclear transfer (PNT) and maternal spindle transfer (MST) both allow the nucleus of the mother’s egg to be placed inside the egg from a woman with no mitochondrial issues. Thus, the resulting embryo would have three genetic donors – the man who supplied the sperm, the woman who supplied the egg nucleus, and the woman who supplied the egg and therefore the mtDNA. The first two of these would have supplied most, but certainly not all, of the DNA in the embryo (and resulting person). So, perhaps that person would have three genetic parents?

These techniques could also be used in other circumstances, such as where an intending mother has no eggs or has gone through menopause. Scientists believe they can take a cell from elsewhere in a woman’s body and halve the chromosomes using electricity. This cell could then be used with the egg cell (and mtDNA) of another woman.

The UK Human Fertilisation Embryology Authority (HFEA) recently began a consultation on whether such techniques could be used to help the 1 in 200 children born every year in the UK with mitochondrial diseases. This has led to much discussion in the press, including in the Daily Mail and in The Guardian. This follows earlier works by the Nuffield Council on Bioethics that such techniques would be ethical once proved safe and efficient.

Bioethics professor John Harris argues that mtDNA donors would not be genetic parents as “DNA contained in the donated mitochondria comprises much less than 1% of the total genetic contribution and does not transmit any of the traits that confer the usual family resemblances and distinctive personal features... No identity-conferring features are transmitted by the mitochondria”. He then goes on to argue that he would be more upset at having a mitochondrial disease than “having some third-party DNA in my genome”.

So, when does a genetic donor become a biological parent? The two people donating nuclear DNA are obvious candidates, but what about mtDNA donors? What about gestational surrogates, particularly as the evidence builds that gestation is not a simple relationship (see e.g. the research article by Chen et al in Plos One)? Does it matter, when the biological, social, and legal aspects of parenthood are split more than ever?

Should the number of parents in technology-driven reproduction matter? Or is it irrelevant when we’re talking about serious and otherwise incurable disease?