My wife gave birth to our three children at home during what seems now to have been a brief period of years when home births were coming back into fashion again. Since then, 50 years ago, the pendulum has been swinging strongly back into hospital deliveries. . . . Since then also, according to research cited by Dr Michel Odent, a French doctor speaking at the Hay Literature Festival this year, women giving birth in recent years have been taking two and half times longer in the first stage of labour.
In his new book, Do We Need Midwives? Dr Odent is arguing that childbirth is becoming so medicalised that women may lose the ability to give birth unaided. Increasingly, the drip-feed use of a synthetic form of oxytocin during labour may cause a gradual evolutionary loss in women’s ability to produce the natural hormone. He is also critical of the increasing use of caesarean sections, this procedure now being used in more than a quarter of births in England. This also will cause evolutionary losses, he believes.
As a gynacological expert he may be right. What interest me me, however, is what is already happening at the initial fertilization end of the children business — IVF treatment — and also what might happen increasingly in the future as the cost of complete DNA sequencing is reduced to levels that will be affordable by any young woman. Given that almost all normal young women want children sooner or later — and healthy ones, too — I think that, gradually, though not too long hence, all young women, particularly the more intelligent ones, are going to have their DNA tested for harmful mutations that could cause handicap or genetic disease at some stage in the child’s future life.
At present, if a potential mother needs to bave IVF treatment, she has the added bonus of knowing that the batch of eggs that have been artificially extracted from her and then fertilized will be examined for up to100 serious genetic diseases. In only those eggs in which there is no evidence of the gene mutations that cause, or predisposes, such diseases — one in two of them — will be re-implanted. But healthy young women who are fertilised naturally and give birth in the normal way cannot be reassured in the same way that her baby doesn’t carry the risk of a future genetic disease.
But perhaps before too long, women may want to know whether she has a faulty gene mutation somewhere in her DNA, even if she has been perfectly healthy so far. The chances are thousands to one against having a faulty gene to be seriously worried about if it is of the dominant variety. However, if she possesses it in her DNA — even though it might not yet have expressed itself in her — the chances are 50% that any of her children will also inherit the disease.
More serious, for childbirth purposes, are gene mutations of a recessive variety when, if she possesses a copy and her sexual partner possesses the same fault then, one of her children might have a double copy. Here, although the chances are only 25%, the actual frequency of recessive mutation is very much higher in the general population. In some regions, or among some ethnic groups, the chances of any individual having a particular recessive mutation — such as for cystic fibrosis — may be as low as one in 50 or 1 in 100.
Although genetic inheritance is infinitely more complex than briefly sketched above, the fact that more knowledge about genetic diseases will become known (if only by word of mouth from the increasing number of women who are having IVF treatment) among intelligent reasonably well-informed women, is probably going to mean that many will want to have their DNA tested when the cost is cheap enough.
But more than 4,000 serious genetic diseases have already been identified with, probably several thousand more not yet discovered, means that any apparently healthy young woman will be carrying some of them even if only a handful. Another complication is that a great many faulty genes don’t automatically cause a disease but only if it’s triggered off by some extra feature in the environment. Some of the faults that cause some types of breats cancer are of this sort.
Thus a full listing of one’s DNA listing all the faults and the potential ones is going to be worriesome to any lay person unless she also has guidance from a geneticist. But I think the need to have one’s DNA tested — and its undoubted future low cost and accessibility — will gradually assert itself aming intellingent young women in future years, even if a much more expensive consultation is also necessary for guidance.
Furthermore, it’s only one small step for young women to ask any possible young man she favours to have his DNA sequenced also. And then, if the romance proceeds further to possible marriage, they will want to have their DNAs compared for any possibility of double-matching. This could lead even further to IVF treatment if a young woman and man with matched recessive mutations are still keen on getting married and having children. She might then be prepared to have IVF treatment when the time comes to seriously planning for a child so that any eggs with a double ration — or even a single copy of the faulty gene can be rejected and only one in which it is totally absent is selected for re-implantation.
Going still further into the moderately imagined future when even artificial gestation might be developed, then Dr Odent’s fears may be completely fulfilled. When children are seriousl desired then the whole process, from in vitro fertilization onwards through to gestation in an artificial womb and right up to birth when a baby is taken away from a machine in much the same way that now happens with preterm babies — except in this case the babies will have completed a full term.