How Life in the Womb Shapes Us
Researchers have just added a prequel to the nurture/nature debate. At last the scientific world is getting wise to the effects that the first ever environment encountered - the womb - has upon the developing foetus. According to the emerging field of foetal (fetal) origins, events and experiences encountered before birth determine the future likelihood of health problems, well-being, intelligence and temperament for the rest of life.
Researchers now recognise that the mother is not just a biological incubator and that the foetus is not just a lump of developing flesh, but that the process is very dynamic and best prepares the baby for the world it is likely to encounter at birth.
The speciality of foetal origins is currently the focus of many research papers, books and conferences and the information being revealed is overturning much of what was previously believed about this formative stage.
During pregnancy, the developing foetus is exposed by proxy to the life of the mother, with its internal biochemistry, exposure to pollution, diet and stresses and these factors all serve to prime the system.
The first thing to appreciate is that there is no one 'ideal' pregnancy, only a pregnancy that best equips the baby for birth and survival in its unique environment. Historically, the focus in medicine has been on what can go 'wrong' during pregnancy, whereas foetal origins examines what processes best prepare the foetus for the life it will encounter.
Current research has shown some of the factors listed below have significant and potentially life-long effects.
The effects of stress
Moderate amounts of stress during pregnancy appear to promote development of the foetal nervous system such that babies at 2 weeks of age are measurably more developed. In addition, the babies of mothers who had been moderately stressed or anxious during their pregnancy showed more mature brains and better motor and mental development scores at 2 years of age.
However, the babies of mothers who had been exposed to extreme stress during pregnancy were more likely to be born earlier. The offspring of pregnant women who had experienced a serious earthquake in California showed delayed development. And the children of mothers who had suffered a severe ice storm in Canada showed early signs of post-traumatic stress syndrome - as have some of the babies whose pregnant mothers were involved in the 9/11 disaster.
Exercise during pregnancy
It turns out that exercise during pregnancy is good for the foetus - contrary to current advice to avoid exercise during pregnancy. The babies of women who had exercised during pregnancy showed slower and more variable heart rates - which are both signs of cardiovascular health. The babies of mothers that had exercised during pregnancy also had lower birth weights and may become more intelligent adults because they had proportionately bigger brains.
Diet and pregnancy
Many pregnant mothers are wary of eating fish because of the issue of mercury contamination. However, the benefits have been shown to outweigh the disadvantages provided the mother consumes fish high in omega 3 oils and eats only fish such as sardines, tilapia and salmon which accumulate relatively little mercury. The children of mothers who ate at least 12 ounces of seafood a week had higher verbal IQs, better social and communication skills and superior motor skills according to a paper published in The Lancet.
The counsel to avoid sweets during pregnancy apparently comes with one important caveat too: chocolate. Women who ate chocolate every day during pregnancy were shown to have babies that were less fearful and who smiled and laughed more. Eating chocolate 5 or 6 times a week in the third trimester also reduced the chances of the dangerously high blood pressure condition known as preeclampsia by 40%.
Mental health
In the one in ten women who suffer with clinical depression, there was an increased risk of premature delivery and low birth weight. The children too were more likely to be predisposed to mood disorders. This finding may be a direct result of the maternal transfer of toxins rather than the effects of the mother's biochemistry on the developing foetus.
Epigenetics
The field of epigenetics may explain some of the findings emerging from foetal origin studies. This is the study of factors that control the expression of the genome in a cell or individual in a particular environment and is thought to be more important than the study of genetics. The genome alone cannot explain many findings since humans have a fraction of the genes originally thought to be necessary and estimates are that less than 2% of the genome is expressed.
The US National Institutes of Health is currently undertaking a $190 million research project which they consider may hold clues to explaining the mechanisms of ageing, human development and disease.
Several different factors have been identified that can activate or silence parts of the genetic code. These include:
-
The way the DNA double helix is wound around the proteins known as histones in chromatin
-
Whether specific bases are subject to methylation which makes them less active when it comes to transcription
-
Changes in the way the DNA strands are packed and
-
Changes in the way DNA opens up to allow transcription
A study conducted by Marcus Pembrey and colleagues found that the paternal grandsons of Swedish boys who had been children during a 19th century famine were less likely to die of cardiovascular disease. Whereas, the grandchildren of those for whom food had been plentiful were more likely to become diabetic, suggesting a transgenerational epigenetic inheritance. However, the opposite was true of females where the paternal granddaughters of women who experienced famine while in the womb lived shorter lives on average.
These findings give credence to the concept of 'organic evolution' outlined by Jean-Baptiste Lamarck over two centuries ago. He maintained that animals actively interacted with, and adapted to, their environments and that these changes could be handed down. Unlike Charles Darwin's concept that such changes were thrown up occasionally as a result of chance and then pruned by the environment in a process known as natural selection. Although the less renowned of the two, he may yet be vindicated by the emerging science.
Further resources
The book Origins: How the Nine Months Before Birth Shape the Rest of Our Lives by Annie Murphy Paul is available from Amazon UK and US.
"As the executive director of 'The International Academy of Biological Dentistry and Medicine' I spend hours talking to patients trying to find dentists that practice biological dentistry and physicians that can help with their health problems that may have been caused by dentistry. Many of those patients are seekers. This is an excellent book for patients. It is easy to understand and helps guide them towards health."
.jpg)
