Interview with Vivette Glover

Today I’m talking to Vivette Glover, who is Professor of Perinatal Psychobiology at Imperial College, London. Vivette. We’ve been exploring in this course, the way in which the parents’ emotional mind and their cognitive mind influence the development of the foetus. Can you start by telling us a little bit about foetal programming? Yes. Foetal programming is the idea that the environment in the womb affects how the foetus develops, with a long term effect on the child. We’ve always known that how we turn out depends on an interaction between our genes and our environment. What we now realise is the environment starts in the womb.

So can you tell us a little bit about what the particular aspects of the environment are that are important? Well, there are different ones depending on what outcome one’s interested in. This whole subject was given a great impetus by the work of David Barker. And he found that babies that had grown less well in the womb, smaller babies, were more likely to die of cardiovascular disease in their 70s than larger babies. So he formulated what was called the Barker hypothesis. That was that undernutrition, as he called it in the womb, predisposed to vulnerabilities to the metabolic syndrome in later life. That’s cardiovascular disease, raised blood pressure, diabetes, obesity. And we now understand a lot about the mechanisms underlying that.

That if the baby is grown less well than it was genetically designed to in the womb, the less kidney cells laid down, less pancreatic cells. And that makes it harder for the child and later adult to deal with environmental problems such as high salt in later life. Makes he or she more vulnerable to cardiovascular disease and so on. If the baby was small because the parents are genetically small, or they come from an ethnic group that is small, then that’s not a problem. It’s only if they’ve grown less well than they were genetically designed to. So the original interest was really in the nutritional status of the mother. Yes.

Though we now understand that how the baby grows in the womb depends on lots of factors. So the nutritional status of mother is only one. In fact, rather a minor one. If the mother has very little calorie intake, less than a thousand calories a day, then the baby is smaller. But there are actually a lot of other reasons why the baby can grow less well in the womb. It is not primarily usually the nutritional state of the mother. OK. So we’ve discovered recently about the importance of the mother’s emotional state of mind in pregnancy and in particular, things such as anxiety and depression. Can you tell us a bit about what that research tells us? Yes.

We now realise that foetal programming is as important for neural development and for vulnerability to psychopathology, as it is for physical development and vulnerability to physical disease. There’s now a lot of evidence that if a mother is anxious or depressed or stressed while she’s pregnant, this affects the development of the foetal brain and has an impact on the later child. It has an increased risk. All the things we’re talking about are increase of risk. Most children of even very stressful, depressed mothers actually aren’t affected.

But if the mother is in the top 15% for anxiety or depression in a normal population, this doubles the risk of her child having symptoms of ADHD or conduct disorder or emotional problems as they grow up. So what you’re saying is that the duration and the chronicity of her experience of anxiety or depression, affects whether the foetus is adversely affected. We don’t know very much about the duration or the chronicity, actually. That’s an aspect that we need to have much more evidence about. We know that if she is anxious or depressed at some stage in pregnancy, that does increase the risk, but there are a lot of unknown questions about the timing and the chronicity.

So it’s essentially the severity that is the key issue. Well also, there’s a lot we need to know about that. In some of our research, we found a dose response curve. That the more anxious the mother was, the greater the risk of the child having problems. But it’s not true to say it’s only toxic stress or extreme stress that matters. Some studies have found increased risk for the child if the mother’s exposed to more daily hassles, for example. Or if she has increased pregnancy-related anxiety. So there does seem to be a dose response curve. But we mustn’t just focus on the very extreme end.

There’s some evidence that for some outcomes for cognitive development and physical maturation, that a certain amount of stress actually can improve outcome. Prove cognitive development. And it’s been suggested that for some outcomes, it might be an inverse U-shaped curve. That a little bit of stress improves and a lot of stress makes the outcome worse. But I think a lot depends which outcomes you’re looking at. For emotional behavioural outcomes, we haven’t found that. We just found a linear dose response curve. So what other sorts of outcomes are affected by anxiety and depression in pregnancy? Well, one thing that’s striking about this research is the wide range of outcomes that can be affected.

There’s emotional, a child’s more likely to be anxious or depressed themselves ADHD, conduct disorder, cognitive development. Some studies have looked at, particularly, language development. There also can be an impact on physical development. The babies are somewhat more likely to be born a few days early, or a little bit lower in weight. It’s a fairly small effect. but well-reproduced in large studies. There can also be physical effects. There can be effects on the immune system, more vulnerability to asthma. Two recent studies have shown a decrease in telomere length. And that’s interesting because the telomere is the end of the DNA, and a shorter telomere length is associated with living less long.

So the one thing that’s really striking is there’s certainly not just one outcome that’s affected. There seem to be a range of outcomes, that are affected. We’re starting to do research now on trying to understand why some children are affected and not others and we’re starting to have evidence that there’s a gene environment interaction. So that if the child has a particular form of gene, for example, it causes vulnerability to emotional problems. Then, if the mother is anxious while she’s pregnant, they’re more likely to have emotional problems. So you have another form of the gene, very resilient. And the same with symptoms of ADHD, the same with memory.

So, we think that what’s happening is that if the mother is anxious in pregnancy and the child has a particular genetic vulnerability to a particular condition and that double whammy can make the child have that increased risk of that outcome. And things aren’t all over at birth. The outcome is also affected by the quality of the mothering. The attachment and so on. We’ve also found that the child is securely attached. For example, that could protect against some problems with cognitive outcomes. So what are the mechanisms by which this happens in pregnancy? Well, from animal models, we’ve had a particular focus on the HPA axis, a system that makes us stressful in cortisol.

But in humans, we’re not rats and it looks as though it could be a bit different. If the mother is stressed or actually so depressed, her cortisol often doesn’t go up very much. And we actually don’t know what the biological change in the mother is, that’s significant for this. There must be something. We’ve looked quite a lot, and others are too, at the function of the placenta. And it’s clear the placenta filters what passes from the mother to the foetus. And if the mother is anxious or depressed, this affects the function of her placenta. And allows more cortisol to pass through. So even if the mother’s own cortisol isn’t raised, the foetus may be exposed to more cortisol.

We’re also getting some evidence that there’s a decrease in the enzyme that breaks down serotonin and the foetus may be more exposed to serotonin too. And we know that if the foetal brain and development is exposed to higher levels of cortisol or serotonin, that can affect the neural development. So we’re just starting to begin to understand the underlying mechanisms, but we’re only scratching the surface of understanding that. More research is needed. Much more research. But it’s not so much a mystery. I mean, we could see the sort of pathways that are likely to be underlying this. So in terms of the mechanisms, what does recent research about epigenetics tell us?

There’s a lot of research now in this area about epigenetics. Epigenetics means on top of genetics. And it’s how genes are expressed. Whether a gene is turned on or off or how much it’s turned on or off. And that’s affected by the environment. And we think and there’s growing evidence, that a lot of these effects on the foetus and the child are mediated by epigenetic changes. So that if the foetus in the womb is exposed to higher levels of cortisol, this could cause epigenetic changes in the brain. Which then affect the development of the brain. So what sorts of things can we do to help women in pregnancy who are experiencing high levels of anxiety or depression?

Well there’s a range of things we can do. We know that perinatal services is still a Cinderella, well mental health services in general, is Cinderella of the NHS. We know that most women who are anxious or depressed in pregnancy, this isn’t picked up and they’re not treated. So the first thing to do is to have increased training of midwives and health visitors, obstetricians, so that they detect this. There’s a lot of willingness to do it, but they haven’t got time and they’re not properly trained often, though that’s improving.

Professionals looking after pregnant women have to be much more aware that these are very important problems for the mother and for the child, and to detect an offer treatment.

Then as a society, there’s a lot more we can do. Employers need to be aware that this could be a problem. And some women love working through pregnancy. But some don’t. Some find it’s getting too much, physical activity could be too much. There should be much more sensitivity to giving women a choice of how and when they work during pregnancy. We know that social support is very important. The partner is probably the most important of all. The support of partner can really buffer against emotional problems in other. Not completely, but they could do a lot to help. An abusive partner could, on the other hand, make things much worse.

So I think to be aware of the role of the partner, health professionals and others ought to help bring the partner in to maternity services. And friends, family, we all could do a lot to support pregnant women. Then in terms of what actual professional help can be offered, there’s a range of things depending on the problem. But we know how to treat anxiety and depression, and it’s not different in pregnancy. So if it’s very severe, a woman’s very severely depressed, antidepressants are probably indicated. But for many other women, it won’t be the right thing. So one could try CBT or IPT or mindfulness. A lot of interventions that can help.

But the main thing, I think, is not which intervention - though that has to be worked out - but detection and then having enough people who can provide interventions. And you’ve developed a website that is targeted at both parents and professionals? Yes. Yes. Just to tell people more about all the things we’ve been discussing. It’s called Begin Before Birth. If you google Begin Before Birth. What sort of things will people find on the website? Well, they’ll find more about the effects on the child, the nature of anxiety and depression, the underlying mechanisms. Vivette, this is fascinating material. Thank you very much.