Everyone has heard of postnatal depression. Most people do not know that symptoms of depression are as common during pregnancy, as after giving birth. Symptoms of anxiety are very common during pregnancy too. Some women are especially anxious specifically about the outcome of the pregnancy. Will the baby be alright? How will she cope with the labour? And some husbands or partners can find it a difficult time and there can be an increase in domestic abuse.

Having a baby very much increases the risk of the rare condition of postnatal psychosis, which is very serious, but only affects about one in 500 women. But symptoms of both depression and anxiety affect about one in 10 women both during pregnancy and afterwards. And this is very important, both because we need to help relieve the suffering of the woman herself, and because of the way it may affect her baby in her womb.

If a woman is stressed, anxious or depressed while she is pregnant, this increases the risk of her child having a range of problems later. It is important to emphasise that we are talking about risk; most children of even very depressed, anxious or stressed women will be fine. But the risk for a range of disorders, such as ADHD, anxiety or depression, difficult behaviour, some problems in learning, and some physical problems such as asthma, are doubled. Very severe stress, during the first trimester, such as the death of an older child, increases the risk of the future child having schizophrenia, but luckily, this is very rare.

Whether a child is affected or not depends in part on their own genetic makeup. If the child has a genetic vulnerability to ADHD, for example, and the mother is stressed during pregnancy, then they may develop such symptoms later. If they are genetically not vulnerable then they will not. Also, what happens in the womb, although it can alter the pattern of the development of both the body and the brain, does not mean that things cannot be changed later. We know that the sensitivity of mothering, responsiveness to the baby’s signals or cues, can help attachment, and that secure attachment can reverse some of these effects.

Recent research has shown that the mother’s own early experiences of trauma can alter the development of her fetus too, even if she is not depressed while she is pregnant. Brain imaging studies of the newly born babies of such mothers show clear differences in brain structure. Research is starting to uncover some of the biological mechanisms that cause the changes in development of the fetus, including the fetal brain.

The placenta is very important. It filters the chemicals and hormones that pass from the mother’s blood to the fetus, and how it does this can depend on the mother’s own biology and can be changed by her mental state. If she is anxious or depressed the placenta can allow more of the stress hormone cortisol to pass through, and this in turn can alter the development of the fetal brain. But many other systems are involved too, which we do not fully understand yet.

The implication of all this is that we all need to give much more help to pregnant women who feel stressed, depressed or anxious, both for themselves but also for their future children. Health professionals, midwives, GPs, obstetricians and health visitors, who see pregnant women need to spend more time to find out how they are feeling. This does not usually happen at the moment. Health professionals need to be aware that the pregnant woman may be feeling depressed, but she may also be feeling anxious, stressed by a difficult relationship with her partner, or feeling the effects of their own early experiences of abuse or trauma. Then they need to provide appropriate support. Often it will be talking therapies like cognitive behavioural therapy (CBT). If the woman is very depressed antidepressants may be needed, and most are safe to use during pregnancy.

The woman’s partner is very important. An abusive partner can cause stress which may alter the development of the baby in the womb. But a supportive partner can be a really helpful. Fathers can be crucial long before the baby is born, and should be welcomed into the preparations for the new baby. Other people in the family, such as the future grandmother can help too.

And employers need to understand about all this. There is no evidence that work itself is a problem, but if the working environment is such that the pregnant woman feels very stressed, then it may become so. We all need to look out more for pregnant women, and encourage them to talk to someone if they are having problems. They may like to take part in yoga classes, massage, or listen to relaxing music. There is evidence that all of these can help.

If we care better for the emotional state of pregnant women we will help not only them but the future generation.