Moreover, women who have experienced mental illness previously, however mild, are far more likely to have a recurrence of their illness or for its symptoms to become more extreme during this same period.

The underlying causes of depression during pregnancy are multi-various. The physical strains of pregnancy, such as sickness, fatigue and, for some, limited mobility can cause a woman’s mood to be affected. These physical triggers do not only have a psychological effect but measurable physiological ones too: sickness can lead to imbalances in electrolytes with cascading consequences on hormones which can and do alter mood.

Fatigue may itself be a symptom of underlying depression or the lack of mobility it and the change in body shape and the pressure that puts on the joints may mean exercise may be reduced and restricted during pregnancy – study upon study has shown regular, physical exercise to be a valuable tool in combating mild to moderate depression.

All of this can trigger depression in a woman who has never before experienced this illness or cause a worsening or recurrence of the condition in those who have a history as a sufferer.

Of course, psychological factors come into play and these, it is believed, play a more important role in the risk that a person will experience depressive illness during pregnancy if this is the first pregnancy.

Changes in sleeping patterns can be of the first signs of depression be that insomnia, sleeping for excessively long periods, unusual wakefulness for example during the night. Of course dyspepsia, a kicking baby and a whole host of other causes may come into play in modulating how much sleep a woman can achieve in each twenty four hours but the reasons for changes in sleep routine should be examined. Changes in appetite including bingeing or under-eating can also indicate depression but again other causes may come into play.

Lack of interest or excitement is a key indicator of depression. Pregnancy is an exciting time but women who are diagnosed with depression during pregnancy often report a feeling of numbness or that they can’t envision the end of their pregnancy. On the other side of the scale, excessive anxiety and emotion can also indicate depressive illness. Should a woman find her mood swinging between these extremes it is possible she may be suffering from bipolar disorder, that is, manic depression as it was once known.

Should you be diagnosed with depressive illness during pregnancy or already suffer from the condition you may still be able to take certain anti-depressant medications. You will need to consult closely with your doctor as to which will be suitable for use during pregnancy and, should you need them after birth, which are suitable for breast feeding mothers should you choose to feed your child that way. You may also be offered counselling, however, waiting lists can be very long and you may be advised to seek a private counsellor or seek a support group or help from mental health charities such as SANE and in Dublin, a good choice is AWARE.

To reduce the risk of suffering from or the worsening of symptoms of mental illness it is essential to be honest and open with your health care providers when you are asked about your mental health, mental health history and that of your family.

If you currently suffer from a mental health condition it may be necessary to alter any medication you take for the safety of your unborn baby or to manage new and/or changing symptoms. This should be done in close consultation with your doctor – suddenly stopping medication can cause symptom to recur and worsen significantly especially during pregnancy.

Keep active and eat healthily. Maintaining your weight within healthy limits will help to reduce the risk of joint problems and immobility later in pregnancy. Exercise has been shown to ward off depression but it is equally important to find time to relax and take part in activities you enjoy. Make an effort to go out of the house every day and keep contact with friends and ask for their help if you need it – many women who suffer mental health problems often report feeling “over burdened.” Of course, for a healthy pregnancy avoid alcohol and caffeine.