It is normal for every expectant mother to feel nervous during her pregnancy. However, for some women, these jitters may be a sign of something much deeper.

Perinatal anxiety - defined as anxieties associated with childbirth and relating to pregnancy, delivery, post-pregnancy or childcare - is estimated to affect about 5 to 8 per cent of pregnant women and new mothers worldwide.

It is a less commonly studied condition than perinatal depression and presents different symptoms.

'In anxiety, the primary feature is excessive worrying, feeling tense with heart palpitations, breathlessness, restlessness and, in some instances, panic attacks in which the patient experiences severe anxiety and has a sense that she will collapse,' said Dr Helen Chen, head and senior consultant of the Mental Wellness Service at KK Women's and Children's Hospital (KKH).

Depression, on the other hand, presents itself in the form of low mood and loss of interest in activities or in life. There are also other symptoms such as poor sleep, poor appetite, loss of concentration, negative thoughts and, in severe cases, suicidal thoughts.

Of the 300 pregnant mothers that KKH's Mental Wellness Service has seen in the past 21/2 years, 52 have shown signs of antenatal anxiety. These are prominent anxiety symptoms during pregnancy which affect the functioning of the mother and her ability to adjust well to her pregnancy.

Twenty-five of the 200 post-pregnancy women who have used the hospital's service have been diagnosed with post-natal anxiety.

A mother with this condition develops anxious thoughts in relation to her baby. For example, she could feel irrational fear that her baby might stop breathing or choke while feeding. In severe cases, such anxieties may lead to tocophobia - an abnormal fear of giving birth.

Dr Jazlan Joosoph, a specialist in obstetrics and gynaecology at Raffles Hospital recalled a case he saw late last year in which a 24-year-old patient, though physically well but reserved by nature, opted against having a Caesarian section at all costs. She was fearful of going under the knife.

The labour progressed uneventfully but when her cervix was fully dilated and the time came to deliver the baby, the patient panicked and became hysterical.

'She was screaming and tossing around in bed. It took several doctors and nurses to calm her and pin her down so that the baby could be delivered safely,' recalled DrJoosoph, who had to use forceps to aid in the delivery.

In another case, a 27-year-old first-time mother he was attending to had developed a phobia of childbirth after hearing about her sister's difficult delivery.

'From the beginning of her pregnancy, she declared that she would not be able to handle the stress of labour and natural delivery; so she opted for a planned, elective caesarean section,' he said.

The operation was done last December and now mother and baby are both safe.

Why do some mothers get so anxious in the first place?

'Part of the anxiety has to do with their being overwhelmed with uncertainty. That's why this tends to occur less in women who have already had children. However, if a subsequent pregnancy produces new stresses for a woman, a second- or third-time mother can develop these anxieties too,' said Dr Chen.

Most doctors agree that perinatal anxiety, like post-natal depression, can affect women from a wide range of socio-economic backgrounds.

Women who are, by nature, more anxiety-prone or who have a personal medical history or family history of depression can be more vulnerable to perinatal anxiety during pregnancy and after childbirth, as these are the times they face increased physical and psychological stress.

'The trigger may not even be pregnancy-related; it may come from pressures at work or financial or relationship troubles, but all these can add to the feelings of anxiety that a pregnant or post-pregnancy mother may feel,' explained Dr Vanessa Keleher, a consultant psychiatrist at the National University Hospital.

Depending on the severity of each case, treatment usually involves group or individual counselling or a course of medication or both. Husbands are encouraged to sit in on the sessions. More than half of the patients would come with their husbands on the first visit but as the treatment progresses, husbands tend to attend intermittently, observed Dr Keleher.

She said that anti-depressant medication is prescribed only after extensive and careful consultation to discuss the benefits, possible side effects and risks for mother and baby.

Generally, she said , doctors would avoid prescribing medication in the early stages of pregnancy when the organs of a foetus are just developing and towards the end of the pregnancy when the baby may develop withdrawal phenomena. In this case, the infant would, after birth, be jittery, more prone to crying or refuse food.

Cases requiring psychiatric hospitalisation are rare, according to doctors.

'With good, strong spousal and family support and careful explanation, anticipation and reassurances from a caring and compassionate obstetrician, most cases of perinatal anxiety can be successfully managed,' said Dr Joosoph.

This article was first published in Mind Your Body, The Straits Times on Jan 29, 2009.