Almost a third of pregnant women suffer strong feelings of depression and anxiety, a survey has found.
The poll found that many are struggling with signs of antenatal depression - depression in pregnancy - but are afraid to tell their doctor or midwife.
NHS data suggests up to 15 per cent of women suffer antenatal depression, although the new survey suggests this could be far higher.
About 30 per cent of mothers-to-be frequently experience five or more key indicators of antenatal depression, the poll found.
These include feeling anxious for no reason, losing interest in day-to-day activities and feeling so unhappy they cry.
If the figure was extrapolated across all pregnancies, this suggests almost a quarter of a million women a year in Britain suffer from depression during pregnancy.
The poll of 1000 mothers and pregnant women, from BabyCentre, also found 42 per cent had never told their doctor or midwife about their symptoms of depression.
The top three reasons were they felt guilty, embarrassed or worried that others would judge them.
Almost half did not want to be labelled as mentally ill, while 26 per cent had not even discussed the issue with a partner, close friend or relative.
More than one in five (21 per cent) had not done anything at all to address their symptoms.
Sasha Miller, international managing editor of BabyCentre, said: "Our study paints a stark picture of the alternative face of pregnancy - it's not all baby showers, blossoming bumps and baby moons.
"While pregnancy is an emotional time for any woman and occasional mood swings are normal, so many women experiencing so many symptoms so much of the time is a serious problem.
"Women feel under pressure to act like they are having a perfect pregnancy but the reality is very different for huge numbers of mums-to-be.
"There is still a stigma attached to depression and our research shows that admitting to suffering from symptoms whilst pregnant is something many expectant mums feel unable to do. As a result they aren't seeking the help and support they need from health professionals. This needs to change."
