One in five pregnant women say they do not feel "emotionally ready" to have a baby, a survey has revealed.
Many women find pregnancy harder than they expected
The poll of 1,100 women for Tommy's baby charity found many women were surprised at the physical and emotional demands of pregnancy.
Half felt under pressure to be "perfect", and 44% said those around them felt the need to pass on "tips".
Experts said more services should be available to support pregnant women and to stop them feeling so isolated.
Tommy's, which funds research into the causes of, miscarriage, stillbirth and premature birth, found 67% felt more exhausted than expected during pregnancy, and 58% felt more emotional.
Over half said they felt more in need of reassurance than they expected, but 29% felt confused by all the conflicting advice they read.
A third said they had received personal comments that upset them, such as being told about other people's pregnancy and birth "horror stories".
One woman said: "People find it entirely acceptable to pass comment about my body shape whilst I am pregnant - the size of my hips, the weight I'm carrying, the size and position of my bump.
"They would never dream of being so direct and rude if I wasn't pregnant."
Just over a quarter (27%) said they were weighed down by relationship or financial pressures.
And 10% of pregnant women felt pressure from friends who said they had "lost" them socially.
The poll also found that 21% felt pressure from media coverage of celebrities who appeared to lose all their pregnancy weight straight away.
Dr Linda Papadopolous, a spokeswoman for Tommy's, the baby charity, said: "These are alarming statistics as they show just how little pregnant women are being supported through their pregnancy - and how this is detrimentally affecting them, both mentally and physically.
"Pregnant women must be reassured that their emotional feelings and stress are commonplace.
"They're not alone in feeling like this and there are plenty of support services available to them."
She added: "It's evident that the mounting pressure on women to remain perfect throughout pregnancy and motherhood is huge.
"This problem needs to be addressed - women mustn't be left feeling so isolated. They need support and good clear pregnancy health advice."
Mary Newburn, of the National Childbirth Trust, said: "Pregnancy causes enormous physical, social and emotional changes for women - often the impact is greater than you anticipate beforehand, but every pregnancy is different and so many factors play a part in how you will feel.
"One thing that holds true for every pregnant women is that it's good to talk to people who listen and understand.
'Unfortunately, reductions in the number of antenatal visits may mean that women have longer to wait between appointments, and have fewer opportunities to talk about the changes they are experiencing and ask questions.
"They may feel more isolated and less well supported as a result."