A woman left with PTSD after the birth of her daughter says she relived the trauma "over and over again" as she cared for her newborn.
Anna Simpson described the emergency C-section as the most frightening experience of her life.
A study has suggested up to 28,000 women a year in the UK could be affected by maternal post-traumatic stress disorder.
NHS England said it was "improving mental health support for new mums".
Ms Simpson, 34, from Wakefield in West Yorkshire, was rushed to an operating theatre with her unborn daughter Macie in the breech position, after two unsuccessful attempts to move the baby in the womb.
"There were a lot of people around me," she said.
"There was an anaesthetist trying to put a cannula in my hand so I felt like it was being attacked, it felt very frightening, I was very scared."
Experts warn that PTSD - commonly associated with soldiers returning from war - is harder to treat the longer it goes undiagnosed.
A traumatic birth can involve unexpected events including the baby's heart rate dropping significantly, an emergency caesarean section and the mother losing several pints of blood after haemorrhaging.
Mothers have a post-natal appointment about six weeks after the baby's birth to assess recovery and check for post-natal depression, but PTSD is not routinely looked for.
Ms Simpson, whose daughter is now 16 months old, said: "I was going through the birth over and over again, it was exhausting and really painful.
"It was physically draining, all that on top of having to look after a new baby was really difficult."
Months after the birth, she noticed her emotions were not fading so tried cognitive behavioural therapy (CBT) followed by a successful programme of eye movement desensitisation and reprocessing (EMDR).
EMDR works on the theory that traumatic memories have not been properly processed by the brain, but can be reprocessed correctly via therapy involving eye movement, aural and physical prompts.
Common signs of PTSD and birth trauma
- Vivid flashbacks
- Intrusive thoughts and images
- Intense distress and real or symbolic reminders of the trauma
- Physical sensations such as pain, sweating, nausea or trembling
Research from academics at City, University of London, published in the Journal of Affective Disorders, suggested 3-4% of women report PTSD in pregnancy and after birth.
Using this percentage, they calculated 28,000 women could be affected in the UK each year.
Prof Susan Ayers, who co-authored the study, said: "We need to raise awareness of birth trauma and PTSD both in the general public but also in professionals that come in contact with women.
"We need to train healthcare professional in terms of identifying [affected] women and we also need to have clear, effective evidence-based treatments."
Dr Rebecca Moore, from the Royal College of Psychiatrists, said many women who experienced PTSD were being "failed by the current provision".
"Many women who have had a traumatic birth in the UK are not diagnosed, misdiagnosed or cannot access rapid, specialist, trauma-specific treatment," she added.
Kim Thomas, from the Birth Trauma Association, said: "We have had women come to us who have had their traumatic birth experience 20 or 30 years ago and they are still experiencing the symptoms.
"If you don't get treatment then your symptoms can go on for years and years."
Sources of support for PTSD and birth trauma include:
Ms Simpson suggested the therapy she went through had helped her recover.
"I just don't feel fragile anymore, the emotion that was bubbling under the surface all the time has gone and I can talk about it," she said.
"It's so nice for me because really it was a lovely thing for me to have a baby, it is so nice to be able to talk about it now."
In a statement, NHS England said: "Any form of mental ill-health during pregnancy, labour or early parenthood is of real concern, but great strides have been made in improving mental health support for new mums with 7,000 more women receiving treatment last year.
"In addition, specialist mental health services will be available in every single part of England by April next year and the long-term plan for the NHS will set out further improvements in care."