Maternity units are facing cuts despite dealing with a high birthrate and more complex births, a survey has shown.
Some 30% of the most senior midwives said their units have seen a fall in their budget in the past year while 33% have been asked to cut staffing levels.
The Royal College of Midwives (RCM) surveyed 83 out of 194 heads of midwifery across the UK at the start of its annual conference in Manchester.
Two-thirds (67%) of those questioned said they did not have enough staff to cope with demand, despite a high birthrate.
The number of live births in England rose by 107,314 (19%) between 2001 and 2009 to more than 670,000 a year.
But the number of NHS midwives rose by just over 2,000 (full-time equivalent posts) over the same period, a rise of 12%.
Almost half (47%) of the heads of midwifery surveyed said they expected to be told to cut their staffing levels over the next year.
This is despite more complex births involving obese pregnant women and older or teenage women, who often need extra support and can have more complicated deliveries.
Almost all parts of England have vacancies for midwives over the generally accepted vacancy rate of 3%, said the RCM.
London has a vacancy rate over 15% and it stands at more than 8% in the east of England.