A Freedom of Information (FoI) request found the maternity ward at the Royal Berkshire Hospital was closed on 47 occasions last year.
The hospital delivers about 500 babies a month, but some pregnant women had to be "diverted" to other hospitals.
The Royal Berkshire said midwife recruitment was improving.
Rebecca Pullen who was turned away from the Royal Berkshire Hospital (RBH) last year, said she was told the labour ward was "completely closed".
She was driven to a maternity unit in High Wycombe before eventually being driven back to the RBH.
She said: "When it's your first baby, it's terrifying - you don't know what's going to happen, you don't know where you're going to have your baby.
"And the fact my birth plan wasn't taken into account wasn't ideal."
Up to 13% of midwife posts at the RBH were vacant in March 2016, while the annual spend on agency midwives rose from Â£10,221 in 2014 -2015 to Â£198,170 in 2015-2016.
Nationally, the recommended consultant cover for a maternity unit that delivers more than 5,000 births a year is 168 hours a week.
Consultant cover at the RBH in 2014 was between 68 to 91 hours per week, a recent Care Quality Commission inspection found.
Gill Valentine, director of midwifery at the hospital, said the RBH had recruited a number of "high calibre" new staff and expected to achieve the recommended 168 hours of consultant cover in 2016.
"I accept we divert more frequently than we'd like to, but the only reason we do that is to maintain the safety of the mums and babies and that is of paramount importance," she said.
A total of 81 expectant mothers were turned away from a labour ward at a hospital last year due to staff shortages, the BBC has learned.