More than 300 pregnant female service personnel had to be flown home from Iraq, Afghanistan, Cyprus and the Gulf, according to government documents.
The figures obtained in a Freedom of Information request also show that 54 women had to be airlifted from Royal Navy ships or flown home from foreign ports after discovering they were pregnant at sea.
The figures for the period 2008 to December 2022, show that up to 319 female troops were medically evacuated.
Of those 173 were female soldiers, 92 were members of the RAF and 54 were serving in the Royal Navy.
The female sailors were evacuated from at least 10 warships, including the £1bn HMS Duncan, an air defence destroyer and one of the Navy’s most modern ships.
Three ships had 14 pregnancies between them HMS Ocean, which featured in a TV documentary, where at least five sailors were ordered to leave the ship.
But the vessel from where the most pregnant sailors were evacuated was HMS Montrose, a Type 23 Frigate which was decommissioned last month.
The Royal Navy has a strict no touching rule on board all ships even for married couples serving on the same vessels.
But relationships amongst sailors of all ranks takes place.
Last year Warrant Officer Gary Patterson was relieved of his duties after being filmed have sex with a female sailor while on board HMS Victorious, one of the Royal Navy’s trident submarines,
In 2014, commander Sarah West, the first woman to captain a Royal Navy warship, was flown back to the UK following claims she had a sexual relationship with a member of her crew.
The FOIs also reveal that female troops, mainly soldiers, were flown home from six separate military operations between 2008 and 2022.
Last year 11 women were flown home but the highest number was in 2008 when 50 female personnel discovered they were pregnant while on military operations.
Married soldiers are allowed to deploy on operations together but they must sleep in separate quarters and can only share a bed either on R and R.
In the most high profile case, a British soldier gave birth at the field hospital in Camp Bastion, Helmand province.
Lance Bombardier Lynette Pearce gave birth to a boy in September 2012 after reportedly being unaware she was pregnant.
Women have been serving on Royal Navy ships since 1990. In 2017, three women made history by becoming the first female submariners to serve in the Royal Navy.
An MoD spokesperson said:“We take the welfare of our people extremely seriously and if someone discovers and discloses they are pregnant they are returned to the UK as soon as possible.
“Personnel may not be aware they are pregnant at the point they deploy, to suggest some become pregnant while serving on an operation is speculation.”