Soldiers are freezing their sperm before they serve in Afghanistan or Iraq so their partners can still have children if they are killed in action.
Soldiers see the procedure as an "insurance policy"
The "posthumous" sperm is being stored, legally, at the Midland Fertility Clinic in the Black Country.
Herefordshire-based soldiers are among those using the "insurance policy" service, clinic officials told BBC Hereford and Worcester.
No babies have yet been born through the procedure.
Dr Gillian Lockwood, director of the clinic, which has bases in Wolverhampton and Aldridge, said: "It is always bleak to think the worst might happen, but on the other hand the chaps do feel that if they plan for the worst then the best will happen."
The couples from Herefordshire are among a "small number" who have stored sperm, but Dr Lockwood said that may be because the service is not widely known.
"We've had approaches and we have certainly got sperm in our freezer from our brave chaps serving overseas," she added.
Herefordshire is widely believed to be the base of the special forces SAS.
It is not known how long sperm can remain effective but, with efficient freezing it is thought to be at least 20 years.