Sperm donations appear to have fallen after donors’ right to anonymity was removed in 2005. The rules surrounding donation now mandate that children be allowed to know the identity of their genetic parents when they reach 18, the BBC reports.

In order to make up for a shortfall, clinics are relying on imported sperm, and may be lowering standards for sperm donors.

In addition, doctors say, the decreased sperm supply may lead people to conduct risky insemination practices like do-it-yourself insemination with a friend’s sperm, or seek fertility treatments in countries with less regulation than the UK.