One in 20 pension professionals said their confidence levels in the asset and liability valuations of the schemes they work is less than 50 per cent, according to a global survey by investment manager State Street.
And 77 per cent of survey respondents said the challenge of navigating the adoption of new investment strategies was "high" or "very high", while 75 per cent believed the challenge of effectively aligning assets with liabilities was "high" or "very high".
It comes as the world's ageing population, historically low interest rates and market volatility are all contributing to widening pension deficits, the gap between assets and liabilities. In the UK, this has been highlighted by BHS and Tata Steel.
"As asset owners become more sophisticated in their investment strategies, they invest in a wider range of asset classes and this can make it more difficult to assess their true value," Oliver Berger, senior vice president and head strategic market initiatives for Europe, Middle East and Africa, said.
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"Advances in medical treatment and changes within society as a whole can also make it more difficult for pension funds to assess the extent of their liabilities," he added.
The research was based on the responses of 400 pension fund professionals across 20 countries.