The research, from Key Note, says that a continuation of the trend of fewer marriages is most likely to impact on the middle market.
It says the most recent figures for the number of weddings in the England and Wales show drop of more than 10% in 2005, compared to the previous year.
Keynote says that the niche nature of the bridalwear market in the UK, especially at the higher end, means designers can withstand seasonal fluctuations.
However, the mid-market would suffer most, as is already highly price competitive thanks to increased sourcing from China, according to the report.
A survey of designers showed that many were expanding their occasionwear offer, especially prom dresses.