Not necessarily, though pensions are included in your total assets that need to be considered.  (If in Scotland only pensions accrued during marriage are considered).

If you have only had a short marriage or one of you has special needs, then the division of assets need not be 50/50.

Even if you do need to share assets 50/50 then you do not have to share your pension, you might say keep your pension while your spouse keeps your house.  This is known as offsetting.