Choosing to include children at your wedding or not should be a decision made by YOU... at the end of the day it is YOUR wedding, YOUR day and should be what YOU want...
Often children play important roles in a wedding... usually flower girls or ring bearers... and the guests love seeing them in their gorgeous little bridesmaid dresses and suits.
There are more options than simply yes or no to having children involved in a wedding. Often couples will opt for a no children at reception rule but they welcome them to the ceremony. Your guests will have plenty of time to organise baby sitters and it keeps the costs down for the reception.
Some couples even organise to have a baby sitter at the reception venue (or even a location close to the venue where the children can go after the ceremony for a kids party)... keeps the children entertained and allows the adults to enjoy themselves without worrying about the kids.
If you do opt to include children at the reception then its a great idea to have kids activities there for them to do... pinterest has some great ideas for kids wedding activity packs.
Below is a kids table set out from one of my couples... the children LOVED it and it kept them entertained for ages.
If you do choose to have NO children at your wedding then most guests will understand... all parents know that children can be unpredictable, they cry, make messes and we can't forget every parents favourite two words... "I"M BORED".
Some guests however wont understand... especially if their child is slightly older or a baby... unfortunately it is easier to enforce a no children rule than a no children up to a certain age rule.
A suggestion is to ring those guests with children before sending the invites out to them and explain that you have chosen to have a child free wedding. This gives them plenty of time to find a sitter. Another option is to write on the RSVP card "adult reception" or "we have reserved 2 adult seats in your honor".
Either way... children or no children... it is YOUR wedding day so you shouldn't feel pressured either way.