The age of marriage has gone up in Australia and what that means is that there are lots of people with kids at your wedding (and with baby sitters)

I’ve seen the changes over the last 14 or so years DJing at weddings in Adelaide and Melbourne and it’s HUGE! Especially with people deciding to have children before their own wedding (especially if they’re in their mid/late-thirties)
One of the main things to be aware of is the impact on your guests of the wedding itself. Often the location needs to be central if they’re coming from interstate otherwise it’s a 3 day trip for your wedding.
Consider getting a babysitter and/or nurse if you have lots of friends with small children, it makes a huge difference if there are professionals at your wedding to look after their kids, even if its just so they can relax over dinner.
Keep the wedding relatively compact, its easier if the wedding ceremony and reception are at the same venue, it cuts down on the time of the entire day for the parents (who got up at 6am and will be up at 6am the next day!)

Make sure the venue has places to breastfeed (although it’s becoming socially acceptable to breast feed in public now, which is awesome) and also quiet spaces that parents can take their children if they need a bit of a ‘timeout’ from the festivities.
Encourage your friends to have a “backup” plan in case their babysitter falls through, nothing worse than a best friend that can’t make it to your wedding at the last minute!
Make sure you have lots of seating, shade and water for your guests during the ceremony if it’s outside, this is always a good idea but it’s imperative if you have pregnant women, children or the elderly at your wedding.

Have something for the kids to do at the wedding. I’ve seen clowns, Duplo blankets, Crayon stations and even included some choreographed kids dances during the reception to make sure the kids had something to do throughout the night so that their parents don’t need to keep them amused.

Another important consideration is whether to make your wedding children-free. A good rule is to allow parents with breast/bottle fed aged children as they may not be able to come otherwise (due to the feeding schedule) and small children are generally pretty easy to deal with. Since young children don’t require a meal it also might save you thousands on your food and beverage package, especially if you’re at a venue that charges full adult rate!
You should also get some children’s ear muffs for little children if you’re going to have a raging dancefloor, not only do they protect the childrens hearing, infancts usually love them as it reminds them of the sound of being in the womb and the gentle pressure of the earmuffs can be comforting (much like a swaddle)