Hi L.!
As a mother of multiples to another, I promise you this will get better. My son took forver to eat during feedings when they were infants, which through off their schedule, but this is what we did.
I don't know the age but this is what we did. If they are still feeding in the middle of the night, the number one rule with multiples is if one eats, they all eat. Wake them up and get them fed so they can get back to sleep.
If they are older, you may want to experiement with different nap times. When mine were toddlers they took a morning and afternoon nap. So when they started not to sleep, I just took the morning nap away. If they are only taking one nap, I would keep it to two hours max. Maybe right after lunch. This way, when its time to sleep, they are tired!
Next, I would see what is going on while they are in daycare. If too much tv is on, they could possibly not be getting enough exercise to want to sleep. My kids were ready to sleep through the night, they slept a good 12 hours a night until they were about three, 7 pm - 7 am. (Although my daughter had a phase at the age of 2 when she would get up at 10:00 pm on the dot every night for about a year!!! It got to be hilareous...but I just put her right back to bed after some milk and rocking her a bit!)
Another thing that is not recommended by pediatricians, but is highly recommended by me and the lactation nurse that I talked to before I got to take the twins home! LOL My twins thrived on sleeping towards each other. They did until they were four, almost five. It is soothing to them, their bond is so great. (I wish it was this way during the day! LOL) They started out seprate, but they always ended up in the same position, in the same bed. Your triplets might do better like this too. Of course we still had seperate beds for them, but when they are toddlers, I put them in a queen size bed with rails for a little while to help them sleep.
Good luck! God bless you. Please remember, this too will pass. Although when you are the mother of multiples, simple problems always seem like they are bigger!
Take care~
Lee
P.S. Talk to your pediatritian and make sure they aren't having any gas on their tummies or allergies. And I always made sure that my babies went to bed with some milk if they were young toddlers, formula if they were infants. (Even though they say water is always better when they are toddlers...I did whatever worked.) Going with a full stomach helped them to relax and stay asleep longer. Let me know how it goes!