The 30 minute nap has a bad wrap. In reality, sometimes it needs fixing and sometimes it completely normal! Let's talk about when to leave it and when to fix it.
Newborns
If your newborn is taking 30-minute naps the first place I look is their feeds. Are they falling asleep during their feed and are you calculating their wake window from then?
Newborns are generally sleepy! It is often a struggle to keep them awake during feeds. You can try all of the tricks like blowing on their face, tickling their toes, even taking off their diaper if you're brave! But when none of that works and they're basically sleeping while they're eating you're going to want to keep them up for their 45-60 minute wake window from the time they finish their sleepy feed, not from when they woke up from the last nap. Newborns will also easily fall into a routine of taking small feeds and short naps all day (AKA snacking and snoozing), this can be avoided by following an eat, play sleep routine and encouraging full feeds at each feeding.
Tried all of these tips and baby still taking 30-minute naps? Leave it! It can be normal for babies to take 30-minute naps until between the ages of 4-6 months when sleep starts to consolidate.
4-12 month olds
As previously mentioned, it can be normal for naps to be 30-minutes in length until between ages 4-6 months, if you've tried everything and nothing seems to be changing, leave it be! IF naps are still short, you can take a look at a few things.
What are the wake windows you're following? Keeping your baby up long enough between naps plays a huge factor in how long they will nap for. By 5 months most babies need to be awake for 2.5 hours between naps and by 7 months it's 3 hours. Play around with their awake times to see if you can increase naps.
How are they falling asleep? If you're helping baby to sleep, then sneaking away once they're sleeping, they will often wake up looking for you. This can disrupt the entire nap and make it difficult to go back to sleep. Work on some independent sleep skills to solve this issue.
30-minute naps have their time and place, especially nearing nap transitions. When babies are nearing a nap transition, we want to make sure they're not getting too much sleep while we wait for them to be able to stay awake long enough to drop one of their naps. Utilize a 30-minute (or sometimes less) nap in this scenario to help get them to bedtime without relieving too much sleep pressure!
Lastly...
You should know, that if a baby does a 30-minute nap, while it may seem 'short' and we often even call it 'short', it really isn't that short of a nap and they should still do their full wake window until their next nap.
Hope this helps!
That Sleep Mama