One of the most fun parts of parenting a baby is being able to shop for baby clothes. They’re all so cute. And the pajamas are absolutely adorable. We don’t know about you, but we wish they made them like that for adults.

Cuteness aside, though, there are some sleeping clothes which are better for babies than others. If you’re like most parents, you want to help your baby to sleep as soundly as she possibly can. The last thing you want is to have a pair of pajamas (no matter how cute they are) irritating your baby and waking her up.

When it’s hot outside, many babies enjoy sleeping either in a diaper or in a onesie. If you use a blanket, make sure that it is tucked in snugly and that it doesn’t have ribbons, buttons or holes for baby to get fingers caught in.

As it gets cooler, of course, you should put your baby in some kind of pajamas. Generally speaking, one piece pajamas as more comfortable for sleeping than two piece pajama sets. With two piece sets, the bottom of the shirt and top of the pants can irritate baby’s skin, especially if they have an elastic waistband.

Regardless of which style of pajamas you put on your baby, tough, you should look for outfits made of very breathable materials, such as cotton. Many synthetic materials keep the air from circulating, and don’t allow baby’s skin to breath. This can lead to irritation or ever a rash. The bottom line is that it can be uncomfortable and make it harder for baby to sleep as soundly.

Many parents now use a sleep sack, especially for younger babies. This is essentially a blanket which the baby wears. It resembles a small sleeping bag, except that it fastens up loosely around baby’s neck. It allows baby to move around as much as she likes (and is able to) while ensuring that she stays snug and warm.

Sleep sacks can be used with or without other pajamas, depending on how warm it is. Many parents simply put baby in the sleep sack wearing a onesie.

One of the major advantages of sleep sacks is that they help prevent babies from flipping over onto their stomachs. Sleeping on the stomach is a well known cause of SIDS. While most doctors don’t recommend flipping baby back over if she flips over herself (you’ll just wake her up and make it difficult for her to get needed rest), using the sleep sack is a safe way to stave that off a couple more months.