In-depth reviews guided by a Pediatrician

Thirsties Newborn All in One Review

Itty bitty AIO sized specifically for the first few months of life
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Price:   $19.50 at Amazon
Pros:  Smaller sizing, natural fibers, simple to use
Cons:  non-wicking fabric, short usage period
Manufacturer:   Thirsties
By Abriah Wofford & Juliet Spurrier, MD  ⋅  Sep 2, 2019
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The Skinny

Thirsties makes a wide variety of cloth diapers, and they are trusted to be reliable and durable by many users. Their Newborn All In One is an option created specifically for small infants during the first few months of life when they might not have grown into regular cloth diapers yet. With an all-natural fiber interior and a soft waterproof polyester outer, it will not irritate sensitive newborn skin. This AIO has found the perfect balance between absorbency and bulk for tiny tushes, and we recommend this diaper to anyone looking to use cloth from the very beginning.

Our Analysis and Test Results

Performance Comparison

The Thirsties Newborn All In One is a niche diaper that is perfect for babies from 5-14 lbs. It fills the gap of time when regularly sized cloth diapers are too large, and you may otherwise be using disposables. It is the perfect solution for anyone hoping to use cloth from start to finish and create a minimal amount of waste.


This tiny diaper is meant to be worn by tiny babies and only will capture a tiny amount of urine. To add to this, the inside of the diaper is all-natural fabrics and has no wicking lining. Thus, this Newborn AIO scored near the bottom of the group in our absorbency tests, beating out only a swim diaper. However, we did a second round of testing with a reusable microfleece liner, and the diaper performed relatively well, especially considering its small comparative size.


There's a lot to like about the Thirsties Newborn diaper. It has a double hemp/organic cotton inserts that are attached to the diaper at one end as well as an additional layer sewn into the lining for added absorbency. We like that this allows you to layer the inserts differently depending on your baby's absorbency needs. We love the all-in-one style that makes things easy right from the get-go, there is nothing to snap or fold before you can put the diaper on baby. Laundering aside, it is just as easy to use as any disposable diaper. When it comes to cleaning the diaper, the whole thing can be tossed in the machine to wash and dry, although we recommend line drying all your cloth diaper covers.

The cotton lining covers the inner edge of the gusset  keeping it soft and smooth against baby's legs.
The cotton lining covers the inner edge of the gusset, keeping it soft and smooth against baby's legs.

The best part about this diaper is that it eliminates bulk for little newborns. The smaller cover and thinner inserts give you precisely what you need to handle newborn waste, no more, no less. The soft cotton lining reaches to the outer edge of the single gusset and is cozy against sensitive skin. The outer fabric of the cover is waterproofed polyester and is also very soft as not to cause irritation. It has two snap positions for the rise, and four for the waist, allowing you to adjust the fit for any baby within the weight range. There is only one row of snaps around the waist. While we usually prefer two, this diaper is so small that we can't imagine trying to fit a double row of snaps in this space. We feel that one row is sufficient for this purpose.

The single row of snaps was enough for us to feel like we could get a secure fit on baby.
The single row of snaps was enough for us to feel like we could get a secure fit on baby.


There are a few downsides to buying such a situation-specific diaper. You are likely buying this because you want it to fit a small infant. While it does this job very well, it will only fit a small infant. The max weight for this diaper is 14 lbs, a number which most babies will reach within the first 3-4 months. The small size of these diapers does not mean they cost less. The short usage span means you will have to completely rebuild your stash soon after birth, nearly doubling the cost of putting diapers on your baby.

Not intended to hold as much liquid as we tested it with  the Thirsties Newborn All In One did not perform well in its original test.
After testing with a reusable microfiber liner in place  the absorbency test looked much better.

Also good to keep in mind is that the inserts and lining of the Newborn All In One are natural fibers. Fabric such as this can be a good thing in terms of baby and eco-health, but on the flip side, natural fibers tend to have poor wicking capabilities. To remedy this issue, we recommend purchasing a reusable microfiber liner. We tested this diaper with and without, and above you can see how much of a difference microfiber can make. We must admit that the first result can be somewhat deceiving. We tested all diapers with 100 ml of mock urine no matter what, so we could get an apple to apple comparison between products. The Thirsties Newborn diaper is intended for smaller babies than we were basing our tests on and not meant to hold that much liquid. Even so, the diaper was able to contain all the mock urine during our in-lab testing. With the added microfiber liner, the diaper performed relatively well.

The two hemp and cotton blend inserts have good absorbency but aren't fantastic at wicking.
The two hemp and cotton blend inserts have good absorbency but aren't fantastic at wicking.


Necessity is the mother of invention, and the Thirsties Newborn All In One is a diaper that was born with a specific need in mind. It is built to fit babies during the first few months of life when they are so small that regular-sized cloth diapers would look clownish on them. If you have a strong aversion to using disposable diapers to fill this gap, we suggest giving this niche product a try. It is easy to use and functions well making it a cloth diaper we would use on our babies or recommend to a friend.

Abriah Wofford & Juliet Spurrier, MD