gerber onsies don't fit true to size!
My son had just moved up from size 9 months to 12 months and bought him some gerber onesies (had never purchased, stuck to carters onesies previously). These onsies shrunk slightly during after washing (I washed cold/delicate and dried on delicate but it recommends warm and medium) but it was smaller than a nine month after wash. I liked that these were light-weight, but their sizing chart is ridiculous. I guess if you need a 12 month onsies, buy a 18 month or even 24 month/2T.

I think you give me a wrong size.
I think maybe the sender might give me a wrong size because I also bought Gerber long sleeve (6-9). Comparing with those products, the 18 month clothing is only a little bit bigger than the long sleeve one.

Gerber baby underwear
You have to buy it, there are so nice and confortable.

I bought from newborn to 6 months, and I can tell I love them

Compare to other brands and can notice they have good quality for the price.

Worst Item ever bought
I ordered size 6-9months for my son to be worn during summers. The size is so small that it does not fit him now at 3 months. Also, the quality of cloth is much worse than what you get @ carter/baby store for the same price. They are selling cheap stuff that is sold in other countries for the same or more price than you can find here. I would NOT recommend to buy this item. I would rather pay taxes in California than buying kids clothing again from the site. Very very disappointed at Amazon. I would rate it at 0 star but it won't let me do that otherwise.

Gerber onesies sizing tip
These onesies are "true to size" IF:

1. your child is small for his/her age, AND
2. you wash in cold water and always line-dry, never machine-dry them, to prevent shrinkage.

Example: my 18mo daughter is petite in weight at just over 22lb. She is a little over 30in tall, so she's in the correct height range for 18mo according to the onesies package. The unshrunk 18mo onesies, which on the package say will fit 24-28lb, fit her like a glove both in length and width.

This particular set is VERY cute - love the prints, embroidered designs, and colors. It's been fun to be able to dress a little girl in onesies after 4 boys in a row (spanning 15 years in age). And yes, the other reviewers are right, Gerber's sizing has changed. The old-style serged-sleeve onesies were much roomier in length/width than the new ones are. The old size M (19-26 lb) onesies are BIG compared to these, and that's even after taking shrinkage into account.