The pattern comes in a variety of sizes and I decided to go for the 3-6 month but having faithfully following the instructions it's turned out to be yet another preemie sized one. It measures a little over 12 inches round the chest.
It's unusual and just a bit different as the buttons are set slightly off-centre to make room for the pattern panel on the right front. There is a narrow twisted rib on the edges of the waist, neck and sleeves. The 4 small deeper pink buttons show my bit for recycling, they are from the t-shirt top I threw out a few weeks back, perfect size for this though.