Baby bodysuits make a useful first layer under pants or a cardigan. The Imps & Elfs striped bodysuit is 100% organic cotton and comes in pink or light grey, with sizes from 0-3 to 9-12 months across the colors. Other labels add more bodysuit styles. Check the fastenings too. They differ by style. For fit, allow enough room through the body for a diaper. The fastenings shouldn't pull when your baby bends their legs. Check the available size in your chosen color before ordering.