I also have found that preterm babies can breastfeed at extremely young gestational ages . The criteria of no ventilator or cpap being used, and not fragile are good indicators of when a baby is ready to begin at the breast. Waiting until 33 weeks sometimes makes eager babies miss out on some wonderful experiences( and beneficial, nutrition-wise). I have seen many 30 week babies and a few younger do quite nicely at the breast. Fritzi Drosten, RN, IBCLC Piedmont, CA USA