One of the formula companies distributes a premie growth chart. It's adapted from BabsonSG & Benda GI: Growth graphs for the clinical asssessment of infants of varying gestational age. _J Pediatr 89:814-820, 1976. You could also go back to any texts you may have access to that have info about fetal development. The concept of "adjusted age" is very useful in dealing with premie growth and development. Take the number of weeks the baby was early away from the normal expected gestation at birth (40 weeks). Now you have a "xx weeker." Then you begin to add back on the number of weeks since the birth to get adjusted age. For example, a baby who was born 6 weeks early (34 weeker) who is now 2 weeks old would be 36 weeks adjusted age (expected to be the size and developmental equivalent of a baby who is 36 weeks or 4 weeks premature still). By the time that same baby is 10 weeks old, we'd expect about typical 1 month old size and capabilities. In years of working and teaching about premies, i've found there's no rule about how long you have to deal with "adjusted age". A few years ago, when survival was not expected before 27-28 weeks, many babies were caught up to their chronoligical age (ie. had made up for being premie) by 2-3 years. Now, with babies surviving who were 15 weeks early/ 25 weekers, I expect it takes them longer. And those who are only a few weeks early (less than 6), you might not be able to tell by the end of the first 6-12 mos. HOWEVER, and this is the big issue: it really depends alot on why they were premie and what happened to them biologically/medically during the initial recovery weeks. Babies who were sicker or SGA and premie tend to have a harder time recovering. Premies and development are some of my favorite topics, can ya tell?!- -Phyl