You can relax and continue to breastfeed on demand, good for you by the way! From Kellymom : A note about growth charts A growth chart isn't a test, where you are striving to get your baby into the 100th percentile. The growth charts show us the statistical distribution of weight, height , etc. in a particular set of babies (or children or adults). So if a baby is in the 50th percentile for weight on the CDC charts, it means that half of the babies of the same age in the US are heavier and half are lighter; if a baby is in the 10th percentile for height, then 90% of babies of the same age in the US are taller and 10% are shorter. Healthy babies, just like adults, can come in all shapes and sizes - a baby in the 3rd percentile can be just as healthy and normal as a baby in the 97th percentile. What doctors are generally looking for on a growth chart is that baby stay relatively consistent in their growth pattern (see below for why this may not happen with the current growth charts). Growth charts are only one part of the puzzle, however, and must be evaluated along with other factors, including: What size are baby's parents? What were their growth patterns as babies? What about baby's siblings or other family members? Genetics plays a large part in baby's size, so don't ignore it. Is baby gaining consistently, even if it's not on a curve? Is baby meeting developmental milestones on or near target? Is baby alert, happy, active? Is baby showing other signs of adequate milk intake? Growth charts and breastfed baby growth I have heard of many breastfed babies (including my own) whose doctor was disturbed at some point because the baby wasn't gaining weight quickly enough, even though the baby was well within the above parameters for weight gain. The problem is that many doctors are not familiar with the normal weight gain patterns of breastfed babies, and rely too much upon standard growth charts. Healthy breastfed infants tend to grow more rapidly than formula-fed infants in the first 2-3 months of life and less rapidly from 3 to 12 months. All growth charts available at this time include data from infants who were not exclusively breastfed for the first 6 months (includes formula-fed infants and those starting solids before the recommended 6 months). Because many doctors are not aware of this, they see the baby dropping in percentiles on the growth chart and often come to the faulty conclusion that the baby is not growing adequately. At this point they often recommend that the mother (unnecessarily) supplement with formula or solids, and sometimes recommend that they stop breastfeeding altogether. Even if mom realizes that her baby is perfectly healthy and doesn't follow these unnecessary recommendations, she ends up worrying for no reason (and moms don't need anything extra to worry about!).