A child's growth early in development will dictate much about his or her.

A new study indicates that if a baby puts on 40 percent or more of their birthweight in their first month of life, they will have a higher IQ than babies who put on 15 percent or less of their birthweight in their first month after birth.

Part of this depends on the growth of their heads. When babies gained much of their weight in the first month of life, their head circumferences were also larger. A larger skull size allows the brain more room for growth and development. Lisa Smithers, Ph.D., leader of this study, explained, "Head circumference is an indicator of brain volume, so a greater increase in head circumference in a newborn baby suggests more rapid brain growth." If the brain is allowed to develop soon after birth, it is likely that by the age of six, which is when IQ scores were measured in this study, their brains would be more developed.

These children were given IQ tests at the age of 6.5 years. Those whose heads had a larger circumference and who had gained much of their weight in the first month of life had IQ scores 1.5 points higher than counterparts who had not gained as much weight. "Those children who gained the most weight scored especially high on verbal IQ at age 6. This may be because the neural structures for verbal IQ develop earlier in life, which means the rapid weight gain during that neonatal period could be having a direct cognitive benefit for the child," said Smithers.

Although babies may not always have great appetites. TheBump.com, a leader among women's websites, reports that babies grow fastest in their first six months of life. However, in that same time, an infant's digestive system is not fully developed. As a result, he or she may lose up to 10 percent of body weight in the first days of life, according to Livestrong, as he or she adjusts to using the digestive system. As a result, digestive upsets that are common in young children, like frequent spitting up and vomiting, can occur, but should not alarm parents too much. Because newborns' stomachs are small and because they don't have the intestines to absorb nutrients effectively, infants need frequent feedings in order to allow for adequate growth and development. But breast milk is high in fat; consumed in small portions, however, breast milk can be an effective way to give newborns sufficient nutrients for growth and development.

Smithers said her findings highlight the need for effective feeding in the first month of an infant's life. She admits that many mothers have difficulty establishing a breast feeding schedule, or even having their children glean any milk from her breast, in the first month after birth. However, Smithers said immediate steps must be put into place to ensure that a child gets all the right nutrients in the first month of life. While the study did not show any deleterious effects in infants who failed to gain much of their weight in the first month, if these children are put at a disadvantage, parents should do everything in their power to ensure all the best opportunities for their children, especially in those first 30 days.

Source: Smithers LG, Lynch JW, Yang S, Dahhou M, Kramer MS. Impact of Neotnatal Growth on IQ and Behavior at Early School Age. Pediatrics. 2013.