Infant Growth and Development: The term “infant” is applied to children within the age range from birth to 1 year. During this first year, there is immense growth. Infants progress from total dependence to engaged interaction, play, and movement. The following information is applicable to full term babies without other health or medical concerns. Children with slow or poor weight gain, particularly in diagnoses of failure to thrive, will likely have a slower growth and development and will find that their developmental milestones will be delayed or postponed until weight gain and infant intake is regulated. Being medically healthy contributes to a more traditional and successful course of growth and development. Breastfeeding supports this, while formula feeding can place infants at an increased risk for numerous medical illnesses or conditions, including GI and respiratory
diseases, urinary tract infections, and lower neurological function. 1 INITIAL FEEDINGS: The first month of life provides the most dramatic change in quantity of breastmilk consumed per day. On the first day of life in a breastfed infant, consumption of an average amount of 30 ml breastmilk per day is typical. By the end of the first month of life, average intake increases to 750 ml or more breastmilk per day. In a breastfed baby, intake of milk stays relatively stable from 1-6 months, whereas in formula-fed babies, intake is more variable and generally increases over time. Once solid foods are introduced at 6 months of age, a slight decrease in breastmilk consumption happens as solid foods start to take its place. FEEDING PATTERNS: Mothers in western cultures are encouraged to regulate infant’s feeding patterns according to the clock, feeding no more often than every 2 hours. Mothers in other cultures will breastfeed on demand for the whole course of breastfeeding, which directly impacts the amount of milk consumed, generally leading to more consistent and robust weight gain in the infant. During the first 6 weeks of life, feedings are often more frequent in the evening hours. After the initial 6 weeks, babies generally decrease the time they spend feeding due to increases inefficiency and stomach size. MILESTONES: In the first 2 months of age, infants are engaging with individuals in their environment, looking with intention, smiling responsively, and showing joy and calm when in the presence of someone safe and known. Other sounds emerge along with a reaction to the noises in the environment. Two-month-olds will hold their attention on an object or family member as they move. Head control improves and simultaneous movement of arms and legs occur. From 2-4 months of age, infants smile to draw attention, begin to learn to laugh, and learn to get attention through sound and movement. Cooing begins, responsive sounds occur, and noises are followed. Infants show preparation to feed with reaction to the bottle or breast. Hands and arms become more engaged, hand-sucking and swinging arm motions are common, and toys can be kept in their grasp. Head control is stable, and infants can push up onto their forearms from their stomach. Three-months-olds commonly become distracted while feeding as they become more observant of the world around them. Often, infants will feed either in more frequent intervals or during longer sessions at night to make up for the milk not consumed during the daytime. From 4-6 months of age, infants better recognize people in their daily life. Mirrors are attractive,
and laughter is fully exhibited. At this age, babies make responsive noises, squeal, and blow bubbles with their spit (raspberries). They establish how to grasp and suck on more objects and roll from tummy to back. While in tummy time, 4-month-olds can push their arms straight to support them. They begin to learn supported sitting, using their arms to hold them in place as they begin to be more upright. Between 6-9 months of age, infants can start having hesitancy with strangers, crying and reaching for loved ones after goodbyes. They signal with lifted arms to show they want to be picked up. More expressive emotions can be seen, including happy, sad, angry, or startled. Name recognition and games begin, such as peek-a-boo and banging objects together. Between 4-9 months, infants learn to sit unsupported. 1 A 9-month-old may begin making “ma” or “ba” sounds. Object permanence begins, and infants start looking for things that are out of sight. Infants can pass items between hands and can pull objects towards them in a “raking” motion. Crawling begins in many infants at this age, but can occur anywhere between 5-14months. From 10 months-1 year of age, infants enjoy games like pat-a-cake. Speaking truly begins, with words like “bye-bye,” “mama,” “dada,” or other familiar names being common. Comprehension grows, such as understanding “no.” Infants at this age like to put things into containers and look for hidden toys. Pulling up to stand often occurs around 10 months but can be possible between 5-12 months. Cruising along furniture is common at this age but can occur between 6-14 months. 1 Standing independently can occur between 6-17 months. In most children, walking occurs at a year of age but can occur anywhere between 8-18 months. 1 A 1-year-old can drink from an open cup and apply a pincer grasp between thumb and pointer finger to pick things up. By age 1-year-old, your child has exited infancy and entered toddlerhood. WEANING: The American Academy of Pediatrics recommends a minimum of 6 months of exclusive breastfeeding, followed by the introduction of complementary foods given alongside continued breastfeeding. The World Health Organization recommends a minimum of 2 years of breastfeeding prior to weaning. Delaying weaning can provide positive health protections to the infant including less obesity, diabetes, allergies, and childhood cancers, among others, contributing to a more positive, developmental trajectory and healthy growing baby. Citations:1 Mannel, Martens, Walker. Core Curriculum for Lactation Consultant Practice. 3rd ed. Burlington, MA: Jones & Barlett Learning; 2013. National Center on Birth Defects and Developmental Disabilities. Centers for Disease Control. Important Milestones. Published August 2022. Accessed September 20, 2022. https://
www.cdc.gov/ncbddd/actearly/milestones/milestones-1yr.html.