From the Guidelines
At 9 months, babies typically achieve several important developmental milestones, including sitting without support, crawling, pulling themselves up to stand, and using a pincer grasp to pick up small objects, as outlined in the most recent and highest quality study 1. These milestones are crucial for assessing the developmental progress of a 9-month-old baby. According to the study, at 9 months, babies should be able to:
- Roll over supine to prone
- Sit without support
- Pull to stand
- Come to sit from lying
- Crawl
- Reach for cubes and transfer them
- Rake small objects with 4 fingers
- Pick up small objects with 3 fingers It is essential to note that these milestones represent average development, and there is a normal range of variation. Some babies may achieve certain skills earlier or later. If a baby isn't sitting independently, showing interest in moving around, making sounds, or interacting socially by 9 months, parents should discuss these concerns with their pediatrician, as early intervention for developmental delays is most effective, as recommended by the American Academy of Pediatrics 1. Key elements of a motor history, such as delayed acquisition of skills, involuntary movements, or regression of skills, should be considered when assessing a 9-month-old baby's development 1. A physical examination should also be performed to consider congenital myopathies or lower motor neuron disorders, and to assess the baby's overall developmental progress 1.
From the Research
Developmental Milestones for 9-Month Well Babies
At 9 months, well babies are expected to achieve certain developmental milestones. These milestones can be categorized into several domains, including:
- Gross Motor: abilities such as crawling, sitting, and standing with support 2
- Fine Motor: skills like grasping and manipulating objects 2
- Cognitive: abilities such as problem-solving and understanding object permanence 2, 3
- Language Comprehension: understanding simple words and phrases 2
- Speech: babbling and making cooing sounds 2
- Social: interacting with others, such as smiling and laughing 2
- Emotional: exhibiting emotions like happiness and frustration 2
- Regulation: self-soothing and regulating emotions 2
Expected Milestones
According to the study by 2, parents of 9-month-old babies track a median of 5 milestones per diary, with the most common domains being Gross Motor, Fine Motor, Cognitive, and Social. The study by 3 found that extremely preterm infants increased their Motor Object Exploration (MOE) duration from 6 to 9 months, eliminating the initial difference with full-term infants.
Importance of Tracking Developmental Milestones
Tracking developmental milestones is crucial for early detection of developmental delays and appropriate referrals to early intervention 4. The study by 5 found that identifying predictors for developmental pathways can inform early intervention services, and that infants with low gestational age, low Apgar score, male sex, and a mother with depression symptoms or non-Scandinavian ethnicity may be at risk of developing less beneficial developmental pathways.
Long-Term Implications
The study by 6 found that infants who reached developmental milestones sooner in their first year of life had significantly better mean scores in teacher ratings at 16 years and were more likely to achieve a better educational level at 31 years. This suggests that achieving developmental milestones on time may have long-term implications for educational attainment and overall development.