A nine-month-old infant is brought to the pediatrician by her mother for a routine well child visit. The patient’s mother has no current concerns about the infant’s health. The prenatal and birth history are unremarkable. Past medical history is significant for poor weight gain in the first month of life which resolved with formula supplementation in addition to breastfeeding. Developmental milestones were normal for age at the 6-month well child visit. Vital signs are within normal range. Physical examination reveals an alert infant who is sitting in her mother’s lap. There are no abnormalities noted on physical examination.
Which of the following new developmental milestones has most likely developed since the patient’s last visit at six months of age?
The correct answer is:
E) Uses “Dada” or “Mama” nonspecifically
This is one of the verbal language milestones typically achieved around nine months of age. Other nine-month milestones include using basic gestures (e.g., waving bye-bye), pulling to stand, and picking up food to eat.
Answer choice A: Babbles sounds like “ga” and “ma”, is incorrect. This is a verbal language skill usually developed at six months of age.
Answer choice B: Identifies at least two body parts, is incorrect. This is a verbal language skill usually developed at 18 months of age.
Answer choice C: Keeps head steady when held in a sitting position, is incorrect. This is a gross motor skill usually developed at two months of age and would not be a new milestone achieved between six and nine months of age.
Answer choice D: Squats to pick up an object, is incorrect. This is a gross motor skill usually developed at 15 months of age.
Key Learning Point
Verbal milestones at nine months of age include using “Dada” or “Mama” nonspecifically, looking around in response to cues like “where is your bottle”, and copying sounds that parents make.
