The large and small fontanelles, which are commonly referred to as the baby’s posterior and anterior fontanelles, are located in the middle of the toddler’s skull, with 11 o’clock and 5 o’clock being the specific locations where the large and small fontanelles are located. In an ultrasound, to make it easier to describe, a circle is drawn between the pubic symphysis and the vagina, arranged according to the 12 time points of a clock, with 12 o’clock at the bottom and 6 o’clock at the top, and the exact location of where the large and small fetal fontanelles are located are described in this order of time points. The large fontanelle is at 11 o’clock, which is the posterior occipital position.