Step 1 : Introduction to the question "What is the average age of a father of a newborn baby in the United States?"
The average age of a father of a newborn in the United States was 30.9 years old, according to a Stanford University report. Researchers analyzed 168,867,480 births -- all the live births reported in the US Centers for Disease Control and Prevention's National Vital Statistics System from 1972 to 2015. Men over the age of 40 make up 9% of all U.S. births (that number more than doubled from 4.1% since 1973), whereas men over the age of 50 account for nearly 1%. The youngest dad for the period studied was just 11 years old, while the oldest was 88.