By Nicholas Bakalar | The New York Times
A young family in California in 1936. Researchers at Stanford University found that the average age of the father of a newborn in the United States has risen to 30.9. Credit Dorothea Lange, via Library of Congress
New fathers in the United States are getting older.
Researchers at Stanford University reviewed data on 168,867,480 live births from 1972 to 2015, making statistical adjustments for missing paternal records. The average age of the father of a newborn in the United States, the investigators found, has risen to 30.9 from 27.4 in 1972.
Paternal age increased across the country: the oldest fathers lived in the Northeast, and the youngest in the South. There were average age increases across all educational levels, races and ethnicities. The report appears in the journal Human Reproduction.