In this paper I examine the evolving association between educational attain
ment and the timing of births. In the late 1970s, women with four-year coll
ege degrees had lower first birth rates before age 30 than women with less
education, but rates of first births were similar for the two groups after
age 30, From the 1970s to the 1990s, first birth rates decreased before age
30 for all women but increased after age 30 only for women with four-year
college degrees. Parity 2 birth rates also increased for college graduates
with a first birth after age 30. These results document widening educationa
l differences in fertility timing between 1975 and 1995, which may reflect
period changes at later ages in women's work and family lives.