More number of highly educated women in their 30’s or 40’s are having babies now than in the past few decades, says a new study published in Journal of Population Economics. Researchers say that this might be the start of a new trend.

For the study, the researchers analyzed data from two sources; the June Current Population Survey for 1980 to 2008 and the Vital Statistics Birth Data from the National Center for Health Statistics.

“One of the major economic stories of the second half of the 20th century was that highly educated women were working more and having fewer children. It is too early to definitively say that trend is over, but there is no doubt we have seen fertility rise among older, highly educated women,” Bruce Weinberg, professor of economics at Ohio State University and co-author of the study said.

“We don’t have the data in this study to say whether they are opting out of the labor market. But we can say they are increasingly opting for families,” he said.

There have been other studies that have investigated how education levels or employment affects a woman’s decision of having babies. A study published in Maternal and Child Health Journal reports that between 1969 and 1994, the age at which women gave birth to their first child increased from 21 years to 24 years. The proportion of mothers who were in their 30s when they gave birth to their first baby also increased from being 4 percent in 1969 to 21 percent in 1994. Women who had finished 12 years or more of education were most likely to have babies late in life with 45.5 percent of college graduates choosing to be mothers after turning 30.

“For the less educated women, it is more a story about the timing of their fertility. They are having their children earlier now than they used to, but they are not having any more children overall. For the less educated women, it is more a story about the timing of their fertility. They are having their children earlier now than they used to, but they are not having any more children overall,” Weinberg said.

Access to fertility treatment might also be a cause for this trend. Fertility treatments increase chances if multiple births. In the study it was found that multiple birth rates began increasing after 1990. The number of multiple births tripled in highly-educated women above 40 from 1990 to 2006.

“Although our estimates are not exact, it is clear that there was an increase in older women having children even after taking into account the fact that fertility treatments are more accessible and affordable,” Weinberg said.

“Fertility treatments contributed, but it isn’t the only factor.”