A new research from the Washington University in St. Louis suggests that career women who want to minimize their earnings losses when it comes to having kids should wait until they turn 30.

Man Yee Leung, PhD, a postdoctoral research associate at WU School of Medicine explains that the findings highlight the upsides and downsides of women when it comes to starting a family and a career. Their focus was to "...look at total labor income from ages 25 to 60 as it relates to a woman's age when she has her first baby," says Leung. Science Daily has it that children can somehow affect the potential career trajectory of their newly experienced mothers.

Raul Santaeulalia-Llopis, an assistant professor of economics in Arts & Sciences at WU explains, "Children do not kill careers, but the earlier children arrive the more their mother's income suffers. There is a clear incentive for delaying."

The study found that mothers incur losses in their income between 2 and 2.5 years when they have their first kid at 25 years old. However, there are two highlights found from the study:

1. College-educated women who delay having their first children until after age 31 earn more over their entire careers than women with no children.

2. Noncollege-educated women who give birth after age 28 experience a short-term loss in income but eventually catch up with the lifetime earnings of women who have no children.

Although the researchers data and trends come from women's fertility and career choices, nowadays it is evident that women are delaying their motherhood to a later part in life.

The study ends with Santaeulalia-Llopis explaining that the fact that highly productive women who have children earlier enter a lower income path is not only a loss for them, but for the entire society too.

He suggests that if women think that children are hindering their careers then companies should think about employer-covered fertility treatments.