Nearly half of American female scientists give up full-time research work after giving birth to one child.

A study on how having children in the United States affects career development shows that more than 40% of women who work full-time in science leave their department or take part-time jobs after giving birth to their first child.

In contrast, only 23% of new fathers left their jobs or shortened their working hours.

The analysis, led by Erin Cech, a sociologist at the University of Michigan at ann arbor, may help explain the continuing underrepresentation of women in careers involving science, technology, engineering and mathematics ( STEM ).

Cech said the study also highlighted the influence of father’s role on the scientific profession.

Considering that 90% of Americans become parents while working, Cech and university of California, San Diego sociologist Mary Blair-Loy want to better understand what their career has experienced since scientists started to set up families.

Cech and Blair-Loy used a statistical data system of scientists and engineers.

This is a database provided by the National Science Foundation of the United States, which contains information from the STEM Labor Force Survey conducted every two or three years.

The two selected full-time scientists with no children from the 2003 data and tracked their family status in the next survey ( 2006 ).

This gave Cech and Blair-Loy two groups of scientists to compare: 841 scientists who became parents at this stage, and 3365 scientists who still have no children.

The researchers also analyzed what changes these people experienced in their career from 2003 to 2010.

They report that novice parents are more likely to give up full-time work in science and choose full-time work unrelated to science than colleagues without children.

By the end of this research phase, 23% of men and 43% of women who became parents had given up full-time STEM work.

They will choose to take part-time jobs, switch to jobs unrelated to STEM or not work at all. Among male and female scientists who have no children, the proportion is 16% and 24%.

For those who leave the scientific community, the data set also contains information on why they left. About half of novice parents cited family-related reasons, while for those without children, the proportion was only 4%.

The team said that taken together, these findings show that parenthood is an important driver of STEM’s gender imbalance in employment.