New research shows very few women leave top jobs to have children - and it is a needless gender barrier that keeps many out of careers in science, technology, engineering and mathematics.

A study in the United States has tried to gauge the reasons for a lack of women working in the so-called 'STEM' (science, technology, engineering and mathematics) fields. Researchers at the University of Texas-Austin and Cornell University found little evidence that women are opting out of the STEM workforce to start families, in contrast to the widespread perception.

The findings strongly suggested that women who get degrees and are employed in STEM positions often leave these jobs to work in other sectors. The study says finding the key to retaining females in STEM jobs will help improve numbers for the field in the long term.

“While in other professions pursuing an advanced degree and viewing one's job as rewarding tend to increase retention, such investments made by women in STEM do not seem to stimulate commitment to STEM in the same way,” study co-author Professor Sharon Sassler says,

“Gender barriers are hindering women from entering into STEM jobs, and even among those women persistent enough to enter the STEM labour force, transitions out of STEM jobs transpire relatively early on in their careers... our work indicates that a substantial proportion of women who are trained in STEM, and begin working in STEM jobs, rapidly exit such jobs.

“Additional attention is needed to the field of STEM itself to better understand why so many of the highly skilled workers trained -at great expense - for these fields are exiting,” Prof Sassler said.

The study has been published online, but can only be accessed via subscription to Oxford Journals.