She is also alarmed that women have been demoted, disciplined or sacked for having a baby.

In conjunction with the Equal Opportunities Commission in Scotland, Ms Glen, who sits on the Scottish Parliament’s equal opportunities committee, has uncovered the worrying figures.

During the period 1997-2004, a total of 441 cases alleging unfair dismissal on the grounds of pregnancy, childbirth or maternity were registered with Employment Tribunals in Scotland.

Of the 441 cases lodged, 135 were successful, which included unfair dismissal on the grounds of failure to allow time off for ante-natal care, failure to allow maternity leave or provide written reasons for dismissal to an employee who is pregnant or on maternity leave, failure to pay remuneration whilst suspended from work for health and safety reasons whilst pregnant or on maternity leave.

In a motion submitted to the Scottish Parliament, Ms Glen calls on the Scottish Executive and the UK government to act upon the findings of the investigation to put a stop to pregnancy discrimination.

“At least one mother every month in every year since 1997 has been found by an Employment Tribunal in Scotland to have been unfairly dismissed from their job on the grounds of pregnancy, childbirth or maternity,” said Ms Glen.

“Today, it might have been thought that these attitudes towards pregnancy belonged to an unenlightened era that had been left behind.

“It is disgraceful that this is not the case.

“The Equal Opportunities Commission has already stated that the most frequently-received calls on their helpline deal with women facing employment problems because they are pregnant.

“Scottish industry and commerce require the skills and expertise of women at work just as much after pregnancy as they do before pregnancy.

“Women should not fear that childbirth puts their job or their position at work at risk.”