Under current guidelines couples must lose three babies before being offered tests to find out what might be causing them problems.
Scottish Care and Information on Miscarriage has submitted a petition calling for sufferers to be offered tests after one miscarriage.
In its submission to the Public Petitions Committee, it described the current scenario as "inexplicable".
The NHS follows guidance issued by the Royal College of Obstetricians and Gynaecologists when caring for couples who have suffered miscarriages.
Their experts have argued in the past that testing earlier would only pick up health problems in a very small number of cases and would cause some couples unnecessary anxiety..