I don’t understand what “STEM representation” is.

Although Oppression, discrimination and bias are all important factors for lack of representation in STEM, there are also many other important factors

• Factors such as inaccessible childcare also contribute to unequal STEM representation. Childcare costs are astronomical, with the average cost of day-care in London £280 a week which is £14,560 a year for one child. As a result many women with children may be forced out, or deterred from STEM careers. STEM jobs are very time intensive so therefore mean very expensive day-care costs, this may force many women with children out of the STEM field as day-care may be too expensive and it may be a financial move to instead leave their job or switch careers to look after the child themselves. Although this can also affect fathers, studies show that women on average do more unpaid childcare than men
  In addition, studies have found that women are more likely to leave their job or cut hours after becoming a parent than men.
• This is because STEM careers are very time and mentally intensive, statistics show that "43% of women leave full-time STEM employment after their first child.". This is an issue which also affects fathers in STEM jobs however to a lesser extent "23% of new fathers also leave STEM after their first child".
• Lack of representation breeds more lack of representation, so the unequal representation of women in STEM, only 24% of the STEM workforce are women as there is a lack of female STEM role models and the gender inequality can breed a male-dominated STEM culture which can put women off STEM careers
• More flexible jobs, universal childcare and ensuring STEM mentors and support for girls and women

I doubt that they even contribute to the disparities at all. Men and women are different, it's not rocket science. Given the free will to chose their own path in life, men and women will make different choices.

So long as they all have the same opportunity to pursue a career (outside of the military of course) then the demographic outcome is irrelevant.