Recently my mother told me about an encounter she’d had with one of my former primary school teachers. As is often the case with her, it involved an inordinate amount of boasting:

"I told him about all your degrees and your job and he said 'ooh, I always knew she was clever', but I told him it was alright because you’d still had children and were normal."

At the time it made me laugh. God forbid a woman having too many degrees to be “normal”! All the same, I knew exactly what she meant and why she had said it. She needed to reassure people that I hadn’t turned into one of “those” women; I hadn’t let university go to my head and forgotten my essential function. I can laugh all I want, but part of me knows that this matters. Like it or not, I am judged on my reproductive worth and I have not been found wanting.

In that respect, even though I lack the money, fame and status, I have one over on the likes of Jennifer Aniston and Kylie Minogue. Poor them! All of that success and yet they forgot the basics! Aniston can protest all she likes – claiming to have “birthed” and “mothered” many other projects – but she will still be looked upon as having “failed”. As the Observer’s Barbara Ellen writes in response to Aniston’s recent defence of her child-free status, “childless women, particularly as they mature past childbearing age, find themselves dismissed as redundant, withering, lacking”. As a mother, I can of course choose to feel smug, seeing it as payback for all those sleepless nights and dirty nappies; for once, I win! Yet if I’m honest, such a victory is illusory. In a culture that reduces all women to breeders and non-breeders, how could any of us win?

It’s tempting to pitch this as a tension between mothers and women who have not had children. I think, however, we need to put this in a broader context: that of all women still being judged by their reproductive role, regardless of whether or not they ever bear children. The story of Jennifer Aniston’s “failure” sits alongside countless others in which a woman’s worth is measured by the contents of her womb: the high-achieving executive described only in the press as a “mother of three”; the rape victim denied an abortion because her humanity cannot compete with the potential life inside her; the millions of post-menopausal women who become invisible while their male counterparts grow in stature. We are all judged on our childbearing capacities and whatever we do in practice – whether we have children or not – the fact that we are judged in this way diminishes us.

Radical feminists would argue that patriarchy seeks to control women’s reproductive labour. To many this sounds far-fetched; one might picture women literally being lined up to breed like livestock, something which clearly isn’t happening (although forced marriages and mass rapes could be seen to serve a similar function). In more liberal countries the availability of birth control, coupled with the often dubious claim that abortion is freely available, has been used to argue that women are no longer trapped by their biology. The control of women’s reproductive labour might once have been an issue but now, we are told, it is a thing of the past. Like many, I grew up believing that even if motherhood was limiting, at least a woman could opt out. But as responses to women such as Aniston and Minogue show, you can't.

Mother or not, you are positioned in relation to motherhood. The existence of birth control has not even allowed us to make the choice between being seen as a mother and being seen as an independent person; we can only choose between being seen as a mother and being seen as a non-mother. Either way we are defined by our capacity to produce someone else, someone who may be worth more than us; we are insufficient in and of ourselves.

At the risk of sounding old and mumsy, this is something which I think younger feminists often fail to recognise. It’s a phenomenon which only really kicks in once you've either had children or are perceived to be running out of time in which to do so. When you're young, you might assume no one is judging you as a pre-childbearing female; the truth is, they've already made their assumptions. Your reproductive potential need never be discussed, at least not until you've got pregnant or hit 35 without having done so.

People can live on unspoken prejudice right up until the "truth" of your reproductive destiny has become an unavoidable issue. In the meantime you can deny that perceived childbearing capacity has anything to do with the oppression of women in the twenty-first century, but you would be wrong. It has everything to do with it. This (perhaps actual, perhaps assumed) container inside us - this womb - is seen to offer something that we cannot: humanity. Dehumanised ourselves, we exist merely to carry its potential. There's not enough life in us to say, "no, I don't want this pregnancy, let me be"; not enough life to say, "without children I am already full and complete"; not enough life to say, "post-menopausal, I remain a creative force". Or rather, we say all of these things but we're not being listened to.

The belief that women are, deep down, just walking wombs is all around is, yet it remains difficult for women to challenge it in any united, coherent way. Instead we are pitched against each other. When child-free women argue their case, part of me is anxious and does not want to listen. I worry these women see me as conservative, lacking in independent thought, wholly absorbed in nappies, CBeebies and nothing else. Perhaps in turn such women see me as arrogant, someone who is convinced that the childless cannot know the true meaning of existence (whatever that would be). Yet while having children makes an enormous difference to the practicalities of one’s life, the ideological divide between mothers and non-mothers is largely illusory. When we talk to one another, we find we are still as diverse as ever, all of us held back by a culture which groups us crudely into mummy and non-mummy camps. We must not fall into the trap of dehumanising ourselves just because that is what we have been encouraged to do.

It is absurd that women such as Jennifer Aniston are perceived to have incomplete lives, trailing off into oblivion at the point where it becomes obvious that – shock! – they might never reproduce. Absurd, too, that we can place so high a value on the contents of an abused woman’s womb that we forget to see her humanity at all. As women we need to confront this together. We are not simply the childbearing and the child-free; our stories extend beyond the production or non-production of others. We are complete in our own right and deserve to be viewed as such.