I first came across the idea of “fertility privilege” in a podcast by the author Elizabeth Day, who has been admirably open about her desperate desire to be a mother after repeat miscarriages and fertility treatment. The podcast made me cry, though Day would be well within her rights to tell me to stuff my tears, because I got my baby. I joined the club. I have what she terms “fertility privilege”, ie I have conceived and carried a child without too much difficulty.

In an article that caused something of a furore, Day wrote: “We rightly talk about privilege in this era of social change – an era marked by Black Lives Matter and #MeToo – but hardly anyone acknowledges fertility privilege. Those of us who have had complicated journeys to parenthood are only too aware of its existence. … I know how it feels to be the infertile one in a world of apparent abundance. I wouldn’t post about my glorious babies on social media in much the same way as I wouldn’t post about my expansive mansion or my fleet of Bentleys (not that I have any of those), because it’s thoughtless to those who don’t have these things.”

There can be a certain self-satisfaction to motherhood, as reflected in the photographs we post and the things we say to each other when childless women aren’t present (not to mention the thoughtless things we can say when they are). Many mothers are mindful of their good fortune that their children are here and – by the grace of God – safe and well. There is a feeling of relief, of being smiled on by biology. There is, of course, the boundless love which can seem all consuming and can manifest as exclusivity.

Those living with infertility seem to more commonly embrace the concept of fertility privilege, or feel acknowledged by it; the author Jennie Agg has written movingly on the complacency she encountered around pregnancy as she endured repeat miscarriages. Many women with children also expressed admiration for the term as a way of vocalising how lucky they felt to easily conceive.

More, though, found it a divisive term or felt it lacked nuance. Many mothers have also experienced miscarriage and fertility issues. Fertility privilege arguably flattens the experience of pregnancy and childbirth, which can be fraught with difficulty. One woman who has struggled with infertility writes to me that the comparison with material luxuries is inappropriate – after all, children aren’t commodities and most people have them. She compares all the #blessed posts on social media to sharing pictures of abundant food when we know others live with food insecurity.

Mothers already feel as though they aren’t granted the space they need to speak openly: that they must tiptoe around. “It seems like sometimes we need to apologise for being mothers and aren’t allowed space to talk honestly about the ups and downs without sugarcoating it so much it becomes meaningless,” one told me. “Talk of privilege feels so inappropriate and lacking in empathy,” says another, who is struggling after a traumatic birth. “Mothers simply cannot condemn themselves to any more guilt than we are already socially conditioned to endure. We are maxed out,” says another.

I struggle with the idea that whether an egg becomes fertilised or not – a lottery – should carry moral implications. Fertility is not structural or fixed – it changes month by month or year by year. “Fertility can be the opposite of desirable for a lot of people – who really don’t want to get pregnant. It can be a burden or a threat to them,” writes one woman, who says she had periods of “hyperfertility” that resulted in two abortions. Another highlights victims of rape who become pregnant. “Being fertile doesn’t mean the end of the story,” says a mother who had two healthy children but was then diagnosed with cancer.

Furthermore, talk of fertility privilege is in itself synonymous with a certain background; these are often middle-class women usually talking about other middle-class women. That is not to deny their pain, but to be fertile and working class, on benefits or a teenager is not culturally prized in the same way. It is actively condemned. Pregnancy and childbirth often lead to discrimination and marginalisation.

Still, I admire Day’s attempts to widen the language around miscarriage, infertility and not-motherhood. To quote the poet Sandeep Parmar: “Taxonomies of grief elude the non-mother, the unmothered, the-anything-but-this-fact.” There is so much hidden pain, apparent to anyone who has looked at fertility forums.

As one reader reflected, getting pregnant after a year and a successful course of treatment would be considered “privileged” to others. Some forum users who have never become pregnant will intimate that even a woman undergoing the trauma of repeat miscarriage is somehow “lucky”, because she can “at least get pregnant”. Many of these emotions are raw and ugly, which is why people shy away from discussing them face to face. Day’s radical honesty opens up the conversation.

There is so much more at play, though, when it comes to having children, than mere biology. “I’m not sure that I feel as privileged in my fertility as I do in the complicated intertwining of privileges which allowed me to have them (being in a heterosexual relationship, finding someone who agreed to have children earlier than they planned, the financial stability to do so, a strong familial support network),” says a woman who had children young because of endometriosis. I do wonder where it all ends: do those with female bodies have fertility privilege above gay men? What about those who can afford fertility treatment, even if it is ultimately unsuccessful?

And what of single women? Reading Amy Key’s Arrangements in Blue, a beautiful memoir about a life lived without romantic love, I am moved by her descriptions of longing for a child, her lack of bitterness and generosity to those in her life who have what she so craved. That is not to say that to be bitter is inappropriate – too often women are told to mask these difficult emotions. More that Key seems less interested in the privileges that divide us than in the forms of love that can unite us, whatever they may be, and expand our understanding of what it means to have a life well lived, fostering solidarity between all women, whatever our journeys.

What’s working
The baby had his first taste of proper wood-fired thin crust pizza at the weekend. He’s already a fan of the good ricotta from our local deli. We have yet to travel abroad, but I’m now considering Italy.

What’s not
I have yet to find a nappy that can last the whole night through. If you know of one, please send recommendations my way. It’s often the last thing standing between me and a full night’s sleep.

• Rhiannon Lucy Cosslett is a Guardian columnist