Therese Shechter knew as early as high school in Canada that she did not ever want to have children. This should not be a controversial idea. After all, bodily autonomy means that what a woman chooses to do with her own body is her business, or should be.

When she told her mother, a Holocaust survivor who discovered she was pregnant with her after emigrating to Israel from Romania as a political refugee, that she would have to rely on her other daughter for grandchildren, she “took it very calmly," recalls Shechter, “and said, 'Okay, fine'.” Her father, also a survivor from Romania, agreed.

To the director's delight, her sibling did give them grandchildren. “My parents are great grandparents," she says warmly. "So I'm really glad they're getting that experience, even though I wasn't going to give it to them.”

Despite this being accepted at home however, she never told her schoolfriends how she felt about having children. As her eye-opening new documentary, My So-Called Selfish Life, reveals, such a choice in what she calls our “pronatalist world” – which is pro-birth and often regards being a mother as the pinnacle of womanhood – can sometimes elicit alarming reactions.

In the film, choosing not to have children and live “childfree”, as opposed to wanting children but, for whatever reason, not being able to have them and being “childless” (the distinction is “helpful”, says Shechter), brings allegations of selfishness and the assumption that people must hate children. A woman who came out to her in-laws about not wanting to be a mother on the primetime American show 60 Minutes, describes how she was branded perverse by its host. She lost her teaching job and received death threats as a result. Understandably wary of what others might say, Shechter kept quiet. For years.

“I couldn't talk to anyone because it was weird,” she tells me on a Zoom call from New York. “In my high school, with all my girlfriends talking about baby names, you couldn't say, 'Actually, I don't really want children. And I actually don't really think I want to get married [she did eventually], either.' I can't imagine having said that, I wasn't that rebellious. It wasn't until my 30s that I started having these conversations.”

From a young age, girls were effectively being taught how to feel about certain life events. Everyone in Shechter's school read Judy Blume's popular YA novel, 'Are you there God? It's Me, Margaret', about a girl who was “going through her maturation and desperate for her period; desperate for her mother to buy her a bra; these sort of initiations into womanhood.” Being a “slightly late bloomer in the period department”, Shechter says: “I really wanted it, because you want to fit in.”

When it finally happened, she was “briefly excited”. Then reality struck, wittily illustrated in the film by short clips from the coming-of-age horror classic Carrie and Game of Thrones. “I realised what a mess it was, and how painful and nasty. And I thought, 'Wow, and now I can get pregnant.' So there were all these things that I sort of realised were not helping me in any way.”

If her entre into womanhood sounds like a trap, the process that many believe ends it was like a liberation.

“When I went through menopause I was thrilled,” she says. “I spent a life trying not to get pregnant and the idea that I was finally free of that is great.”

She is now thinking of making menopause the subject of her next documentary, expanding the trilogy of I Was A Teenage Feminist, How To Lose Your Virginity, and My So-Called Selfish Life into a quadrilogy.

“Menopause has always been framed as the death of womanhood, that you're kind of done, and you need drugs to make you feel happier and make you be more attractive because of that idea. Of course, as I get older, and as I think about these issues 24 hours a day, it became really clear to me that this is bullshit.”

Shechter “dodged the bullet” of motherhood, but says it is important to understand that there was a time when she assumed that she would have children, because of the prevailing culture. It was just what “everyone did”, she says.

“I didn't have any role models of healthy, happy women who had chosen not to have children, they just did not exist. Except for, maybe, Mary Tyler Moore and Rhoda. So I just assumed I was gonna have kids and I felt like I needed to do everything I wanted to do before that happened, although it was rough trying to figure all that out.

“I feel very clear about everything now. But in my 20s and 30s, I certainly would have not been speaking the way I'm talking now. I would have been very confused, very unsure of what I was able to say. It took a long time for me to get to a place where it's like, 'Oh yeah, this is good.'”

One person she did confide in was her friend, the journalist Anne Kingston (who appears in the film and died before its completion). In 2009, Kingston wrote a story for Maclean's magazine titled The Case Against Having Kids. It received such a “horrendous backlash”, says Shecther, that Kingston suggested she make a film about the subject. “I said I wasn't ready to tackle it beyond private conversations.”

Kingston continued to gently nudge her, and by the time Shechter started thinking about her next project, it felt right.

“That was partly because the conversation about not having children had exploded. It had been so underground and thanks to social media it had really grown exponentially online. People were talking about it a lot. Often anonymously, but they were talking about it.”

When she began filming in 2016, Shechter knew very little about pronatalism. To her it meant family benefits offered by government, or a relative asking someone when they're going to have children. The deeper she dug, the more she realised it was a complex social system which she could “introduce people to as a framework to use to understand certain things that may not make sense. It works at your holiday table, and it works in pop culture messaging and how we sell products, and it works on a national level, from things like subsidies when you have children, to nationalistic genocidal efforts. Once you see it, you can't unsee it.”

Pronatalism is not just about promoting birth, but also controlling it. It was a driver of the slave trade, when black babies were property to be sold, and fuelled the American eugenics movement formed during the late 19th Century. In 1905, when President Theodore Roosevelt warned of a white “race suicide” (today's equivalent phrase is “white genocide”), forced sterilisation was one solution.

“Our current declining birth rate conversation to me, just goes right back to Roosevelt saying white ladies aren't having enough babies, and we don't want any immigrants,” Shechter says. “A lot of the fertility rate panic is coming from that, and whatever economic arguments people offer up are questionable.”

The documentary reveals that the eugenics programme was an inspiration for Hitler, and Shechter informs me that she estimates that two thirds to three quarters of her family were murdered by the Nazis within Hungarian Transylvania, while those in Romanian Transylvania like her mother, who had moved to Bucharest, lived. “Although they were building crematoria outside Bucharest,” she says.

Survivors often saw having children as a victory over Hitler. Did Shechter experience any communal pressure?

“I think so. I grew up with this idea that we have lost so many and we needed to make up for that and have more Jewish children and rebuild the Jewish world. I understand that completely. And,” she pauses for a moment,“I didn't do that, basically. And I wasn't going to. My husband got similar pressure.”

She grew up in a Jewish neighbourhood in Toronto where there were many survivors, attended a very Jewish high school, and remains connected to the city's Jewish community. Another reason why she did not talk about being childfree for so long, she says, is she knew it would be “a really unpleasant conversation”.

“The worst occasions were baby showers. Those were really strange experiences. People were talking about nothing but having babies and handing me babies. Eventually I started saying I actually don't want children and that completely alienated me from the group. Suddenly I was this sort of alien person. I'm sure, though, that there were other people who felt like me and they didn't feel empowered to really talk about it.”

My So-Called Selfish Life is out, proud and banging the drum for reproductive justice, bodily autonomy, diversity, and the joys, and challenges, of a childfree life. There are battles still to be won, rights to be fought for and protected, but more and more women are sharing their stories, and feeling empowered as a consequence. Education is key and, through her work, Shechter wants to “give people the tools to understand some of what is going on in the world, and then they can decide how they feel about it.”

“Social change starts with changing people's attitudes,” she says, “but then has to be followed by the activism that's needed to change policies that affect everyone.”

MY SO-CALLED SELFISH LIFE will be streamed worldwide from 6-16th May via www.showandtell.film