The French title of this film is L’Événement: another serviceable English translation might have been “The Event”. But in the original language, it’s also a loaded linguistic near-miss with L’Avènement: “The Advent”, or more baldly, “The Birth”.

The prospect of the first of these things leading to the second has Anne (Anamaria Vartolomei) in a daze of dread. A promising student living in Angoulême in the early 1960s, Anne is aware that education is her best hope of transcending her working-class roots.

But months before her exams, she has fallen pregnant after a one-time-only liaison with a student from another town, and recognises that carrying the baby to term would send her academic future up in smoke.

How best, then, to quell the blaze before it catches? Abortion is the obvious solution. But it’s also illegal, punishable by imprisonment, and entailing significant medical risk. Happening, which screened at the Glasgow Film Festival this week in advance of its UK release next month, follows Anne’s clandestine search for a procedure she can barely dare mention to her peers – and which everyone around her is dogmatically determined to rule out on her behalf.

Deftly adapted by director Audrey Diwan from a novella, Happening is a period piece, but it’s acted and shot with a shivery immediacy. Diwan’s camera trains itself on Anne at almost all times, and Vartolomei’s wonderfully subtle and controlled performance allows you to feel every twist and jerk of her mounting internal panic.

The friends she takes in to her confidence back off, and she’s variously rebuffed and misled by the male doctors she approaches for help. As for the father, he’s more concerned that Anne’s anxiety will make a bad impression on his friends from home.

The message Anne receives from all directions is as despair-inducing as it is simple: unwanted pregnancy is a matter for women alone. No wonder Anne’s female friends are horrified at the thought of sexual activity: they know the dangers.

Is it a challenging watch? Unquestionably – though only a second or two could be fairly described as graphic, and the termination scene itself, which unfolds in a breath-stopping single take, says everything while showing almost nothing.

Rather, it’s Anne’s growing sense of abandonment that makes your heart race, so by the time she finds her way to an alleyway with 400 francs in an envelope, you’ve long been aware of what’s at stake. Diwan builds towards this sequence as if working towards the denouement of a wartime resistance thriller – the point at which the culprit is revealed. In this scenario, however, the film is on the culprit’s side.

15 cert, 99 min. In cinemas from April 22