The Dardenne brothers, Luc and Jean-Pierre, have long functioned as a Belgian answer to Ken Loach, pitching their film-making camp among the most marginalised and forgotten. Normally this means clear-eyed fables of teenagers and twentysomethings living in difficult circumstances: nightmare parents, petty crime, drugs and jail. In a series of films between the mid-90s and early-10s, they twice won the Palme d’Or, plus the best screenplay and the Grand Prix at the Cannes film festival for their distinctive brand of naturalist storytelling, employing a light-on-its-feet handheld travelling-camera style to deal with some seriously dark material. Then came bit of a wobble; perhaps their success opened up opportunities they couldn’t turn down. They found themselves working with an actual film star (Marion Cotillard) and then turned to hot-button issues – radical Islamism in Young Ahmed, illegal immigration in Tori and Lokita – which perhaps didn’t bring the best out of them.

Well, all this is a preamble to saying that Young Mothers sees the Dardennes fully back in their comfort zone, with material and actors they know how to deal with. The subject, as the title suggests, is the young women who find themselves pregnant, or with very young children, and who are heartbreakingly ill-equipped to deal with the situation. Challenges range from basic techniques of baby care – one, for example, has to be reminded to take her phone off the baby changing mat – to the emotional storms of recalcitrant boyfriends, drug dependency and narcissistic and uninterested parents of their own.

You could imagine the world’s most earnest (and hard to watch) documentary being carved out of this. But what the Dardennes have is an almost miraculous ability to make even the most rotten scenarios – a hapless adopted teenager stalking their birth mother to her crummy job, or an addict waking up in hospital after an overdose – live and breathe through the sheer power of empathy.

It helps of course that the Dardennes are absolute masters at directing young actors, male and female; no one here puts a foot wrong or is anything other than fully identified with the role they play. The brothers juggle several strands effortlessly, and construct their narratives so precisely that even the existence of a bedroom window overlooking the Meuse river seems like a major moment of triumph.

Part of what makes the Dardennes’ films work so well is the way they use the camera; almost entirely handheld, it is like an extra person in the room, or car, or on the street – and by extension it brings us, the viewers, directly into the scene. It’s a major point of contrast with Loach, who prefers a more classical, coverage-oriented style, where the camera (and us) sit back and watch what’s going on almost invisibly. Moreover, while the Dardennes don’t use anything as crass as point of view shots, their filming while walking and nervy pans get inside the anxious heads of their protagonists with tremendous effectiveness. Long may it continue.