Older viewers may feel, well, erm, old, to see that this film comes prefaced with a wise statement – handed down as if ’twere written on tablets of stone – from the 2009 film Jennifer’s Body. (Wasn’t 2009 about four years ago?) Portentously proclaiming “Hell is a teenage girl”, it’s an apt little quote to kick off this neatly done teen movie, which unusually throws a rare biological condition into the typical mix of virginity loss, relationship drama and high school politics. Our lead Lindy (Maddie Ziegler) discovers, after a routine medical appointment, that she does not have a uterus or vaginal canal deeper than “a vaginal dimple”, making the prospect of first-time sex with her dreamy boyfriend Adam (D’Pharaoh Woon-A-Tai) more than usually anxiety-making.

For the majority of its runtime, Fitting In takes a commendably character-based approach to something that could have become a preachy issues film. Lindy is a person, not an avatar for anyone and everyone with her condition. There are contemporary socio-political resonances, of course; how would Lindy be classified by people who define a woman as someone with a vagina and uterus? But writer-director Molly McGlynn (who was born with the same condition) hasn’t written a one-dimensional transphobic character to help make this point. Likewise, Lindy does experience an attraction to an intersex person, Jax (Ki Griffin), who she’s then embarrassed to be seen making out with at a party; but again, while this is an illustration of how internalised attitudes of shame can poison people against those with whom they ought to have common ground, McGlynn shows this rather than telling us.

Most of the film looks and feels like the kind of inexpensive teen movie there used to be every couple of weeks during the 90s. It’s not up there with the heights of the genre – Clueless, The Craft and Ginger Snaps (name-checked in the film) can rest easy – but represents a thematically rich addition to the canon.

• Fitting In is on UK digital platforms from 9 September.