Catherine Deneuve is a French national treasure, and it’s always good to encounter her onscreen, even in an overly mawkish melodrama like Martin Provost’s “The Midwife.” She’s excellent as a dying woman who seeks out her estranged stepdaughter to make amends, encouraging the younger woman to let loose in the process. The shopworn premise, however, puts the film on life support from the very start, and even its excellent cast can’t completely elevate the material beyond its essential banality.

Deneuve’s Beatrice Sobo (shortened, we are eventually told., from Sobolevski) is, in any event, really the supporting character in Provost’s script; the titular protagonist is Claire Breton (Catherine Frot), who’s worked for years in a small Parisian clinic, literally handling the most difficult cases. (One of the picture’s most effectively authentic elements, in fact, are the birthing sequences, which highlight the artificiality of such scenes in other films.) But the clinic is about to be closed—it needs to be refurbished, and the cost is prohibitive—and the operation is being transferred to a huge modern hospital, where it will be handled in sterile, assembly-line fashion. Claire simply cannot bring herself to become part of the move.

She also has a problem with the handsome son Simon (Quentin Dolmaire) whom she raised on her own. He’s a med student who hopes to become a surgeon, but he comes home one weekend with a girlfriend he’s very serious about—so serious that she’s three months’ pregnant. And this just at the time when he’s about to take exams he must pass to continue his studies.

As unsettled as these circumstances make Claire’s life, however, her greatest consternation comes from the reappearance of Beatrice (Deneuve), the mistress whose sudden departure years before caused her father, a champion swimmer, to commit suicide. Beatrice is one of those free spirits who has always lived by her wits—gambling is a specialty. But now she’s terminally ill with brain cancer, and wants to reconnect. Of course, she doesn’t know that her once-upon-a-time lover killed himself when she left him, but after getting over the shock, she tries to resolve things with Claire, who’s understandably bitter and standoffish, though she ultimately decides that it’s her duty to help the woman.

Thus begins a halting rapprochement between the two, something Beatrice needs not only because she’s terrified of her prognosis, but because she’s close to broke and in need of a place to crash. Beatrice’s impact on the uptight midwife is, of course, immense. Claire loosens up, even starting to drink alcohol and eat meat. She remains something of a scold, but her prim attitude gradually breaks down as she and Beatrice grow closer.

After a halting start Claire also develops a relationship with Paul Baron (Olivier Gourmet), the son of her aged neighbor at her rustic cottage. They initially bond over the riverside garden they share, and she gradually warms to the long-haul trucker’s gently nomadic vibe. Needless to say, Beatrice encourages the romance.

Frot, a formidable actress who herself let loose in “Marguerite,” is suitably buttoned-up as Claire, always wearing a raincoat only a bit newer than Columbo’s that Deneuve’s Beatrice periodically insists she discard for style’s sake. Her subtlety allows the other Catherine free rein, and Deneuve seizes the opportunity. It’s not one of her best performances, but she brings enormous vitality to the dying woman that might not be realistic but is certainly fun to watch, since Beatrice is aggressively opinionated, needy, self-confident and, as it turns out, determined to end her life on her own terms. Both Gourmet and Dolmaire provide nice support, and Mylene Demongeot, another celebrated French actress of a certain age, makes the most of a cameo as one of Beatrice’s cohorts, but it’s the contrast between Frot and Deneuve that gives “The Midwife” what heft it possesses.

There’s nothing special in Thierry Francois’ production design or Yves Cape’s cinematography, which prefer grittiness to an attempt to glamorize the material in a Ross Hunter “women’s picture” way. Nor does Provost do much from a directorial perspective beyond standing aside and giving his cast, especially the leading ladies, plenty of freedom to make the dialogue he’s provided them with sound better than it is. Provost’s earlier film, “Seraphine,” showed that he has more talent and sensitivity than this follow-up demonstrates.

Still, though a relatively slight tale of a woman who breaks free of a stifling life as a result of an unexpected encounter with her past, “The Midwife” offers the opportunity to watch two fine actresses joust, and for some that may be enough.