Offspring wraps its seventh season, but do viewers actually want more?

What's the right time to end a series? When it's delivered several strong seasons, built a devoted following and can bow out leaving viewers clamouring for more? (Think of SeaChange or Seinfeld). Or when the ideas start to sag, the cast looks as if they're operating on autopilot, every possible secret relative has been dragged from the woodwork, and every potential story angle seems to have been exploited? (Think of The Secret Life of Us or The Affair).

It's a relatively good problem for a producer or a TV network to have, preferable to coping with a dud, but it's still a problem. And given that the TV business is relentlessly competitive, that it's so hard to establish a show and build a loyal audience, no one would want to let go of a prized production prematurely. Still, staying too long has its traps: instead of going out on a high, the show limps away leaving a sour after-taste, the previous glories over-shadowed by the subsequent deterioration.

Do viewers want more?: 'Offspring'has just wrapped its seventh season.Credit: Network Ten

That dilemma confronted the creative talents involved in Offspring, which has just wrapped its seventh season. Built around the life of obstetrician Nina Proudman (Asher Keddie), the series combined romantic comedy with domestic trials, incorporating the joys and tragedies of a maternity ward. Five seasons of the Melbourne-based production screened before it ended under a cloud of uncertainty in 2014. After a two-year absence, it returned last year for two more seasons.

As well as Nina's dilemmas, Offspring deployed a large and likable core cast to offer a rollercoaster ride through the pleasure and pain of modern romance and parenthood. At its warm heart was the celebration of a messy, loving community revolving around the Proudman family.

'Offspring' has deployed a large and likable core cast.Credit: Network Ten

It was an inviting environment. The characters glowed; their clothes were well-curated and accessorised statements of personality; their homes inspired real-estate envy; an abundance of attractive places to eat and drink existed in close proximity. The Proudmans' world looked like a bit of an urban dreamscape.

Before the break, there was an almost-passionate public engagement with the show. Viewers invested in the love affair between Nina and Patrick (Matthew Le Nevez), and the outpouring of grief when he died just before she gave birth to their baby daughter at the end of the fourth season was powerful. How she would go on was the pressing question that powered the fifth, with Keddie delivering a superbly nuanced portrait of fragility and resilience, ably supported by Kat Stewart as Nina's firecracker sister, Billie. Many of their scenes together were magnificent.

In the early days, Nina was the spine of a series built around her work and love life. But as it went on, the relationship between the sisters became the foundation, Nina's anxious uncertainty contrasting with the impulsive Billie's (frequently wrong-headed) assurance and combustible energy.

Yet the post-hiatus seasons haven't achieved the spark or momentum that distinguished the earlier ones. Yes, there was some snappy dialogue and an engaging sense of community. But the show seemed to struggle with what to do next and created the impression that, rather than adhering to a solid underlying philosophy, it almost stumbled into its stronger scenes. There was too much padding, detours that didn't lead anywhere especially interesting.

The most recent season featured the relationship between Nina Proudman (Asher Keddie) and Harry (Alexander England).Credit: Network Ten

The most recent season featured the relationship between Nina and Harry (Alexander England), and the doctor and the crisis-manager proved a good match as she was so often in crisis mode. Which has been, well, fine, if not exactly electrifying. Offspring has always been at its least satisfying when Nina ricocheted around in a state of frazzled anxiety, responding to ringing phones and wringing her hands. It has shone when its idiosyncratic characters have been allowed more space to breathe.

Yet there's been a nagging feeling that the writers didn't know how to keep some members of the ensemble productively occupied, notably matriarch Geraldine (Linda Cropper), but also Will (T.J. Power) and poor Elvis (Lawrence Leung), who's long been reduced to an eccentric ornament.

Although Geraldine was eventually granted a couple of moments of authentic emotion, revealing a fear of growing older and being alone, for much of the season – which began with her self-proclaimed "Geraldine Day" – she seemed insensitive and childish in her self-absorption.

Meanwhile Will, who appeared in season six as a previously unknown Proudman sibling, endeavoured to be more spontaneous, sought advice from Jimmy (Richard Davies), walked backwards down streets, and tried to recover from rejection by Kerry (Ash Ricardo). He eventually married her, though their union always seemed more a convenient construction than a case of irresistible attraction.

Ten, now facing takeover by CBS Studios, has yet to announce a decision about the future of Offspring. But if this is the end, what's likely to be remembered are the heights attained in its middle period, rather than the seasons that followed.