Watching the trailer for Juno you could be forgiven for thinking its eponymous heroine, a 16-year-old schoolgirl who accidentally gets pregnant by her best friend, wisecracks all the way into the delivery room. Although Juno, played by Oscar nominee Ellen Page is sassy, undeniably glib but precociously insightful, this brief clip of her hip apathy being momentarily unsettled by impending motherhood, unsurprisingly, only tells part of the story. If her quips are seen as the appropriate bait to entice UK audiences into the film, by contrast, the substantially longer US trailer seems keener to establish Juno’s various relationships and the consequences of her situation, the troubled teenager confiding in her father that she is “dealing with things way beyond my maturity level”.

If you’ve seen Page’s belly on the film’s poster – and you really can’t miss it – I’m not spoiling anything by revealing that she doesn’t have an abortion. Despite visiting a rather unwholesome looking clinic and being told by a classmate protesting outside that her foetus has already developed fingernails, no explanation is offered as to why she plans to continue with the birth and present the baby to a childless, affluent young couple. This has led to Juno, four times Oscar-nominated and currently the most financially successful independent film ever, securing comparisons to last year’s acclaimed indie comedy-drama Waitress, in which Keri Russell’s diner employee also proceeds with her pregnancy, despite the birth threatening to keep her trapped in a loveless marriage; and writer-director Judd Apatow’s £75million grossing blockbuster Knocked Up, in which a career-minded television presenter conceives during a one-night stand with a slobbish manchild.

Juno’s 29-year-old screenwriter Diablo Cody has shrugged off the emergence of an accidental pregnancy comedy sub-genre as simply “foetus madness”. In America though, which recently recorded its lowest rate of abortions in three decades, yet which retains the highest teenage pregnancy figures in the world, the film’s release has prompted a flurry of newspaper articles, blogs and counter-blogs, fostering the unedifying spectacle of fictional foetuses being kicked around as political footballs for pro-life, gender and abstinence agendas.

Abortion, in terms of establishing a story arc for comedy, is pretty much a narrative non-starter, so any claims that these films endorse pro-life sentiments appear spurious. True, in Waitress, Russell’s character interrupts her doctor before he says the ‘a’ word, while in Knocked Up, the crude euphemism “shmashmortion” is all that’s uttered. This might be interpreted as a refusal to engage with the issue but asking the director of The 40-Year-Old Virgin to educate you on abortion is as misguided as watching Vera Drake for laughs. Both Mike Leigh’s 2004 masterpiece, starring Imelda Staunton as a back alley abortionist in 1950’s London and more recently, the harrowing Ceausescuean-era Romanian Palme d’Or winner, 4 Months, 3 Weeks & 2 Days, present a non-judgemental perspective on abortion in abject contrast to the chillingly prohibitive environment of their setting, restrictions of freedom that the vast majority of us can fortunately only imagine.

The UK currently has the highest teenage pregnancy rates in Western Europe, but we don’t share the US’ intensity of abortion debate. Perhaps this is one reason why Juno’s pregnancy functions more as a punchline in the trailers on our screens, instead of the swiftly established context for consequences it serves for in the American version.

If Waitress, Knocked Up and Juno reflect the times in which we live and procreate, they reaffirm that unplanned pregnancy is not the disaster it was in Vera Drake’s era and although Juno may call herself the school’s “cautionary whale”, her experience is not the taboo it once was. Movies in bygone decades tended to treat accidental pregnancy as tragedy, in hand-wringing dramas of recrimination such as Not Wanted (1949) and Blue Denim (1959), while right up to the likes of Cabaret (1972), The Godfather: Part II (1974) and even in a teenage rites of passage like Fast Times At Ridgemont High (1982), abortion was only invoked straightforwardly and seriously. If a comedy focused on accidental conception, it was invariably in formulaic pap like the Hugh Grant vehicle Nine Months (1995).

These films are escapist, as some of the best comedies are, but you know the babies are happy and spread happiness in Waitress and Knocked Up. Their situations are obviously unconventional, but they reflect the modern reality of many children raised outside the traditional nuclear unit. In Waitress, motherhood emboldens the central character with the self-conviction necessary to abandon a dead marriage and strike out as a single parent. In Knocked Up, the mismatched couple are unfashionably brought together by their child and can rely on a sister and circle of hapless but caring friends for support. Baby Mama, released in May, looks set to continue this trend. Starring Tina Fey from Channel 5’s 30 Rock as a career-minded businesswoman who wants to have a baby before her biological clock stops ticking, she learns that she has little chance of conceiving and hires a surrogate. When the surrogate turns up on her doorstep, desperately needing a place to stay, the odd couple are compelled to prepare for the birth together.

None of these women conclude their stories as victims. They cope with the burden of responsibility and the outrageous quirks of fate and indie filmmaking. But it’s the smart-talking Juno’s resolve to ignore others’ counsel and to remain the principal agent of her baby’s, and perhaps more importantly, her own destiny, that places her ahead of the cinematic curve. Juno reinforces the notion that every birth is different and dares to suggest that a teenage single mother might actually know what’s best for her child.

A version of this article originally appeared in the Scotsman, February 7, 2008.