Knocked Up (15)

Judd Apatow's smash-hit follow-up to The 40-Year-Old Virgin is one of the less spurious, more realistic romantic comedies of recent years: a woman gets pregnant on a one-night stand, so the prospective parents get to know each other before the baby is born. But, considering the refreshing absence of wacky mix-ups, Knocked Up still isn't quite credible. The father-to-be, Ben (Seth Rogen), divides his time between smoking weed and setting up a website which catalogues nude movie scenes. The mother-to-be, Alison (Katherine Heigl, who plays Izzie Stevens in Grey's Anatomy), works in production at a Hollywood gossip TV channel. When she's given the chance to appear on camera, she goes out to a club with her sister to celebrate, and a slovenly, doughy man buys her a beer. Several drinks later, Alison and Ben are back at her place.

Some reviewers have argued that there isn't enough alcohol in the world to make someone who looks like Katherine Heigl have sex with someone who looks like Seth Rogen, but we've only to think of Pete Doherty to know that stranger things have happened. I didn't have any trouble suspending my disbelief until the next morning. Lying naked in Alison's bed, Ben looks like a walrus in a clown wig, but Alison agrees to go out for breakfast with him.

Once he's vomited in the gents, he mocks her job, tells her about his "internet website", admits that he's a Canadian living illegally in the US, and brags about his drug intake. Alison makes her excuses and leaves. But eight weeks later, she realises why she keeps being sick in the mornings, and she decides, in quick succession, to keep the baby, to take Ben with her to the doctor, and to embark on a relationship with him. It's not impossible that she would make these decisions, but a few clues as to why she'd make them would have been nice. Knocked Up doesn't say that Alison is a pro-life religious conservative, nor that she's always wanted to be a mother. All we know is that she's an ambitious TV presenter in her early twenties, and that preg-nancy could be a disastrous career move.

So why is she joining genes with such an unsuitable boy? They certainly don't have much chemistry to go with the biology, and Apatow never persuades us that the pair wouldn't be better off apart, largely because he doesn't let them have any conversations which aren't about gynaecology. For most of Alison's scenes, she's talking to her neurotic big sister Debbie (Leslie Mann, aka Mrs Judd Apatow), while for most of Ben's, he's talking to his stoner buddies and to Debbie's sardonic husband (Paul Rudd).

It's these conversations which are the movie's raison d'etre. Like The 40-Year-Old Virgin, which co-starred Rogen and Rudd, Knocked Up is a loose, semi-improvised patchwork of pop-culture riffs and foul-mouthed mickey-taking. Apatow lets the camera roll while his actors crack jokes at each other, whether they're related to the plot or not. As a result, the film is 10 minutes longer than Citizen Kane, which should be against the law for a romantic comedy. But for much of that time it's a bundle of joy: a big-hearted, freq-uently hilarious charmer which is more open about sex and drugs than most so-called gross-out movies. I just wish I could be more optimistic about Alison and Ben. They've got tough times ahead, but maybe that's a matter for Knocked Up 2: Bringing Up Baby.