The sclerotic culture of dithering that afflicts the higher-ups at the BBC has been mercilessly exposed in W1A. It turns out that fear of failure was always a managerial thing at the corporation. How else did Dad’s Army have such a bumpy ride to birth? As told in We’re Doomed! The Dad’s Army Story, one of the most enduring sitcoms ever made was very nearly never made.

“He has been in poor health for some time, but was cracking jokes to the last,” read the statement from Warren Mitchell’s family following news of his death today, at the age of 89. That will come as no surprise for those who remember the actor primarily as Alf Garnett, first in Till Death Do Us Part (on the BBC, 1965-75), and later In Sickness and In Health (1985-1992).

There’s a baby boom in sitcom. This week two of last year’s best comedies return for second helpings, each with a child in tow. In Detectorists (BBC Two on Thursday) Andy is out in the field panning for gold with a small sweet addition. But first Catastrophe is back – and the title holds good. For Sharon and Rob (played by series creators Sharon Horgan and Rob Delaney) parenthood is just as much of a disaster zone as the unplanned pregnancy which threw them together in the first series. And the jokes still come at you like rapid machine-gun fire.

Turning autobiography into comedy gold is an alchemy that has often been tried. Among them Caitlin Moran’s Raised by Wolves, Kathy Burke’s superb Walking and Talking, and the mooted but, as yet uncommissioned story of Jeremy Clarkson’s childhood, provisionally titled For Whom the Bellend Trolls.

When Jim Hacker MP was unexpectedly promoted to the position of PM, the classic sitcom Yes, Minister required just a small tweak in title and it was pretty much business as usual, albeit with a grander sense of potential impact. When the shit hit the fan, there was alarm, followed by quiet restraint and arched eyebrows before predetermined Machiavellian plans were unveiled and the credits rolled over a comforting closure.

For somebody who never seems to be short of things to say, journalist and author Caitlin Moran doesn’t half like to repeat herself. Raised by Wolves is, for those of you keeping score at home, her third attempt to tell the story of growing up chubby, eccentric and poor in Wolverhampton. Like last year’s novel How to Build a Girl this one is nominally fictional, but the addition of younger sister Caroline (Caz) as co-writer introduces something new.

There’s a tricky balancing act involved when writing a sitcom. Too much "sit" and you’re in danger of losing the laughs, too much "com" and it becomes increasingly difficult to find the space to land a serious dramatic punch. Get one of these things wrong and, like a fat man facing a baby on a see-saw, it looks all wrong and is no fun for anyone.

The latest sitcom from the United States is very much in the American mould of smart dialogue, pacy timing and some astute human observation layered with a hint of schmaltz. It concerns two thirtysomethings, Annie and Jake, who have been together for six years. In the pilot episode last night, she was expecting him to pop the question while they were on a romantic holiday, while he has planned to go on bended knee when they return home.

Commissioning new sitcoms is a notoriously imprecise science. The first episode, and sometimes the first series, finds a sitcom at its least sure-footed. Keen to tell you all about itself, it tends to behave out of character, gabbling nervously and exaggerating every gesture. It might never find its feet, but you can rarely tell from one half-hour introduction. My own personal hostage to fortune was to have a sense of humour bypass when reviewing Father Ted. (But then episode one wasn't that funny.)

Joanna Scanlan and Vicki Pepperdine are two-thirds of the talented team (Jo Brand was the other) who brought us the excellent Getting On, now probably lost to UK screens after three series but which will appear in an American format next year. Now the duo have co-written and star in Puppy Love, about a dog trainer on The Wirral; but whereas Getting On - a quiet, gently paced and often moving comedy set in the NHS - delivered its humour with great subtlety, Puppy Love (directed by Susan Tully) is frantic and obvious.