The Weekend's Viewing: Call the Midwife, Sun, BBC1 Sherlock, Sun, BBC1

I do understand why creators don't much care for critics.

You've conceived a project, borne it for months, along with the attendant nausea and blood pressure problems. And then, after the painful labour necessary to actually squeeze it out into the world... as you lie there exhausted, raw and spent... some bugger comes along, leans into the crib, and declares that your baby is ugly. Or, well, just a little homely, perhaps, as is the case with Call the Midwife, BBC1's new Sunday evening drama. It's been born with a silver spoon in its mouth, this: written by Heidi Thomas, based on a best-selling memoir by Jennifer Worth and starring Jenny Agutter, Judy Parfitt and Pam Ferris among others. But from the moment you hear the patrician creak of Vanessa Redgrave on the voiceover, you sense there might be trouble ahead. "Midwifery is the very stuff of life," she says plangently, "Every child is conceived in love or lust and born in pain followed by joy or by tragedy and anguish. Every birth is attended by a midwife. She is in the thick of it. She sees it all."

In this case, the midwife is Jenny, who arrives at the Sisters of St Raymond Nonnatus in the East End in 1957 to be tutored in the rich tapestry of life, from batty nuns with an addiction to cake, to a cheery couple with 24 children and another on the way. "I must have been mad," she says arriving on the doorstep, "I could have been an air hostess." But here she is instead to receive her education in human variety and the simple goodness of Sister Julienne, one of those sagacious Mother Superior types whose job it is to nudge sheltered young gels towards greater wisdom. And the first thing that will probably strike you about the East End in 1957 is how spotlessly clean it all was. Yes, there are women brawling in the streets in a picturesque manner (one would expect nothing less), but there isn't a bit of litter anywhere, let alone anything more noisome, and it seems that barely anyone at all smoked back then.

Pearl does, but I think that's because Pearl is the drama's token slattern. Everyone else Jenny has met so far is a salt-of-the-earth type designed to confound her middle-class prejudices, but Pearl is a much tougher case. "I've got some shocking discharge!" she says winningly, hoicking up her skirt for an examination. Jenny is visibly appalled, but after Sister Julienne steps in ("I'm afraid the lump in her vulva appears to be a syphilitic chancre"), Jenny comes to realise that there's no place here for judgemental prudishness. What Pearl needs, besides penicillin, is a good dose of love – a medicine that also proves miraculously efficacious when Conchita's 25th child is born prematurely in the middle of a London pea-souper, and which I suspect will turn out to be applicable in a lot of Jenny's future cases. As Vanessa Redgrave says when she comes back again: "Love was like midwifery... the very stuff of life, and I was learning how to fly with it through all the streets, like the river to the sea." If you feel you can withstand that kind of thing, then Miranda Hart pitches up next week to add a comic toff to the roster.

Let's be honest, the last two episodes of Sherlock have had an almost impossible task living up to Stephen Moffat's opener. But last night's episode, "The Reichenbach Fall", was pretty good even so, with Andrew Scott's Moriarty (a shade too much Graham Norton for my taste) forcing our hero into a lethal tango of plot and counter-plot. I won't say too much about the ending, except to note that Moffat and his colleagues have written themselves into a hell of a hole with regards to the next series. If they don't explain, there may be riots.