I went to pregnancy yoga last night. It’s like normal yoga, only everyone there looks like a whale and no one tries to stand on their head. In fact, such is the variety of ailments among us at this later stage of pregnancy that two of the women spend half the time being advised to avoid the moves and just sit on a beanbag and breathe, which makes me wonder why they didn’t save #163;7 and stay at home to do their breathing in front of the television.

But it’s a nice room - they give us lots of pink cushions and time to moan about our bad backs and heartburn, and the teacher is lovely. A former classroom teacher of much younger students, she now works for herself running classes for pregnant women and mothers and babies, all with the word “yoga” or “nurture” in the title. She tells me she adores her job and misses nothing about school life, least of all the endless planning and marking. Occasionally, I find myself wondering if I might find a similar way out, but then I remember that she’s a genuinely caring, enthusiastic baby lover, while I’m a cynical teacher who finds talk about nappies extremely boring and can’t stop sniggering when health visitors use the word “nipple avoidance”.

But for two hours on a Wednesday night I’m happy to enter her world and attempt to be “at one with the bump” while I work on breathing exercises that will see me through childbirth on a wave of calm submission to the pain and no need at all to swear blindly at my husband - blaming him for everything from the Second World War onwards and offering my worldly goods to anyone who will bring me an epidural.

In fact, when she offers me a leaflet for a course entitled “Nurturing couples - how to work together for a natural birth”, I even manage to take it without rolling my eyes. Reading down, I find out that the workshop will “help you and your partner discover a range of birthing and birthing support positions that will assist and calm you during childbirth”. I don’t have the heart to tell her that my husband’s ideal birthing support position is in the pub handing out cigars, so I promise I’ll mention the course to him.

At the end of the session comes the relaxation bit. You get to lie on the floor under a blanket while the teacher dims the lights and reads out calming words over a soundtrack of chanting monks. It’s really quite nice and lots of the women virtually fall asleep but, because I’m a teacher, this is never going to be possible. I can be drifting off on a wave of calm, obediently allowing myself to feel “centred to the earth” when I remember that I still haven’t filled out the special educational needs group’s timetable asked for two weeks ago, which reminds me that I told Jack’s mum at parents’ evening I would send home a handwriting book and I still haven’t, which in turn reminds me that I confiscated Shannon’s glittery gel pen in handwriting last week, put it on my desk and promptly lost it and she’s been asking for it back since. I can feel all the calming goodness of the relaxation session washing away as I drive home to complete the special needs timetable and find new worksheets for tomorrow’s maths lessons as today’s were way too difficult for them.

The yoga teacher has suggested we draw up a written plan for the birth. Suggestions involving scented candles, beanbags and relaxation music are bandied about. Some of the women talk about teaching their partners different massage techniques to help them “ride the waves of pain”. I don’t think I’m going to bother with any of that. My birthing plan is going to include the phrase: “Drugs - just say yes” and an instruction that my husband is calmly and slowly to repeat the sentences: “You don’t have lesson observation tomorrow. You don’t have tests to mark. You don’t have any planning to do,” for the duration. If that doesn’t work, we can always fall back on the breathing.

Jo Brighouse teaches at a school for children aged 4-11 in the Midlands, England.