One of the unintended consequences of pregnancy, at least for me, was the scope for learning. All sorts of things have popped up, some quite out-of-the-blue, others were ‘should have worked that out’ sorts. Some of the latter relate to changes in digestion.

One of the things we all expect, based on the pregnancy stereotype, is ‘hormones’. This is really only singular for the purposes of this description, and its name is progesterone. There is a normal up and down of progesterone during the menstrual cycle, where for two weeks or so, it is about the same level as a man’s, but for the rest of the time, it is considerably higher, and peaks at a level around 20 times the lowest level. During pregnancy, progesterone carries on increasing in concentration, and can reach a quarter of a million times more than that of a man. It normally peaks in pregnancy between 20 and 100 times higher than at any other time in a woman’s life.

Small wonder then, that it has an effect on her behaviour. It also has other effects. It slows the muscle contraction in the gut, meaning that the food that is eaten is digested over a longer period of time. This probably has the added advantage that the nutritional value in it is absorbed a bit more fully, but it also means that the micro-organisms in the gut, the E. coli and so on, have longer to do their stuff. This means that they produce more waste products, including more gaseous waste products.

The non-scientific observation is that ‘she is eating for two, and so everything else doubles up as well’. Quite why, is not explained. My observation that she now perfumes the room as often as I do, has, however, been contested. By she.

This has led to how such a proposition might be tested and thus, a conclusion drawn. Clearly the frequency needs to be recorded, and the length, and the nasal response. The Fart Chart must have these categories, at least.

What is less clear is the locus. Do those on the train, or when one of us is alone in the flat, count? What about the silent, anosmic ones? If unheard and unsmelled, they may escape detection altogether. What about when we play a duet, and thus turn the bed or the settee into the brass section of the London Symphony Orchestra? Must we eat the same quantity of egg and artichoke, to ensure fair play?

We have yet to make a decision. It is too difficult. The biggest problem for me is, how I will be able to justify the current level of release after the due date.

I don’t know whom to credit for the following cartoon, but it is clear that I am not the first to observe this phenomenon: