The fourth trimester, in plain language
What is actually happening in the first twelve weeks, and which of the hundred things you have been told are worth acting on.
The phrase gets used a lot and rarely explained. The fourth trimester is the first twelve weeks after birth, and the idea behind the name is simple: a human baby is born earlier in its development than almost any other mammal, because any later and the head would not fit. So the first three months outside are, functionally, a continuation of the last three months inside.
That one fact explains most of what a newborn does, and it takes the sting out of a lot of advice you are about to be given.
Why they only settle on you
A newborn has spent months in constant motion, constant sound and constant pressure on every side. A flat, still, silent cot is not a neutral environment to them. It is the opposite of everything they know.
This is why the baby who will not go down alone is not manipulating you and is not badly behaved. They are calibrated for a different setting. It passes, and it passes on its own schedule rather than on the one in the book.
What helps in the meantime is boring and physical: contact, movement, a firm hold rather than a light one, and noise rather than silence. What does not help is trying to fix it.
The cluster feeding evening
Somewhere between five and ten in the evening a lot of newborns feed almost continuously, unlatch, complain, and want to feed again. It looks exactly like a supply problem and it usually is not one.
It is worth knowing simply so that you do not spend that fortnight convinced something is wrong. If feeding hurts, if nappies are dry, or if the weight is not going the right way, that is a different conversation and it is one to have with a midwife or a health visitor rather than with the internet.
What is worth buying, and what is not
We sell baby things, so treat what follows with the scepticism it deserves. But the honest list of what earns its place in the first twelve weeks is short.
Something to swaddle with, if your baby likes being swaddled, and a good number of them do not. Bodysuits that open at the neck wide enough to come off downwards, because the day will come when you need that. More muslin than you think is reasonable. One thing that is soft and washable and always within reach.
What does not earn its place: anything that needs an app, anything that promises to make a newborn sleep through, and most of the six-piece coming-home sets, which are sized for a baby who has already been born and is already a different size than you planned for.
The bit nobody puts on the list
The fourth trimester is also happening to the adults. Recovery from birth takes longer than the leaflet suggests, and the sleep deprivation is not a background inconvenience, it is the main event.
The practical version of that: accept the food people offer, keep the visits short, and treat the first six weeks as a period to get through rather than a period to enjoy. Enjoying it comes later, and it does come.
