Why did my newborn's body shake for a second?

Eight words, sent immediately

If baby body shakes a bit it's ok. No punctuation, no detail, no context. That's what it looks like when you've just watched something and your brain has stopped working.

It was sitting in a conversation that also contained a water filter problem and how long milk takes to cool in a Kikka Boo warmer, which is a fair picture of that month.

Shakes covers several different things

The startle reflex, also called the Moro reflex, is where her arms fling out and then come back in, often after a noise or when you put her down. It looks dramatic, is very common, and fades over the first few months.

Jitteriness — a fine trembling of the chin or the hands, usually when she's crying, cold, or being undressed.

And little jerks of an arm or leg during active sleep, which happen constantly.

They can look similar, but there are a few useful differences to watch for.

The thing that tells them apart

Hold the limb that's shaking, gently. Ordinary jitteriness stops when you hold it. Movement that carries on regardless is the kind to report.

The other question is whether she's there with you. A jittery baby is awake and responsive, and settles when she's comforted, fed or warmed up. Movement that comes with a blank, unresponsive stare is a different report entirely.

What we'd note if it happened again

Which part of her, and whether it was one side or both. How long. Rhythmic and repetitive, or irregular. What she was doing — awake, asleep, feeding, cold, being moved. Her breathing and her colour during it. Her eyes. And whether touching her stopped it.

And film it, if you possibly can. A ten-second video means a doctor is looking at what actually happened rather than at your description of it at two in the morning.