Not a great name, as it can persist for up to 6 months!

Large muscle groups, usually limbs but can be face. Can wax and wane with child remaining sleep. Usually bursts lasting seconds, up to a few minutes.

During sleep only, and stops when wakes.

Other normal baby movements include neonatal release phenomena, including tremors (equal amplitude around fixed axis), jitters (recurrent tremor).

Reassuring if baby unbothered by it; baby in first 7 days of life; if it can be suppressed by passive flexion.

Differential would be hypoglycaemia, hypokalaemia; drug withdrawal; HIE or intracranial lesion; myoclonic epilepsy, startle (including hyperekplexia), hyperthyroidism.