Non ho trovato una traduzione esatta in italiano e quindi penso che il termine debba essere descritto con una parentesi con il termine inglese.

Si tratta di movimenti fetali che indicano comportamenti di stress.

Estensione faticosa del tronco seguita da tentativi di flessione del tronco - stiramento/soffocamento

Fetal Movement Research

Stress behaviours

Stretch/drown “Labored” trunk extension followed by trunk flexion attempts.

https://books.google.co.uk/books?id=ByL4yvs0mtYC&pg=PA212&lp...

Stretch/Drown: This is a configuration of labored trunkal extension, often also accompanied by arm extension and at times leg extension, which is then followed by an apparent effort to move the trunk back into flexion. This pattern of stretching and tucking may be repeated several times. At times the stretching component is quite prolonged. It frequently follows a pattern of decreasing respiratory rate at times ending in a respiratory pause. Often in the course of this motor pattern, inspiration or expiration has halted, leading to increasing color change to dusky. The pattern gives the impression of the struggling action of drowning, while attempting to regain breathing. It is also referred to as “motor drown.” Attention needs to be paid to the successful
reactivation of respiration. In successful efforts after a burst of drowning-like behavior, respiration restarts, albeit now often tachypneically. In other cases the drowning may be followed by limpness and a prolonged respiratory pause,
requiring containment into trunkal and extremity flexion, at times, additional stimulation in order to reactivate breathing.

https://nidcap.org/wp-content/uploads/2013/12/B.-Manual-Natu...