Newborn startle reflex usually disappears around 3 to 5 months of infancy.
Neonatal startle reflex is one of the primitive reflexes of the newborn period, which is a normal physiological phenomenon and does not need to be overly worried, nor does it need special treatment. Generally, 3 to 5 months after birth, due to the gradual development of the brain and nervous system, the startle response will gradually weaken or even disappear.
The startle reflex is mainly caused by the immature development of the cerebral cortex, imperfect development of the nervous system, and high excitability of the central nerve cells, so newborns may become tense when they are stimulated by external sounds, touch, etc., which will cause the startle reflex.
If the infant still exists after more than 6 months, it is considered that there may be pathological reasons, and it is recommended to go to the hospital in time for a detailed examination to make a clear diagnosis, and carry out targeted treatment in time, so as to avoid delaying the treatment time.