Foetal development

Trimester	Weeks	Structures	Sensory	Motor
First	01/12/16	Placenta 3/52 Heart 4/52 Brain 4/52 Spinal cord 4/52 Olfactory nerve 7/52 Semicircular canals 8/52 Limbs and digits 8/52 Major organs 8/52 Sex organs 8/52 Olfactory bulb 8-9/52 Cochlear 10/52	Taste and smell (olfactory) Hearing (cochlear) Sight (rods and cones) Sensation: touch pain temperature proprioception	Neurological and musculoskeletal coordination (closed fist)
Second	13-28	Muscle and bone Skin Taste buds Eyebrows and lashes Finger/toe nails Hair on head Lanugo (fine hair covering body) Vernix (waxy protective skin covering)	Hearing	Swallowing ‘Fluttering’/’quickening’ Sucking reflex Startle reflex
Third	29-40	Rapid weight gain Loss of lanugo (fine hair) Thickening vernix Bones fully formed	Stress: Increased cortisol and adrenaline of the mother pre sets baby at a higher level. – anxious – clingy – colicky	Forecful kicks Regular breathing movements