Your baby goes through many changes over the course of your pregnancy. Here is a general look at the phases of your baby's growth and changes during your pregnancy.
View each week period below learn how your baby will progress.
Under 26 Weeks
Unable to maintain temperature without heat source.
30-60 breaths per minute if able.
Will require respiratory support to maintain respirations.
Heart rate 120-160 beats per minute depending on activity.
Mostly twitchy, jerky movements and startles easily. Does not offer much resistance when handled and has low muscle tone. Arms and legs extended outwards.
If you attempt to alert a baby at this stage it will disorganize all body systems Eyes may be still sealed shut. Unable to tighten lids well to protect against the light. Does not focus on anything and eyes may be disorganized and float a bit.
All major structures to hear are basically in place by 25 weeks. May become disorganized to sounds around to the sounds around them.
Skin is very fragile and sensitive. Touch can cause the baby to become disorganized.
Shows low tolerance for social interaction.
26 to 28 Weeks
Unable to maintain temperature without heat source.
30-60 breaths per minute if able.
Will require respiratory support to maintain respirations.
Heart rate 120-160 beats per minute depending on activity.
Mostly twitchy, jerky movements and startles easily.
Low muscle tone.
Arms and legs extended most of time but do get pulled in sometimes briefly.
May seem briefly "alert" at times.
Has limited ability to tighten eyelids to protect from light.
Eyes open occasionally but do not focus much.
Poorly controlled eye movements.
Still may become disorganized by visual stimulation.
At about 28 weeks infant may begin to tolerate soft sounds.
Still may become disorganized to sounds.
Skin still fragile and sensitive.
Still may become disorganized to touch
28 to 30 Weeks
30-60 breaths per minute may require mechanical ventilation.
Heart rate 120-160 May have periodic breathing or apnea (forget to breathe).
Movement predominantly jerky though with support can sometimes be smooth with support.
Legs move around a lot more.
Still tends to keep legs extended most of time.
Still becomes disorganized when lifted or held.
Ability to tighten eyelids to protect from the light becomes improved at about 30 weeks.
Opens eyes more often.
Starts to express certain behaviors to soft sounds.
Can still become disorganized to loud sounds.
Remains very sensitive to touch and still becomes easily disorganized.
Still not very social although now may start to quiet and alert to parents voice.
30 to 33 Weeks
30-60 breaths per minute may require mechanical ventilation.
Heart rate 120-160.
May have periodic breathing or apnea (forget to breathe).
Legs now begin to flex some during sleep.
Bends and moves arms and legs frequently.
Movements becoming more controlled.
Still have tremors and startles.
Now starts to rouse some before feeds.
Starts to have some alert times at about 32 weeks.
Starts having good wakeful/sleep periods.
Is having continued improvement with lid tightening for light protection.
Focuses briefly like upon faces.
Opens eyes more frequently when lights are low.
Show preference to hearing human voices.
Response to sound becoming more organized still may become disorganized.
Skin is delicate and a bit fragile yet.
Tolerates touch better though becomes disorganized with repeated touching (i.e. stroking).
Responses to pain very from infant to infant and extended handling may cause disorganization.
Improving social interaction.
Alertness and eye contact develops at about 32 weeks.
33 to 36 Weeks
It is during the later part of this time frame that a baby may be able to maintain his/her own temperature.
30-60 breaths per minute may require mechanical ventilation.
Heart rate 120-160.
May have periodic breathing or apnea (forget to breathe).
During sleep infant is becoming more flexed. Infant kicks vigorously when awake.
Movement becoming more smooth and controlled. Head may turn from midline to side.
Starts using self comforting skills, i.e. sucking hands and position. Is able to resist movement some.
Has more defined sleep/wake states.
Sleeps more soundly.
May wake before feeds.
Is having continued improvement with lid tightening for light protection. Infant may focus on something for a period of time but quickly becomes over stimulated and may have some signs of disorganization. May have difficulty breaking a gaze on a stimulation object. Starts being able to track horizontally at about 35 weeks. Eyes movement still may appear uncoordinated.
Behavior to sound becomes more individualized. Responses more consistent and organized.
Skin remains delicate.
Starts to tolerate more and different kinds of stimulation. i.e. stroking.
Begins to nipple feed.
Is capable to gentle social interaction. May become over stimulated with more then one kind of socialization at a time.
Behavioral organization and self-regulation really improving.
36 to 40 Weeks
Should be able to maintain own temperature.
Respiratory rate 30-60 should not require mechanical ventilation unless sick.
Heart rate 120-160 beats per minute.
Sleeps well flexed. Moves all extremities in a wide variety of motions. Strong resistance to passive movement of extremities. Well defined sleep and wake states. Clearly alert states for social interaction. Shows preference to seeing the human face. Sees 8-10 inches from his/her face. Active looking noted during this time.
May become disorganized with lengthy periods of socialization.
Likes the sound of the human voice. More consistent behaviors around sound. Still become disorganized with lengthy or loud noises.
Skin still a bit delicate. Increased tolerance for gentle handling.
Still may become disorganized with painful stimulation.
Becomes more actively involved with parents/care givers.
