Premature/preterm/prem baby

A baby who has been born before spending 37 weeks in the womb.

Gestational age (GA)

The amount of time your baby has spent in your womb.If he or she is 25 weeks gestational age he has spent 25 weeks growing inside you. this means he is about 15 weeks early,as most babies arrive between 38 and 41 weeks GA.

Extremely Premature

Born having spent 24 to 28 weeks in the womb.

Very premature 

Born having spent 29 to 34 weeks in the womb.                                                  

Moderately premature 

Born having spent 35 to 37 weeks in the womb.

Low birth weight baby

A baby who weighs less than 2,500g (5 -1/2 lb) at birth .Most premature babies are also low birth weight. However the to terms do not mean the same thing,because some babies can spend all 40 weeks in the womb,but still be smaller than usual when they arrive.

Very or extremely low birth weight baby

A baby born weighing less than 1.361g (3lb)

Term baby

A baby who has spent the full amount of time developing in the womb between 38 and 41weeks

Viability limit

How early a premature baby can be born and still live.Different hospitals have slightly different limits for the age at which they feel a premature baby can be helped.Although a weeks.very few babies have survived after being born at 22 weeks,viability limits usually fall some where between 23 and 25 weeks.