The normal human gestation period from the time of conception until birth ranges between 37-42 complete weeks. Babies born between these periods are called full term babies. However, babies who are born before the 37th completed week of the usual cycle are referred to as premature baby survival rate.

1. A synopsis of premature baby survival rate
The normal human gestation period from the time of conception until
birth ranges between 37-42 complete weeks. Babies born between
these periods are called full term babies. However, babies who are
born before the 37th completed week of the usual cycle are referred to
as premature baby survival rate.
Statistics for pre mature/ preterm births:
Studies reveal that in the United States alone about 12% of babies
born every year are premature.
Nearly 70% of preterm births occur between the 34 and the 36
completed week of gestation. Usually babies born in this time period
are delivered through a C-section.
Around 12% of preterm births occur between the 32nd and the 33rd
week of gestation and chances drop to about 10% between the 28th
and the 31s week of pregnancy and further fall to about 6% for
preterm births occurring at less than 28 weeks of gestation.

2. Let’s look into premature baby survival rate:
Gestation period Survival rate
32nd – 33rd week 95%
28th – 31st week 90-95%
27th week 90%
26th week 80%
25th week 50%
24th week 39%
23rd week 17%

3. Why do preterm births occur?
A majority of the preterm births occur on account of preterm labor which
is self induced or owing to early breakage of the placenta also referred to
as PROM – Premature rupture of the membrane. Though the exact causes
of PROM and preterm labor are not fully understood some of the factors
which lead to preterm births are as follows:
History of previous preterm birth
Development of bacterial infections such as vaginosis.
Shortened cervix
Sedentary lifestyle of the mother such as intake of alcohol, drugs, etc
Severe stress and a lack of social well being
Certain medical conditions of the mother like diabetes, high blood
pressure levels, obesity or severely underweight prior to pregnancy
Vaginal bleeding
Short spacing between pregnancies.

4. What factors determine the chances of premature baby survival rate?
Gestational age during birth:
The most important factor in the context of the odds of the premature
baby surviving is dependent on the gestational age during birth.
Baby weight:
Preterm babies who weigh as low as 2.2 Ibs at birth have very less survival
rate. Low birth weight may be due to failure of complete development of
certain organs like the lungs, the brain, etc.
Signs of respiratory ailments:
In the absence of signs of any respiratory ailments, the baby may survive
without much disability.
Birth defects:
If the child is not suffering from any kind of birth defect or abnormalities,
intensive care can help to improve the survival rate and the overall health
condition of the baby.
In conclusion, premature babies undoubtedly pose the risk of developing
health complications and a common observation is that the earlier the
preterm birth, the lesser is the premature baby survival rate and if the
baby manages to survive it may run the risk of developing severe ailments
either immediately after birth or at a later period.