Gest age is gestational age and is a term that is used to describe how far along you are in your pregnancy.
Gest age is measured in weeks from the first day of your last menstrual period to the current date.
Normal pregnancies last around 38 weeks to 42 weeks and babies born before 37 weeks are considered to be premature babies.
Your gestational age is based on the date of your last period, and not the date of your conception.
As a result a woman is usually considered at least 4 weeks pregnant by the time they actually miss a period and have a positive pregnancy test.
Fetal age is the actual age of the growing baby.
Gestational age is a key piece of data used by doctors and nurses to determine the timing of various screening tests and assessments of the fetus and mother throughout pregnancy.
It is possible for gestational age to be inaccurate by up to 2 weeks, even with an accurate LMP date confirmed by other tests.
For premature babies the baby's corrected age is the age the baby would be if they had been born on their due date, instead of being born premature.
For example, if the baby was born 3 months early and it is now 7 months from the baby's birth, the baby's corrected age is 7 months minus 3 months, giving a corrected age of 4 months.