Gestational age is the number of days and weeks that measure the length ofpregnancy.
It helps healthcare providers determine your due date.
Learn about gestational age, how to calculate it, tracking pregnancy, and more.
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Gestational age measures the age of gestation (pregnancy), not the age of thefetus.
Conception occurs during (and shortly after) ovulation, a time frame known as thefertility window.
Experts use a 28-day cycle to calculate gestational age based on the average menstrual cycle length.
After that, it is generally counted in weeks plus the number of days past the previous week.
These calculators may also provide an estimated due date to predict the baby’s birth date.
Use this date as an estimate only, especially if you have not been tracking your menstrual period.
The first day of the last menstrual period is accurately remembered and used only about half the time.
Regardless of how the due date is calculated, the baby may be born before or after that date.
It is referenced regularly throughout pregnancy.
However, it is not technically the age of the baby.
This is because the gestational age is calculated starting with the first day of the last menstrual period.
Conception generally happens about two weeks after that, but it may occur earlier or later than this average.
While the estimated delivery date is 40 weeks gestation, that estimate is not always accurate.
Providers may use gestational age to assess the developmental milestones of babies born before 37 weeks gestation.
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