Gestational Age vs. Age by Exam

[babaloo, BSN]

Can someone explain the difference in these two? Once a baby is born, is gestational age the estimated age from Last Menstrual Period to the date of birth? And what exam is done for the age by exam? What's the difference between age by exam and gestational age?

[NurseNora, BSN, RN]

Gestational age figured by EDC is accurate to plus or minus two weeks. That assumes the woman has regular cycles, keeps track of her periods and remembers the date of her last period, and didn't miss a period before conception or have some bleeding after conception. U/S done early can pin the date more accurately, but does depend on the skill of the ultrasonographer. The later it is done, the less accurate it is.

After birth, the Ballard Score is done to assess the baby's maturity by systematically evaluating the infant's physical body. Thickness of ear cartilage, size of breast buds, amount of lanugo, muscle tone and resistance among other things are evaluated then added up to get the score. Go to U tube to see this being done.

[klone, MSN, RN]

Age by exam is useful if LMP is uncertain, or if the infant appears developmentally immature, compared to how old the baby "should" be. It can also help guide care, if the infant's age by exam is only 36 weeks, then you might anticipate some feeding difficulties or difficulties with thermoregulation.