Gestational age assessment
Measurement of gestational age. The length of time from the first day of the mother’s last menstrual period until the time of delivery. Since the health of the baby after birth is related to gestational age, estimating gestational age is critical to both obstetrical management of the mother and neonatal management of the infant.
Estimates of gestational age in pregnancy have improved greatly over the past decade. With artificial insemination, in vitro fertilization and related techniques, the gestational age can be measured to within hours. In all pregnancies, ultrasound measurements early in pregnancy can estimate gestational age to within days. After birth an examination of the infant usually permits measurement of gestational age to within a week or so; however, the techniques for assessing gestational age do not work well in extremely premature infants (<26 weeks gestational age).