RT Book, Section A1 Gomella, Tricia Lacy A1 Eyal, Fabien G. A1 Bany-Mohammed, Fayez SR Print(0) ID 1168355598 T1 Gestational Age and Birthweight Classification T2 Gomella's Neonatology: Management, Procedures, On-Call Problems, Diseases, and Drugs, 8e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781259644818 LK accesspediatrics.mhmedical.com/content.aspx?aid=1168355598 RD 2024/03/28 AB Gestation is the period of fetal development from the time of conception to birth. Gestational age (or menstrual age), as defined by the American Academy of Pediatrics (AAP), is the “time elapsed between the first day of the last menstrual period (LMP) and the day of delivery.” It is expressed in completed weeks (26-week and 4-day-old fetus is expressed as a 26-week fetus). Gestational age is important information for the obstetrician to provide obstetric care. It is critical information for the neonatologist for evaluation of the infant and to anticipate high-risk infants and complications. Gestational age and birthweight classification help the neonatologist to categorize infants, guide treatment, and assess risks for morbidity and mortality. Neonates can be classified based on gestational age (preterm, late preterm, early term, full or late term, post term), birthweight (eg, extremely low birthweight, very low birthweight, low birthweight), and gestational age and birthweight combined (small for gestational age [SGA], appropriate for gestational age [AGA], large for gestational age [LGA]). The AAP recommends that all newborns be classified by birthweight and gestational age.