A patient was induced for being post-term at 4237 weeks. Immediately following the delivery, you examine the baby with the pediatricians and note the following on physical exam: a small amount of cartilage in the earlobe, occasional creases over the anterior two-thirds of the soles of the feet, 4-mm breast nodule diameter, fine and fuzzy scalp hair, and a scrotum with some but not extensive rugae. Based on this physical exam, what is the approximate gestational age of this male infant?

An estimate of the gestational age of a newborn can be made rapidly by a physical exam immediately following delivery. Important physical characteristics that are evaluated are the sole creases, breast nodules, scalp hair, earlobes, and scrotum. In newborns that are 39 weeks gestational age or more, the soles of the feet will be covered with creases, the diameter of the breast nodules will be at least 7 mm, the scalp hair will be coarse and silky, the earlobes will be thickened with cartilage, and the scrotum will be full with extensive rugae. In infants that are 36 weeks or less, there will be an anterior transverse sole crease only, the breast nodule diameter will be 2 mm, the scalp hair will be fine and fuzzy, the earlobes will be pliable and lack cartilage, and the scrotum will be small with few rugae. In infants of gestational age between 37 and 38 weeks, the soles of the feet will have occasional creases on the anterior two-thirds of the feet, the breast nodule diameter will be 4 mm, the scalp hair will be fine and fuzzy, the earlobes will have a small amount of cartilage, and the scrotum will have some but not extensive rugae.