What are expected physical observations of an infant born at 42 weeks gestation?

An infant born at 42 weeks gestation is classified as post-term, meaning they have been inside the womb longer than the typical 40 weeks of pregnancy. As a result, their skin often appears less smooth and more wrinkled than that of a baby born closer to the expected term. This wrinkling occurs because the skin has had more time to desquamate, or shed its outer layer, and also due to the reduction in the amount of vernix caseosa (the protective coating on the skin) that naturally occurs as gestation progresses beyond the usual timeframe.

This physical characteristic aligns with the typical observations made in post-term infants, where the skin's appearance can reflect the prolonged exposure to the amniotic fluid environment. Therefore, noticing wrinkled skin in these infants indicates their extended gestational duration, making this observation consistent with the expected developmental characteristics of a post-term baby.