Meconium aspiration syndrome is responsible for substantial morbidity and mortality, and its incidence increases regularly between 38+0 and 42+6 weeks, from 0.24% to 1.42% (grade B).
Similarly, the risks of neonatal acidosis (grade B), 5-min Apgar scores less than 7 (grade B) and admissions to neonatal intensive care (grade B) increase progressively between 38+0 and 42+6 weeks.
These risks appear to double for postterm growth-restricted newborns (grade C). Post-term newborns have an increased risk of neurologic complications such as neonatal convulsions (risk multiplied by 1.5) (grade B), anoxic-ischemic encephalopathy (grade C), cerebral motor disorders (risk multiplied by 2.4) (grade
B), psychomotor developmental disorders (risk multiplied by 2.2) (grade C) and childhood epilepsy (risk multiplied by 1.9) (grade B), but these complications cannot be directly attributed to the postterm
status. The absolute incidence of these risks nonetheless remains low.