• Postmaturity, taken as meaning a gestational age of 294 days or more, occurred 247 times in a series of 2,877 deliveries. Gestational age exceeded 299 days in 132 of these babies.
The postmature group did not differ significantly, as to average weight and body length, from a group of 252 babies born after the 259th and before the 295th day. The postmature group did, however, include 11 infants with one or more clinical findings characteristic of a placental dysfunction syndrome: dry, scaling, parchment-like skin; staining of the skin and vernix caseosa; and poor tissue turgor, subcutaneous tissue wasting, or other evidence of recent weight loss. Four cases of this are described in some detail. In the full-term group, on the other hand, there was only one infant with any findings consistent with this picture.
Perinatal mortalities in these two groups did not differ significantly. The evidence indicated that postmature babies at birth must weigh, on the average, somewhat less than the maximum they attain before birth and that their intrauterine growth is limited by the functional capacities of the placenta.
Kunstadter RH, Schnitz SE. POSTMATURITY AND THE PLACENTAL DYSFUNCTION SYNDROME. JAMA. 1956;161(16):1551-1555. doi:10.1001/jama.1956.02970160031007