Retrospective study of fetal effects of prolonged labor before cesarean delivery

Three hundred fifty-two cesarean operations were done at Huron Road Hospital in the years 1952-1954. Examination of family records identified 97 probands delivered by cesarean after prolonged active labor before or during that period. Research efforts yielded 54 cases that were free of complications and had full historic data for both proband and sibling(s) of the same parentage, totaling 122 children. The intelligence quotient (IQ) scores of these families compared with that of the proband undergoing successive hours of labor suggested a detrimental effect of increasing length of trial labor. Statistical analyses of the 30 families in which the probands' trial labors exceeded 12 hours support that notion, as the probands had significantly lower IQ scores than their siblings born by elective cesarean with no labor (P = .006 to P less than .001). Probands had the lowest IQ scores in their families significantly more often (P less than .025) than could be expected to occur randomly. A similar pattern of school success occurred within the families.