Background: Although elective cesarean sections are often performed after the 37th week of gestation without any complicating factor that may influence the timing of delivery,there is a possibility that infants born in the 37th week of gestation,especially early in the 37th week of gestation, do not obtain a satisfactory clinical outcome due to premature birth.
Methods: The authors analyzed the clinical course during the neonatal period in 96 infants born in the 37th (n = 81)and 38th (n = 15) week of gestation by an elective cesarean section. Subjects were retrospectively divided into two groups: infants born in the first half of the 37th week of gestation (37+0-37+3)(n = 48), and infants born from the latter half of the 37th week of gestation (37+4-37+6)through the 38th week of gestation (n = 48). Twin pregnancies, pregnancy with placenta previa, and pregnancy of women who had a diversity of medical complications were excluded from the present study, because of the possibility that these conditions may have affected the infants' status. The incidence of infants who showed clinical symptoms during the neonatal period and who needed medical care was compared between the two groups.
Results: Of the 96 subjects, 25 infants(26.0%) had significant clinical symptoms. The incidence of breathing difficulty was significantly higher in the infant group born in the first half of the 37th week of gestation than in the latter group.
Conclusions: An elective cesarean section before the onset of labor early in the 37th week of gestation should not be routinely undertaken.