Katz Z, Lancet M, Dgani R, Ben-Hur H, Zalel Y
Acta Obstet Gynecol Scand. 1982;61(4):337-40.
The vacuum extractor (VE) was applied electively after approximately 25 min of expulsion in 25 normal primiparae. Twenty-five identical parturients with spontaneous deliveries served as controls. The fetal scalp pH was measured at the beginning of the 2nd stage, and again in the cord blood of all newborns. Cardiac monitoring by scalp electrode was done for all fetuses throughout labor. The mean pH of the first blood sample was almost identical in the two groups, while the mean decrease in pH in the VE group was 0.077, against a mean change of 0.106 in the controls (p less than 0.05). In the FHR graph the total area of deceleration, and separately in the controls (p less than 0.05). In the FHR graph the total area of deceleration, and separately the up to 30 beats/min (area A) and of more than 30 beats/min (area B) were calculated. The mean total area of deceleration in the VE group was 14.76 cm2vis-à-vis 17.56 cm2 in the controls. Areas A and B were also smaller in the study group, but these differences were not statistically significant. The mean total deceleration time in the VE fetuses was 22.8 min, and 37.75 min in the controls (p less than 0.001). It is concluded that the application of the VE during the second stage lessens fetal depression, when compared with spontaneous delivery.
