Factors related to perceived labor pain in primiparas

The purpose of this study was to investigate the association between demographic-obstetric factors and perceived labor pain in primiparas. The participants in this study were 90 primiparas having normal childbirths at the Department of Obstetrics, Chi-Mei Medical Center in southern Taiwan between September 1999 and June 2000. The perceived intensity of labor pain was measured using the visual analogue scale for pain and the present behavioral intensity score in the latent phase (cervix dilated 3-4 cm), active phase (cervix dilated 5-7 cm), and transitional phase (cervix dilated 8-10 cm). The subjects' mean age was 27.82 +/- 3.64 years (range, 20-39 yr), and the mean newborn birth weight was 3,162 +/- 387 g (range, 2,340-4,120 g). The primiparas' perceived labor pain at each of the three phases of labor was positively related to expected labor pain, but had no significant association with newborn birth weight, maternal age, body mass index, confidence in labor, or duration of labor. The expected labor pain of the primiparas had a negative correlation with body mass index. The birth weight of the newborn was positively related to the duration of labor. These findings suggest that primiparas' perceived labor pain is correlated with psychogenic rather than physical factors.