ABSTRACT
Myometrial strips were taken from the lower segment of 20 parturients undergoing low transverse caesarean section. Nine were in latent phase and 11 were in active phase of labor. Each strip was divided into 2-8 small strips of equal size. The pattern of isotonic contraction in vitro was observed. Spontaneous contraction, showing viability of the strips, could be obtained in 83.70 percent of total of 49 strips from the latent phase parturients and in 90.40 percent of a total of 52 strips from the active phase parturients. The period of contraction was the only parameter analysed to demonstracte the active phase parturients. The period of contraction was 11.33+6.31 minutes in the latent phase group and 11.99+5.23 minutes in the active phase group. The data showed no statistically significant difference by the Wilcoxon rank-sun test (p=0.425). In conclusion, the pattern of contraction of the myometrial strips from the lower segment of human term pregnant uterus in vitro was the same in the latent phase as in the active phase. Further study is suggested to confirm and further investigate the aetiologies of this finding.