A preliminary study of cutaneous blood flow associated with postpartum use of oral misoprostol

To evaluate cutaneous blood flow, as identified by Doppler fluximetry, to understand the etiology of shivering associated with the postpartum use of oral misoprostol.

Eligible participants were recruited from a group of women who were enrolled in an ongoing randomized trial comparing 400 microg of oral misoprostol to 5 IU of intravenous oxytocin for postpartum hemorrhage prophylaxis. The laser Doppler fluximeter was used to noninvasively measure changes in peripheral tissue perfusion (flux). A skin probe attached to the upper arm recorded flux and skin temperature. Baseline levels were obtained before delivery and for 30 minutes postpartum (maximum flux) after the women received the study drug. Continuous variables were analyzed with Student t-test or paired t-test, with the Wilcoxon signed rank test used for non-parametric ordinal data. Categoric data were analyzed with the chi-square test or Fisher's exact test.

Sixteen women were enrolled, and 10 women had a vaginal delivery and received the study drugs. Among these 10 women, a significant difference between baseline and maximum flux levels was demonstrated for both women treated with oxytocin (P = .04) and for those treated with misoprostol (P = .04). Women treated with oxytocin also had a significant change in skin temperature (P = .04). Maximum flux levels were not significantly different between the women receiving misoprostol compared with those receiving oxytocin (P = .42).

Shivering associated with oral misoprostol may not be due to a resetting of the hypothalamic thermoregulatory centre. Further study is needed to determine whether shivering associated with oral misoprostol is dose-dependent or related to locally mediated phenomena.