Observations on the postpartum shivering phenomenon

Fifty healthy, nonmedicated, laboring women who had normal spontaneous vaginal deliveries were studied to determine the incidence, time of onset, severity, duration, temperature patterns and relationship of various perinatal factors to the postpartum shivering phenomenon. Axillary temperature was recorded on admission, before delivery, at delivery and every 15 minutes postpartum for 75 minutes. The degree and duration of shivering were quantified visually. The environmental temperature was recorded. Of the 50 women, 22 (44%) commenced shivering during delivery or up to 30 minutes postpartum. Shiverers and nonshiverers exhibited a reduction in the mean axillary temperature during labor, with a rise post-partum (P less than .002). The median axillary temperature of the shiverers at all time points was higher than that of the nonshiverers and was statistically significant 30 (P less than .01), 45 (P less than .003), 60 (P less than .004) and 75 minutes (P less than .001) after delivery. The shiverers tended to raise their postdelivery temperature somewhat later than did the nonshiverers. The temperature pattern of both shiverers and nonshiverers fell during labor, and the temperature pattern of the shiverers differed from that of the nonshiverers postpartum. The mean delivery room temperature for shiverers was lower than for nonshiverers (P less than .009), as was the mean recovery room temperature (P less than .03). Environmental temperature may play a heretofore unsuspected role in the postpartum shivering phenomenon.