Postpartum chills phenomenon: is it a feto-maternal transfusion reaction?
OBJECTIVE: To examine the theory that the postpartum shivering phenomenon is related to feto-maternal bleed during the third stage of labor. METHODS: One hundred laboring low-risk women who had a normal vaginal delivery were observed for the presence of postpartum chills. The duration of the first and second stages of labor changes in body temperature, maternal and fetal blood types and the use of epidural anesthesia were recorded. Following the delivery maternal blood was examined for the presence of fetal red blood cells using the Kleihauer-Betke stain. RESULTS: Complete data was available in 97 patients. Post-partum chills occurred in 31 of them (32%). Women with and without chills were similar in their maternal and gestational age, the use of epidural anesthesia, and length of second stage of labor. Women with chills delivered smaller babies but the difference did not reach significance. Maternal-fetal blood group incompatibility was significantly more common among shivering than non-shivering women (48% vs. 20% respectively, p=0.006). Kleihauer-Betke test was positive in 11 women. The only two women in this group who experienced chills had maternal-fetal blood group incompatibility. CONCLUSION: Post-partum chills are a common phenomenon. It may be the clinical presentation of feto-maternal transfusion reaction. The small number of positive Kleihauer-Betke tests may reflect its low sensitivity in the detection of small feto-maternal bleeds.