High fever following postpartum administration of sublingual misoprostol

OBJECTIVE: To explore what triggers an elevated body temperature of ≥40.0°C in some women given misoprostol, a prostaglandin E1 analogue, for postpartum haemorrhage (PPH). DESIGN: Post hoc analysis. SETTING: One tertiary-level hospital in Quito, Ecuador. POPULATION: A cohort of 58 women with a fever of above 40°C following treatment with sublingual misoprostol (800 micrograms) for PPH. METHODS: Side effects were documented for 163 Ecuadorian women given sublingual misoprostol to treat their PPH. Women’s body temperatures were measured, and if they had a fever of ≥40.0°C, measurements were taken hourly until the fever subsided. Temperature trends were analysed, and the possible physiological mechanisms by which postpartum misoprostol produces a high fever were explored. MAIN OUTCOME MEASURES: The onset, duration, peak temperatures, and treatments administered for cases with a high fever. RESULTS: Fifty-eight of 163 women (35.6%) treated with misoprostol experienced a fever of ≥40.0°C. High fevers followed a predictable pattern, often preceded by moderate/severe shivering within 20 minutes of treatment. Body temperatures peaked 1–2 hours post-treatment, and gradually declined over 3 hours. Fevers were transient and did not lead to any hospitalisation. Baseline characteristics were comparable among women who did and did not develop a high fever, except for known previous PPH and time to placental expulsion. CONCLUSIONS: An unexpectedly high rate of elevated body temperature of ≥40.0°C was documented in Ecuador following sublingually administered misoprostol. It is unclear why temperatures ≥40.0°C occurred with a greater frequency in Ecuador than in other study populations using similar treatment regimens for PPH. Pharmacogenetic studies may shed further light on variations in individuals’ responses to misoprostol.