Intrauterine temperature during intrapartum amnioinfusion: a prospective observational study

Please cite this paper as: Tomlinson T, Schaecher C, Sadovsky Y, Gross G. Intrauterine temperature during intrapartum amnioinfusion: a prospective observational study. BJOG 2012;119:958–963. Objective  To determine the influence of routine intrapartum amnioinfusion (AI) on intrauterine temperature. Design  Prospective observational study. Setting  Maternity unit, Barnes Jewish Hospital, St Louis, MO, USA. Sample  Forty women with singleton gestations and an indication for intrapartum intrauterine pressure catheter placement. Methods  Using a temperature probe, we digitally recorded intrauterine temperature every 10 minutes during labour. Amnioinfusion was administered according to a standard protocol using saline equilibrated to the ambient temperature. Main outcome measure  Mean intrauterine temperature during labour. Results  Participants were monitored for a mean of 280 minutes (range 20–820). A total of 164 intrauterine temperature readings in the AI cohort were compared with 797 control measurements. When compared with controls, we observed a lower intrauterine temperature in the AI cohort (36.4 versus 37.4°C, P < 0.01). More measurements in the AI cohort were recorded in the presence of intrapartum fever (40% versus 30%). A subgroup analysis of measurements recorded in afebrile parturients revealed an even greater effect of AI (1.5°C decrease, 37.3 versus 35.8°C, P < 0.01). Conclusion  Routine intrapartum AI using saline equilibrated to a mean ambient temperature of 25.0°C reduces intrauterine temperature and may thereby affect fetal core temperature.