///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Association between intrapartum magnesium administration and the incidence of maternal fever: a propensity analysis

Abstract Number: SAT-43
Abstract Type: Original Research

Elizabeth M S Lange MD1 ; Scott Segal MD2; Carlo Pancaro MD3; Cynthia A Wong MD4; Gregory B Russell MS5; Paloma Toledo MD, MPH6

Introduction: Maternal fever, defined as a temperature ≥ 38° C (100.4° F), is associated with several adverse neonatal outcomes. An association between the use of intrapartum neuraxial analgesia and maternal fever exists, possibly mediated by interleukin-6 (IL-6). In a rat model, magnesium sulfate suppressed IL-6-induced increases in maternal temperature. Retrospective data suggest a decreased incidence of maternal fever in women receiving magnesium. We hypothesized that patients exposed to intrapartum magnesium would have a lower incidence of fever than those patients not exposed.

Methods: In this retrospective, cross-sectional study, electronic medical record data from all deliveries at Northwestern Memorial Hospital between 2007 and 2014 were queried. Cases without temperature data and without intent for vaginal delivery were excluded. Extracted data included parity, gestational age, labor type, membrane status, mode of delivery, the use of neuraxial analgesia, diagnosis of preeclampsia, and magnesium sulfate administration. Using this data set a propensity score model was created to evaluate the association between magnesium and fever. Propensity score matching was used to reduce potential bias from non-random selection of magnesium administration. Only cases in which there were no missing data were used for propensity analysis.

Results: A total of 58,541 women met inclusion criteria; 1179 received magnesium. Fifty-seven patients were missing at least one variable and could not be matched for propensity scoring. Using a caliper method to set the maximum acceptable distance between score matches, 959 (85.5%) of 1122 subjects were matched in a 1:1 fashion with a non-recipient. Fisher’s exact tests were used to test the balance between study groups in the propensity model; no comparison P-values were less than 0.05. Using the total sample of 1918 subjects, the relationship between fever and magnesium was modeled using a logistic regression. The odds ratio in the single variable model was 0.68 (95% CI of 0.48 to 0.98).

Conclusions: Our data suggest that magnesium is associated with a lower incidence of maternal fever. Future work should evaluate the association between the duration of magnesium administration and the development of fever, as well as evaluate neonatal outcomes. These findings should be validated in prospective study, in order to inform the use of magnesium as a potential intervention.

SOAP 2017