Increased Risk of Meconium-Related Ileus in Extremely Premature Infants Exposed to Antenatal Magnesium Sulfate

Abstract

<b><i>Introduction:</i></b> We experienced an increased incidence of meconium-related ileus (MRI) in extremely premature infants (EPIs) while adopting the antenatal magnesium sulfate (MgSO₄) protocol for fetal neuroprotection in our neonatal intensive care unit. This study aimed to test whether antenatal MgSO₄ use was associated with increased risk of MRI in EPIs. <b><i>Methods:</i></b> The incidences of complicated MRI requiring aggressive enema or surgical intervention and other intestinal complications were compared among period 1 (January 2012–December 2013, <i>n</i> = 79), before adoption of the antenatal MgSO₄ protocol for fetal neuroprotection; period 2 (January 2014–March 2016, <i>n</i> = 72), when the protocol was adopted; and period 3 (April 2016–September 2018, <i>n</i> = 75), when the protocol was temporarily withdrawn due to concern regarding intestinal complications in EPIs. <b><i>Results:</i></b> Despite similar baseline clinical characteristics among infants across the study periods, the MRI and MRI with surgical treatment incidences were higher in period 2 than those in periods 1 and 3 (13% vs. 8% and 6%, <i>p</i> = 0.391, and 11% vs. 0% and 1%, <i>p</i> = 0.001, respectively). In multivariable analysis, exposure to antenatal MgSO₄ independently increased the risk of MRI (adjusted odds ratio, 3.8; 95% confidence interval, 1.4, 10.6). <b><i>Conclusion:</i></b> Antenatal MgSO₄ may increase the risk of MRI, frequently requiring surgical intervention, in EPIs with a gestational age of 25 weeks or less.