87 - Antenatal exposure to magnesium sulphate and neonatal outcomes in very low birth weight infants: a multicenter study

Poster Number: 87
Publication Number: 87.438

Catalina Vaz Ferreira, Pereira Rossell Childrens Hospital, Montevideo, Montevideo, Uruguay; Jose J. Caro, GENERAL HOSPITAL, PUERTO VARAS, Los Lagos, Chile; Gerardo H. Flores, Hospital Puerto Montt, Puerto Montt, Los Lagos, Chile; Patricia C. Alvarez, Hospital Puerto Montt, Puerto Montt, Los Lagos, Chile; Sergio R. Munoz, Universidad de La Frontera, Temuco, Araucania, Chile; Tamara I. Herrera, 36436512, Montevideo, Montevideo, Uruguay; Alberto Toso, Pontificia Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile; Paulina Toso, Pontificia Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile; Jose L L. TAPIA, Pontificia Universidad Católica de Chile, SANTIAGO, Region Metropolitana, Chile

Background:
Antenatal magnesium sulphate (MgSO4) is widely used in obstetric practice for preeclampsia and fetal neuroprotection in women at risk of preterm delivery. Recent studies suggest that antenatal MgSO4 is associated with favourable neurodevelopmental outcomes in preterm infants < 32 weeks gestational age (GA). However, there are concerns regarding the safety of in utero MgSO4 exposure, particularly an increased risk of death and other adverse neonatal outcomes. 

Objective: To explore the effects of antenatal MgSO4 on neonatal mortality and the incidence of intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants.

Design/Methods: Retrospective, multicenter cohort study, with prospective data entry and predefined diagnostic criteria of all preterm infants < 32 weeks GA and < 1500g born at centers of the NEOCOSUR Neonatal Network between January 2015 and December 2020. Subjects were categorized as exposed vs non-exposed to antenatal MgSO4. Primary outcome was death and incidence of severe IVH (Grade III-IV) in both groups of infants. Secondary outcomes included other major neonatal morbidities. A multiple logistic regression analysis was performed to adjust for main cofounders.

Results: A total of 7.483 VLBW infants were eligible and followed until death or hospital discharge. Main biodemographic characteristics and outcomes are shown in tables 1 and 2. Magnesium-exposed infants were delivered at a significantly lower GA compared to non-exposed infants (27.8  ± 2.1 vs. 28.2  ± 2.0 weeks, p < 0.001). Multivariate analysis showed that antenatal MgSO4 was associated with a significantly decreased risk of death in delivery room and after admission (aOR 0.36, 95% CI 0.18-0.72 and aOR 0.71, 95% CI 0.62-0.82 respectively). Similarly, exposure to antenatal MgSO4 was associated with a significant reduction in severe IVH (aOR 0.86, 95% CI 0.76–0.98). No differences between groups were observed in the rates of other major neonatal morbidities such as sepsis, patent ductus arteriosus,  global IVH, necrotizing enterocolitis, periventricular leukomalacia, retinopathy of prematurity, and bronchopulmonary dysplasia. Conclusion(s): In this large multicenter study, antenatal MgSO4 was associated with a decreased risk of death (both in DR and after admission) and severe IVH in VLBW infants. However, these results should be interpreted with caution as they may represent an overall improved antenatal care. Therefore, we believe our most important finding is the lack of in-hospital adverse effects in VLBW infants whose mothers received MgSO4.
Table 1. Baseline perinatal biodemographic characteristics of MgSO4 exposed and non-exposed patients (NEOCOSUR 2015-2020).
Table 2. Neonatal interventions and outcomes of MgSO4 exposed and non-exposed patients (NEOCOSUR 2015-2020[JJCM1] ).