Antenatal Magnesium and Cerebral Palsy in Preterm Infants

Abstract

Objective To evaluate the relationship of maternal antenatal magnesium sulfate (MgSO4) with neonatal cranial ultrasound abnormalities and cerebral palsy (CP). Study design In a randomized trial of MgSO4 or placebo in women at high risk of preterm delivery, up to three cranial ultrasound were obtained in the neonatal period. Images were reviewed by at least two pediatric radiologists masked to treatment and other clinical conditions. Diagnoses were predefined for intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), intracerebral echolucency or echodensity, and ventriculomegaly. CP was diagnosed at two years by standardized neurological examination. Results Intraventricular hemorrhage, PVL, intracerebral echolucency or echodensity, and ventriculomegaly were all strongly associated with an increased risk of CP. MgSO4 administration did not affect the risk of cranial ultrasound abnormality observed at 35 weeks post-menstrual age or later. However, for the 82% of infants born at <32 weeks gestation, MgSO4 was associated with a reduction in risk of echolucency or echodensity. The reduction in risk for echolucency explained 21% of the effect of MgSO4 on CP (p=0.04), and for echodensity explained 20% of the effect (p=0.02). Conclusions MgSO4 given prior to preterm delivery was associated with decreased risk of developing echodensities and echolucencies at <32 weeks gestation. However, this effect can only partially explain the effect of MgSO4 on CP at two years of age.

Reduced Prevalence of Severe Intraventricular Hemorrhage in Very Preterm Infants Delivered after Maternal Preeclampsia

“…The preventive effect on CP was only partly mediated by a reduction in cranial ultrasound abnormalities in the neonatal period [19]. Maternal treatment with a β-blocker and MgSO 4 has been shown to alter neonatal cerebral hemodynamics which may modify the risk of IVH [20].…”

Antenatal Exposure to Magnesium Sulfate Is Associated with Reduced Cerebellar Hemorrhage in Preterm Newborns

“…4–6 A recent study has shown that antenatal magnesium sulfate is associated with a reduced risk of white matter echolucencies and echodensities on cranial ultrasound; however, this effect only partially explains the reduction of cerebral palsy among exposed newborns. 7 Antenatal exposure to magnesium sulfate has not been associated with a reduction in brain injuries known to cause cerebral palsy, such as cystic white matter injury or intraventricular hemorrhage (IVH), in several randomized controlled trials that used ultrasound to diagnose brain injury. 8–12 The underlying explanation for the neuroprotective effects of magnesium sulfate in premature newborns is unclear, and further investigation for brain injury with magnetic resonance imaging (MRI) may help clarify this.…”

Antenatal Betamethasone: A Prolonged Time Interval from Administration to Delivery Is Associated with an Increased Incidence of Severe Intraventricular Hemorrhage in Infants Born before 28 Weeks Gestation

“…We were unable to reliably collect data about them during the early phases of their implementation and therefore have not included them in our data set. However, as of this time, neither antenatal Magnesium (38, 39) nor delayed cord clamping (40) has been shown to alter the incidence of severe IVH in preterm infants. It is possible that our study was underpowered to detect small differences in neonatal outcomes; the number of infants that delivered ≥10 days after the first dose of BMZ was small and the cohort that received a second course of steroids was even smaller.…”