Maternal Antenatal Magnesium Does Not Prevent Retinopathy of Prematurity (ROP) or Severe Head Ultrasound (HUS) Abnormalities in Very Low Birth Weight Premature Infants-Severe HUS Abnormalities and ROP Are Significantly Related

Abstract 1080 Poster Session IV, Tuesday, 5/4 (poster 258)

Introduction: Recently, retrospective analyses have suggested a neuroprotective effect of maternal prenatal magnesium therapy preventing brain injury in premature newborn infants. We have previously reported a significant correlation between the presence of severe intracranial hemorrhage (ICH) and/or cystic periventricular leukomalacia (CPVL), and the subsequent development of severe retinopathy of prematurity (ROP). We therefore considered the hypothesis that maternal prenatal magnesium therapy might also reduce the risk of developing significant ROP.

Methods: All very premature infants (<1,500 grams at birth, <32 weeks gestation) discharged from our hospital between January, 1997 and March, 1998 were included for this study (N=108 survived of 134 admitted to the nursery). Our computerized clinical database was reviewed retrospectively. Maternal prenatal magnesium therapy was coded yes/no, and two study groups defined. HUS images were coded for presence/absence of severe (grade 3 or 4) ICH, and CPVL. Ophthalmologic examinations were coded for presence/absence of severe ROP (stage 3 or 4 disease, and/or laser surgery required), and prethreshold disease (International Classification-ROP).

Results: Survivors had mean birth weight 960±280 SD grams, gestation 27±2.5 weeks. Severe ROP occurred in 41% of infants with severe ICH/CPVL, but only 19% of infants without severe brain injury (P=0.03). Prethreshold disease occurred in 27% of infants with severe ICH/CPVL, but only 8% of infants without severe ICH/CPVL (P=0.02). Maternal magnesium therapy did not significantly ameliorate the occurrences of severe ROP, prethreshold disease, and severe ICH/CPVL. (Table 1)

Table 1 No caption

Conclusions: Infants with severe ICH and/or CPVL develop severe ROP and prethreshold disease more often than infants who do not. In the present study, there was no significant treatment effect for prenatal magnesium therapy in ameliorating severe ROP and/or prethreshold disease; however, these occurrences were categorically less frequent with magnesium treatment, and the study was underpowered to exclude the possibility of any treatment effect. Because of the close correlation between severe neonatal brain injury and ROP, further investigation of the potential neuroprotective effects of magnesium on the central nervous system is warranted.