MATERNAL RECEIPT OF MAGNESIUM-SULFATE DOES NOT SEEM TO REDUCE THE RISK OF NEONATAL WHITE-MATTER DAMAGE

Objective. To investigate whether in to magnesium sulfate is associate d with a lower incidence of cranial ultrasonographic abnormalities tha t predict cerebral palsy in infants who weigh less than 1501 g at birt h. Design. For a prospective study of the antecedents of cranial ultra sonographic abnormalities, we enrolled infants who weighed 500 to 1500 g when born at five institutions. Data were collected by interview of the mothers and review of medical records. Protocol cranial ultrasono grams were obtained as close as possible to postnatal days 1, 7, and 2 1. Abnormality on cranial ultrasound scans was determined by a consens us committee of three sonologists. Results. Of the 1518 infants for wh om we knew whether the mothers received magnesium sulfate, the first p rotocol cranial ultrasound scan was available for 1409 infants, the se cond for 1274 infants, and the third for 1050 infants. Forty-five perc ent of infants were exposed to magnesium sulfate before delivery. The major correlates of magnesium sulfate exposure were receipt of antenat al corticosteriods and a diagnosis of preeclampsia and/or pregnancy-in duced hypertension. Maternal magnesium receipt was not associated with a reduced incidence of hypoechoic or hyperechoic images of white matt er parenchyma, intraventricular hemorrhage, or ventriculomegaly, even when the sample was stratified by each of six potential confounders. W hen adjustment was made for gestational age, a measure of birth weight for gestational age, antenatal corticosteroid exposure, preeclampsia and pregnancy-induced hypertension, route of delivery, and the occurre nce of any labor, the risk ratios for each cranial ultrasonographic ab normality associated with magnesium sulfate exposure hovered close to 1. Conclusion. Maternal receipt of magnesium sulfate does not seem to be associated with an appreciably reduced risk of cranial ultrasonogra phically defined neonatal white matter damage, intraventricular hemorr hage, or ventriculomegaly.