Supplementary Material for: Antenatal Magnesium Sulfate and Preeclampsia Differentially Affect Neonatal Cerebral Oxygenation

Introduction: Magnesium sulfate (MgSO4) is frequently administered for maternal and fetal neuroprotection in preeclampsia (PE) and imminent preterm birth, respectively. Objective: To assess whether MgSO4 affects neonatal cerebral oxygenation, blood flow, and cerebral autoregulation (CAR) during the first postnatal days independently from PE. Methods: 148 neonates 0.5) was determined. Linear mixed models were applied. Results: MgSO4 exposure was recorded in 77 neonates. Twenty-nine neonates were born following PE. MgSO4 independently lowered cFTOE (B: –0.026, 95% CI: –0.050 to 0.002, p < 0.05) but did not affect PSV and RI. PE was associated with a lower cFTOE (B: –0.041, 95% CI: –0.067 to –0.015, p < 0.05) and a tendency towards both lower PSV (B: –4.285, 95% CI: –9.067 to 0.497, p < 0.1) and more impaired CAR (B: 4.042, 95% CI: –0.028 to 8.112, p < 0.1), which seemed to be strongly mediated by fetal brain sparing. MgSO4 did not alter CAR. Conclusions: In contrast to fetal brain sparing in PE, MgSO4 seems to lower cFTOE by lowering cerebral oxygen demands in preterm neonates without affecting the cerebrovasculature