Antenatal Magnesium Sulfate and Preeclampsia Differentially Affect Neonatal Cerebral Oxygenation

Abstract

Introduction: Magnesium sulfate (MgSO 4) is frequently administered for maternal and fetal neuroprotection in preeclampsia (PE) and imminent preterm birth, respectively. Objective: To assess whether MgSO 4 affects neonatal cerebral oxygenation, blood flow, and cerebral autoregulation (CAR) during the first postnatal days independently from PE. Methods: 148 neonates < 32 weeks gestational age were included. Cerebral fractional tissue oxygen extraction (cFTOE) was extracted from a daily 2-h period, during which peak systolic blood flow velocity (PSV) and resistance index (RI) of the pericallosal artery were obtained. The percent time of impaired CAR (correlation coefficient between mean arterial blood pressure and cerebral oxygen saturation > 0.5) was determined. Linear mixed models were applied. Results: MgSO 4 exposure was recorded in 77 neonates. Twenty-nine neonates were born following PE. MgSO 4 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. MgSO 4 did not alter CAR. Conclusions: In contrast to fetal brain sparing in PE, MgSO 4 seems to lower cFTOE by lowering cerebral oxygen demands in preterm neonates without affecting the cerebrovasculature.

The Role of MgSO4 in Reducing the Risk of Severe Preeclampsia (PEB) Patients Becoming Eclampsia

“…brain in preterm labor. MgSO4 also reduces the risk of neontal cerebral palsy, its benefits regarding periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), and mortality are controversial (Richter et al, 2020). MgSO4 is given intamuscular (IM) or intravenous (IV).…”

Brain Vascular Dysfunction in Mothers and Their Children Exposed to Preeclampsia

“…Furthermore, this tendency disappeared after multivariate analysis adjusting for confounders, such as fetal brain sparing. 153 These results suggest that impaired autoregulation might extend after birth in children born from women with preeclampsia. However, many confounding factors, including preterm birth, use of hypertensive drugs, intrauterine growth restriction, and magnesium sulfate, among others, make this assumption challenging to sustain.…”

Reduced Brain Cortex Angiogenesis in the Offspring of the Preeclampsia-Like Syndrome

“…64 Despite that, epidemiological data show that brains that have been spared are nevertheless compromised and associated with elevated risks for brain-associated adverse outcomes, including compromised cognitive function. Thus, brain angiogenesis alterations likely start during the intrauterine period and persist immediately (days) after birth, 65 constituting a critical developmental window. Notwithstanding these findings, we wish to make clear that fetal brain blood flow alterations intrauterine or immediately after birth are not exclusive to preeclampsia because they are also observed in fetal growth restriction, postterm pregnancies, previous pregnancy loss, and women with hypertension, diabetes, or other maternal pathology.…”