Perinatal death and tocolytic magnesium sulfate

Area of Science:

• Obstetrics and Gynecology
• Neonatology
• Pharmacology

Background:

• Magnesium sulfate is commonly used as a tocolytic agent to prevent preterm birth.
• The safety and efficacy of high-dose magnesium sulfate in vulnerable fetal populations require careful evaluation.
• Previous research has not definitively established a dose-response relationship between tocolytic magnesium sulfate and perinatal outcomes.

Purpose of the Study:

• To investigate the association between high total doses of tocolytic magnesium sulfate (>48 g) and perinatal mortality.
• To determine if a dose-response relationship exists for tocolytic magnesium sulfate exposure and adverse perinatal outcomes in a specific infant weight range.

Main Methods:

• A case-control study was conducted involving fetuses and neonates weighing 700-1249 g exposed to tocolytic magnesium sulfate.
• Cases were defined as perinatal deaths, and controls were survivors of magnesium sulfate exposure.
• Multivariable logistic regression and Cochrane-Armitage trend test were used to analyze data, controlling for confounding factors.

Main Results:

• Exposure to total doses of tocolytic magnesium sulfate exceeding 48 g was significantly associated with increased perinatal mortality (adjusted OR 4.7; P =.035).
• A significant dose-response relationship was observed (P =.03), suggesting a threshold effect.
• Findings were adjusted for birth weight, gestational age, year of delivery, betamethasone receipt, maternal disease, and race.

Conclusions:

• High doses of tocolytic magnesium sulfate (>48 g) are associated with increased perinatal mortality in fetuses and neonates weighing 700-1249 g.
• The results support the hypothesis of a dose-dependent risk, with a potential threshold effect.
• These findings have implications for the clinical management of magnesium sulfate administration in high-risk pregnancies.