Effect of Magnesium Sulphate in mothers suffering from toxemia of pregnancy and their neonates
Abstract
Background
About 10% of all pregnancies are complicated by hypertension especially the first pregnancies of
women older than 35 years or those with multiple foetuses and this can be fatal in severe cases
due to convulsions especially when accompanied by disseminated intravascular coagulation and
multiple organ failure. Magnesium Sulphate the drug of choice for management of severe
preeclampsia and eclampsia has been shown to cross the placental barrier from maternal
circulation into the foetal blood.
Objective: The main objective was to determine the levels of serum magnesium in exposed
neonates and correlate the findings with the levels in non-exposed neonates. The specific
objectives were to determine the serum urea, electrolyte and magnesium levels achieved in
mothers treated with magnesium sulphate and to measure the serum levels in their neonates.
Methodology: A quasi-experimental study design was used and the study area was Pumwani
Maternity hospital. The test group comprised mothers diagnosed with severe eclampsia and
treated with magnesium sulphate and their neonates while the control group comprised mothers
who had preeclampsia but were treated using other drugs i.e. nifedipine and methyl dopa.
Sampling was done using simple random technique. The study consisted of a total of 54 mothers
and 54 neonates. Blood samples were obtained from both mothers and neonates and the test
group results compared to the control group. The neonates’ APGAR scores, serum urea and
electrolytes and magnesium levels of both neonates and their mothers were determined and
compared. The data obtained was analyzed using descriptive and inferential statistics.
Results: There were statistically significant differences in serum sodium (p = 0.015), urea (p =
0.043) and creatinine (p = 0.008) levels between the maternal test and control groups. Serum
sodium was higher in the control group (mean 138.4, SD 3.6 versus 135.9, SD 3.8) while
creatinine (mean 89.8 versus 71.5) and urea (mean 3.3 versus 2.6) were higher in the te
There were also significant differences between neonatal test and control groups in levels of
serum urea (p = 0.007) and chloride (p = 0.017). Urea levels were significantly higher in test
compared to control groups (mean = 4.0 versus 2.9), while chloride levels were higher in the
control group (mean = 99.4 versus 97.2). The calcium and potassium levels were elevated in the
test group but not to significant levels.
There was a positive correlation between maternal and neonatal serum magnesium levels in both
groups. The correlation was stronger in the test group (r = 0.56, p = 0.003) as compared to the
control group (r = 0.35, p = 0.087).
The mean maternal serum magnesium in the test group (mean = 2.9, SD = 0.9) was significantly
higher than the control group (mean = 2.3, SD = 0.6), p = 0.008. The mean neonatal serum
magnesium in the test group (mean = 3.0, SD = 1.0) was significantly higher than the control
group (mean = 2.3, SD = 0.6), p = 0.008.
There was a statistically significant difference between the two groups in the birth weight of the
neonates Mann Whitney test p value = 0.003 . The median birth weight in the treatment group
was 2.2 kg (IQR 1.8 to 3.0) compared to a median of 3 kg (IQR 2.3 to 3.6) in the control group.
The infant birth weight was not significantly associated with neonatal serum magnesium sulphate
levels after adjusting for treatment group. The mean serum magnesium level was 0.66 mmol/L
higher in neonates in the treatment compared to control group (p = 0.008).
Conclusion: Serum creatinine and urea levels were significantly elevated in the test group as
compared to the control group. Maternally administered magnesium sulphate during
management of severe preeclampsia and eclampsia does affect serum urea and electrolyte levels
but not all electrolytes are affected significantly