Magnesium supplementation and perinatal hypoxia: outcome of a parallel group randomised trial in pregnancy.
OBJECTIVE
To determine the effects of magnesium supplementation in pregnancy on the incidence of hypoxic-ischaemic encephalopathy (HIE).


METHODS
A randomised double-blind placebo-controlled study.


METHODS
A Midwife Obstetric Unit and its two referral hospitals in Cape Town, South Africa.


METHODS
A group of 4494 black pregnant women of low socio-economic status.


METHODS
Mothers, from the time of booking until delivery, were randomised to receive two identical tablets daily, containing either 128 mg slow-release magnesium stearate or lactose sugar.


METHODS
Primary: The incidence of HIE. Secondary: The incidence of fetal heart rate decelerations, term Stillbirths, Low Apgar Scores, Meconium Aspiration Pneumonia.


RESULTS
The incidence of HIE (0.9%) was considerably less than anticipated (2%). There were 22 infants in the placebo group and 15 infants in the supplemented group (P = 0.279). The difference was not significant. Secondary outcomes such as late fetal heart rate decelerations (P = 0.002) and term stillbirths (P = 0.016) were reduced significantly in the supplemented group, but this finding needs further substantiation.


CONCLUSIONS
Magnesium supplementation did not reduce the incidence of HIE significantly, probably because the study was underpowered and compliance was relatively poor.
Harrison
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School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa. costello@netactive.co.za
Fawcus
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Jordaan
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E
D000293:Adolescent; D000328:Adult; D001034:Apgar Score; D001145:Arrhythmias, Cardiac / Q000209:etiology; D003692:Delayed-Action Preparations; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005318:Fetal Heart; D006801:Humans; D020925:Hypoxia-Ischemia, Brain; D007231:Infant, Newborn; D008471:Meconium Aspiration Syndrome / Q000209:etiology; D008875:Middle Aged; D010865:Pilot Projects; D011247:Pregnancy; D011256:Pregnancy Outcome; D013229:Stearic Acids / Q000008:administration & dosage*; D050497:Stillbirth
D003692:Delayed-Action Preparations; D013229:Stearic Acids; C031183:stearic acid