Magnesium supplementation in pregnancy.
BACKGROUND
Many women, especially those from disadvantaged backgrounds, have intakes of magnesium below recommended levels. Magnesium supplementation during pregnancy may be able to reduce fetal growth retardation and pre-eclampsia, and increase birthweight.


OBJECTIVE
The objective of this review was to assess the effects of magnesium supplementation during pregnancy on maternal, neonatal and paediatric outcomes.


METHODS
We searched the Cochrane Pregnancy and Childbirth Group trials register.


METHODS
Randomised and quasi-randomised trials of dietary magnesium supplementation during pregnancy.


METHODS
Suitability for inclusion and methodological quality were separately assessed by each reviewer. Data were independently extracted by two reviewers.


RESULTS
Six trials involving 2637 women were included. Only one of these trials was judged to be of high quality. Compared with placebo, oral magnesium treatment from before the 25th week of gestation was associated with a lower incidence of preterm birth (odds ratio 0.71, 95% confidence interval 0.52 to 0.95). There was also less maternal hospitalisation during pregnancy, fewer cases of antepartum haemorrhage, a lower incidence of low birthweight and small for gestational age infants. Poor quality trials are likely to have resulted in a bias favouring magnesium supplementation.


CONCLUSIONS
There is not enough high quality evidence to show that dietary magnesium supplementation during pregnancy is beneficial.
Makrides
M
M
Women's and Children's Hospital, Obstetrics and Gynaecology, University of Adelaide, 72 King William Road, North Adelaide, SA, Australia, 5006. mmakrides@medicine.adelaide.edu.au
Crowther
C A
CA
D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008274:Magnesium; D011247:Pregnancy
D008274:Magnesium