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Magnesium oxide Pregnancy and Breastfeeding Warnings

Magnesium oxide is also known as: Mag-200, Mag-Caps, Mag-Ox, Mag-Ox 400, Mag-Oxide, MagGel, Phillips' Cramp-free, Uro-Mag

Medically reviewed on Apr 28, 2017

Magnesium oxide Pregnancy Warnings

Safety has not been established during pregnancy.

AU TGA pregnancy category: Exempt
US FDA pregnancy category: Not assigned

Comments:
-Magnesium needs are increased during pregnancy.
-Oral magnesium supplements do not appear to help with leg cramps during pregnancy.
-The National Institute for Health and Care Excellence (NICE) does not recommend using magnesium solely for prevention of hypertensive disorders in pregnancy.

There are no controlled data in human pregnancy. Supplemental magnesium does not appear to effect the incidence of preterm birth or perinatal mortality. Magnesium supplementation in gestational diabetes may lower the incidence of newborn hyperbilirubinemia and hospitalization.

AU Exempt: Medications exempted from pregnancy classification are not absolutely safe for use in pregnancy in all circumstances. Some exempted medicines, for example the complementary medicine, St John's Wort, may interact with other medicines and induce unexpected adverse effects in the mother and/or fetus.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

See references

Magnesium oxide Breastfeeding Warnings

Safety has not been established.

Excreted into human milk: Yes


Comments:
-Small amounts of magnesium are excreted in breast milk.
-50 to 90% of magnesium in breast milk is absorbed.
-Urinary excretion of magnesium decreases and bone resorption increases during lactation.
-Maternal magnesium supplementation is not expected to affect the infant's serum magnesium levels.

See references

References for pregnancy information

  1. Australian Government, Department of Health and Ageing, National Health and Medical Research Council "Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes Available from: URL: https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/n35.pdf." ([2006]):
  2. Asemi Z, Karamali M, Jamilian M, et.al "Magnesium supplementation affects metabolic status and pregnancy outcomes in gestational diabetes: a randomized, double-blind, placebo-controlled trial." Am J Clin Nutr 102 (2015): 222-9
  3. Han S, Crowther CA, Moore V "Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour. Cochrane Database of Systematic Reviews. Available from: URL: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000940.pub3/epdf." ([2013]):
  4. Zhou K, West HM, Zhang J, Xu L, Li W "Interventions for leg cramps in pregnancy. Cochrane Database of Systematic Reviews. Available from: URL: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010655.pub2/full." ([2015]):
  5. National Institute for Health and Care Excellence "NICE Guidance: Do Not Do Recommendation, Do not recommend magnesium solely with the aim of preventing hypertensive disorders during pregnancy. Available from: URL: https://www.nice.org.uk/donotdo/do-not-recommend-magnesium-solely-with-the-aim-of-preventin" ([2015, June]):

References for breastfeeding information

  1. United States National Library of Medicine "Toxnet. Toxicology Data Network. Available from: URL: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT." ([cited 2013 -]):
  2. Australian Government, Department of Health and Ageing, National Health and Medical Research Council "Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes Available from: URL: https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/n35.pdf." ([2006]):
  3. Nice FJ, Snyder JL, Kotansky BC "Breastfeeding and over-the-counter medications." J Hum Lact 16 (2000): 319-31

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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