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Magnesium chloride Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on Jun 20, 2022.

Magnesium chloride is also known as: Chloromag, Mag-SR

Magnesium chloride Pregnancy Warnings

The intravenous drug should be used during pregnancy only if clearly needed.

AU TGA pregnancy category: Exempt
US FDA pregnancy category: C

-There is no data on use in pregnant women to know this drugs risks, including the risk of fetal harm or reproductive effects.
-According to some authorities magnesium chloride should not be administered within 2 hours prior to delivery because of a risk of hypermagnesemia stimulated respiratory depression in the neonate.
-The US Recommended Dietary Allowance of magnesium during pregnancy is increased compared to non-pregnant women.

Animal studies have not been conducted. Magnesium readily crosses the placenta with fetal concentrations similar to maternal concentrations. There are no controlled data in human pregnancy. Bony abnormalities and congenital rickets have been reported in neonates after prolonged administration (4 to 13 weeks) of parenteral magnesium to the mothers. The background birth defect and miscarriage risk for the indicated population is not known. In the US general population, the estimated major birth defect risk is 2 to 4% and the miscarriage risk is 15 to 20%.

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 chloride Breastfeeding Warnings

Intravenous use is not recommended.

Excreted into human milk: Yes

-The breast milk concentration is approximately double the maternal serum concentration.
-The US Recommended Dietary Allowance of magnesium during lactation is the same as for non-lactating women.

See references

References for pregnancy information

  1. Cerner Multum, Inc. "Australian Product Information." O 0
  2. TGA. Therapeutic Goods Administration. Australian Drug Evaluation Committee "Prescribing medicines in pregnancy: an Australian categorisation of risk of drug use in pregnancy." (2010):
  3. "Product Information. Magnesium Chloride, Injectable (magnesium chloride)." Mylan Pharmaceuticals Inc (2018):
  4. National Institutes of Health "Magnesium: Fact sheet for Health Professionals. 371109" (2018):

References for breastfeeding information

  1. Cerner Multum, Inc. "Australian Product Information." O 0
  2. National Institutes of Health "Magnesium: Fact sheet for Health Professionals. 371109" (2018):

Further information

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