The gentlebirth.org website is provided courtesy of
Ronnie Falcao, LM MS, a homebirth midwife in Mountain View, CA

Effects of Mag. Sulfate on Breastfeeding

There are conflicting thoughts on whether mag. sulfate before the birth will affect breastfeeding.  Here are some relevant excerpts from the lactnet archives:
 

A compilation of related messages.
 

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Jack Newman, MD, FRCPC claims:
"There is no evidence that mag sulfate decreases the milk supply." 

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". . . there was an anecdotal report in JHL about a mom whose milk didn't come in for ten days and then came in like gang busters after prolonged treatment with Mag Sulfate . . ."

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"One of the  LCs in my area has observed that moms who were on mag are also moms with hypertension and edema with fluid in the tissue space.  She has found that milk doesn't come in well until they have diuresed.  Anyone else notice this?  I actually thought mag sulfate would stimulate milk production."

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"An article several yrs ago in Peds in Review discusses that mag sulfate can have an effect on the INFANT, creating transient hypotonia, which possibly will affect feeding ability -- potentially altering early breast stimulation - decreasing infant's ability to feed."