Can magnesium supplements delay labor and cause a stuffy nose?

[Jaimee]

I've been taking quite a bit of Natural Calm (magnesium citrate) to prevent leg cramps for the last 5 weeks or so.  I am wondering if it could suppress contractions and delay labor?  I know that large doses of magnesium sulfate are often given to stop pre-term labor... does anyone know if smaller doses could delay full term labor?

Also, I see that a side effect of magnesium sulfate is stuffy nose.  My nose has been clogged for almost two weeks now.  Could there be any connection to the Natural Calm?

[dogmom327]

I was taking a bunch of magnesium in the few weeks before DS was born and I had a really nice easy but longer (24h) labor (spontaneous at 38w). With DD, no magnesium and had an 18 hour very painful labor (also spontaneous at 38w). I've always wondered if the magnesium made a difference.

[Jaimee]

Turned out the stuffy nose was a sinus infection that just too a loooong time to manifest fully.  As for labor, hard to say.  I stopped taking it and I did feel an increase in BH, but my mw assured me that magnesium was not going to stop labor from starting once my body was truly ready.  In the end, I went to 40w5d and had a long, difficult 24 hour labor.  This was caused by baby's head being slightly cocked, pinching the cervix, and not allowing me to dilate fully.  My mw ended up moving and stretching the cervix during several contractions to line baby up properly.  Side note, I also had a leg cramp that kept returning while I was in transition, downed a glass of Natural Calm, and it went away immediately.  So I think the moral is, Natural Calm can be helpful and is not going to hinder labor, but baby's position certainly can!