Magnesium sulfate is used for seizure prophylaxis in pregnancies complicated by preeclampsia. There is debate as to how long to continue this therapy after delivery of the pregnancy. Different schemes have been offered to shorten the exposure to magnesium sulfate after delivery, with little data. We seek to investigate the effect of shortened magnesium sulfate therapy on the post-partum recovery phase of mild preeclampsia. Our hypothesis was that shortened therapy (12 hours versus the traditional 24 hours post-partum) has no effect on disease course, and will result in significantly shorter exposure to magnesium sulfate.

The study has been completed at this time.

Consenting women with suspected mild preeclampsia (new onset/exacerbated hypertension with proteinuria) were randomly assigned 12 (12-hour) or 24-hours (24-hour) of postpartum MgSO4. Treatment was continued beyond the initially assigned time period for new findings of severe preeclampsia. Clinical and laboratory data were collected. Analysis was by intent to treat, utilizing Fisher's exact, chi-square, and Student's t-tests where appropriate

Inclusion Criteria:

• Women with suspected mild preeclampsia diagnosed antepartum, intrapartum, or post-partum were eligible for inclusion after delivery at term (≥ 34 weeks' gestational age).

Exclusion Criteria:

• Inability to give informed consent, preterm delivery, severe preeclampsia