Is the prophylactic administration of magnesium sulphate in women with pre-eclampsia indicated prior to labour?

Objective To determine whether prophylactic magnesium sulphate is necessary to prevent eclampsia and associated complications among women with pre-ecl ampsia prior to labour. Design Case series. Setting Tertiary referral centre. Population Three hundred and eighteen women with pre-eclampsia (blood press ure greater than or equal to 140/90 mmHg and greater than or equal to 2+ pr oteinuria) who were not in labour or for planned induction thereof and had not received magnesium sulphate during transfer. Methods Clinical evaluation of the pregnant women with careful blood pressu re control. Magnesium sulphate was withheld even in the presence of imminen t eclampsia. During labour, the option of magnesium sulphate prophylaxis wa s left to the clinician, but magnesium sulphate was administered in cases o f eclampsia. Main outcome measures Eclampsia and related complications. Results Five women (1.5%) developed eclampsia, although none developed rela ted complications. Women presented at an early gestational age (mean 30 wee ks), with high blood pressure, often suffering from headaches. Twenty pregn ancies were terminated prior to viability, of which half were terminated fo r maternal reasons. Ten intrauterine deaths occurred. Most often fetal dist ress (38.6%) initiated the delivery process, which was mainly by caesarean section (68.5%). With the exception of epigastric discomfort, symptoms and signs of imminent eclampsia decreased after admission. Blood pressure value s were significantly lower at delivery although biochemistry results deteri orated from admission to delivery. Conclusion In women with pre-eclampsia prior to labour, where blood pressur e control was carefully applied but magnesium sulphate not given, the eclam psia rate was low and eclampsia did not appear to worsen the existing progn osis for mother or fetus.