The Effect of Magnesium Sulfate Therapy on Bleeding Time in Women with Threatened Preterm Labor

Magnesium sulfate is widely used in obstetrics and is drug of choice in two important complications of pregnancy, preeclampsia and preterm labor. The antagonistic effects of magnesium sulfate on calcium ion and on platelet aggregation may lead to changes in bleeding time. This study was conducted to evaluate the effect of magnesium sulfate on bleeding time in women with threatened preterm labor. A group of 40 patients with signs of preterm labor were treated with magnesium sulfate (4 grams in 200 ml D.W.5% in 20 minutes followed by maintenance dose of 2 grams per hour infusion) and template bleeding time (with IVY method), platelet count and mean arterial pressure were obtained before and 2 hours after magnesium sulfate infusion. The data were analyzed using paired t-test. The mean bleeding time before and after treatment were 161.1 + 50.6 and 169 + 61.8 seconds respectively and the mean platelet count was 179,925 and 185,250 respectively. The mean arterial pressure was 86.9 + 9 mmHg before treatment compared to 81.9 + 8.3 mmHg after treatment. According to the data presented in this study, there was no significant difference in bleeding time and platelet count before and after treatment with magnesium sulfate whereas the mean arterial pressure was significantly different (p<0.001) before and after treatment with magnesium sulfate