Side-effects of oral misoprostol in the third stage of labour - A randomised placebo-controlled trial

Background. Misoprostol, an inexpensive, stable, orally active prostaglandi n analogue, has been suggested for use in the prevention of postpartum haem orrhage. Potential side-effects, however, need to be quantified. Objective. To compare the rate of postpartum shivering and pyrexia followin g oral misoprostol 600 mug and placebo. Design. A double-blind placebo-controlled trial. Women in labour were rando mly allocated to receive either misoprostoi 600 mug orally or placebo after delivery. Conventional oxytocics were given immediately if blood loss was thought to be more than usual. Side-effects were recorded. Postpartum blood loss in the first hour was measured by collection in a special Rat plastic bedpan. Setting. The labour ward of an academic hospital in Johannesburg, with 7 00 0 deliveries per annum. Main outcome measures. Shivering and pyrexia. Results. The groups were well matched. Misoprostol use was associated with more shivering (44% versus 11%, relative risk (RR) 4.03, 95% confidence int erval (CI) 2.85 - 5.70), pyrexia greater than or equal to 37.8 degreesC (38 % v. 6%, RR 6.23, CI 3.89 - 9.97), 1-hour systolic blood pressure greater t han or equal to 140 mmHg (33% v. 25%, RR 1.32, CI 1.03 - 1.70), and diastol ic blood pressure greater than or equal to 90 mmHg (10.5% v. 3.0%, RR 3.44, CI 1.67 - 7.11). There were no other significant differences. The study wa s not designed to be large enough to assess a difference in blood loss grea ter than or equal to 1 000 ml (9% v. 9.7%, RR 0.93, CI 0.56 - 1.53). Possib le effects on blood loss may have been obscured by the lesser use of additi onal oxytocics in the misoprostol group (14% v. 18%, RR 0.78, CI 0.54 - 1.1 3). Conclusions. This study has shown the association of postpartum oral misopr ostol 600 mug with shivering, pyrexia and hypertension. The increased blood pressure, as for the trend towards increased abdominal pain, may be second ary to the uterotonic effect of misoprostol. Large randomised trials are ne eded to assess the effectiveness of misoprostol in the prevention of postpa rtum haemorrhage, against which the disadvantages demonstrated here can be weighed.