Lipid peroxidation in cord blood: a randomised sequential pairs study of prophylactic saline amnioinfusion for intrapartum oligohydramnios.

OBJECTIVE

To determine the efficacy of prophylactic intrapartum amnioinfusion in reducing cord arterial lipid peroxide levels in cases of intrapartum oligohydramnios.

DESIGN

Sequential randomised pairs trial.

SETTING

Delivery suite of a teaching hospital, the Chinese University of Hong Kong.

POPULATION

Women with singleton, term pregnancy, cephalic presentation, clear amniotic fluid and an amniotic fluid index < or = 5 cm, with a normal intrapartum fetal heart rate tracing within 30 minutes of amniotomy.

METHODS

Selected patients were randomised either for prophylactic saline amnioinfusion or as control cases. Cord arterial lipid peroxide concentrations and acid base balance were determined at delivery.

MAIN OUTCOME MEASURES

Operative intervention for fetal distress, cord arterial malondialdehyde and organic hydroperoxide levels, pH and base excess.

RESULTS

Amnioinfusion was associated with significant reductions in the incidence of operative delivery for fetal distress and in lipid peroxide levels, an increase in base excess, but no significant alteration in pH.

CONCLUSIONS

Oligohydramnios in labour is associated with high levels of lipid peroxidation, reflecting cellular damage by release of free radicals following hypoxia reperfusion. Prophylactic intrapartum saline amnioinfusion is an effective technique for the reduction of lipid peroxidation and of the incidence of operative intervention for fetal distress but has no significant effect on overall operative delivery rates.