Abstract

Objective: To test the hypothesis that the application of intravaginal prostaglandin E₂ gel before elective caesarean section (ECS) will induce a catecholamine surge in umbilical arterial blood.

Design: Randomised, double blind, placebo controlled trial.

Setting: A regional perinatal referral centre.

Patients: Mothers booked for ECS at or above 38 weeks gestation.

Interventions: Thirty six consenting mothers were randomly allocated to receive either 2 mg intravaginal prostaglandin E₂ gel (study group; n = 18) or an equal volume of K-Y jelly as a placebo (control group; n = 18) 60 minutes before the ECS. Computer generated random numbers contained in coded, sealed envelopes were used for allocation. The obstetric and neonatal teams were blinded to the randomisation status of enrolled mothers.

Main outcome measures: Catecholamine concentrations in the umbilical arterial blood samples collected at delivery.

Results: The median (interquartile range) neonatal gestation and birth weight were 271 (269–274) days and 3605 (3072–3970) g for the study group and 271 (270–273) days and 3340 (3000–3622) g for the control group. Median (interquartile range) noradrenaline (norepinephrine) concentrations in the umbilical arterial blood were significantly higher in the study group than the control group (15.9 (9.8–28.92) v 4.6 (1.65–14.4) ng/l, p = 0.03). Adrenaline (epinephrine) concentrations did not differ significantly between the two groups (1.6 (< 0.5–3.1) v 1.4 (< 0.5–2.75) ng/l, p = 0.6). No treatment related complications occurred.

Conclusion: A labour related catecholamine surge could be simulated by intravaginal prostaglandin E₂ gel.