Carbohydrate solution intake during labour just before the start of the second stage: a double-blind study on metabolic effects and clinical outcome

Abstract

Objective: To study the effects of oral carbohydrate ingestion on clinical outcome and on maternal and fetal metabolism.

Design: Prospective, double-blind, randomised study.

Setting: Leyenburg Hospital, The Hague, The Netherlands.

Population: Two hundred and two nulliparous women.

Methods: In labour, at 8 to 10 cm of cervical dilatation, the women were asked to drink a solution containing either 25 g carbohydrates or placebo. In a subgroup of 28 women, metabolic parameters were measured.

Main outcome measures: Number of instrumental deliveries, fetal and maternal glucose, free fatty acids, lactate, pH, Pco2, base excess/deficit and beta-hydroxybutyrate.

Results: Drinking a carbohydrate-enriched solution just before starting the second stage of labour did not reduce instrumental delivery rate (RR 1.1, 95% CI 0.9-1.3). Caesarean section rate was lower in the carbohydrate group, but the difference did not reach statistical significance (1% vs 7%, RR 0.2, 95% CI 0.02-1.2). In the carbohydrate group, maternal free fatty acids decreased and the lactate increased. In the umbilical cord there was a positive venous-arterial lactate difference in the carbohydrate group and a negative one in the placebo group, but the differences in pH and base deficit were comparable.

Conclusion: Intake of carbohydrates just before the second stage does not reduce instrumental delivery rate. The venous-arterial difference in the umbilical cord suggested lactate transport to the fetal circulation but did not result in fetal acidaemia.