Background: Obstetric anaesthesia has been associated with concern for the inhalation of gastric contents for many years, justifying fasting during labour. However, many anaesthesiologists and obstetricians now allow fluid intake during labour.
Objective(s): We hypothesised that allowing oral fluid intake during labour is not associated with increased gastric contents. We used ultrasound assessment of gastric contents to evaluate this hypothesis.
Design: A randomised, single-blind and intention-to-treat noninferiority trial comparing antral area measured by ultrasound in fasting parturients and in those who were allowed to drink fluid for 90 min after randomisation.
Setting: Tenon University Hospital, Assistance Publique Hôpitaux de Paris, Paris, France.
Patients: Pregnant women, aged from 18 to 40 years and from week 36 of an uncomplicated singleton gestation, were randomised into a fasting group and a fluid intake group after admission to the delivery room. Of the 184 patients screened, data from 125 were analysed: fasting group (62), fluid intake group (63).
Intervention: Women in the fluid intake group were allowed to drink up to 400 ml of apple juice for 90 min after randomisation.
Main outcome measure: We compared the percentage of women with an 'empty stomach' between the two groups: empty stomach was defined as an antral cross-sectional area (CSA) less than 300 mm assessed in a semirecumbent position with a 45-degree head-up tilt.
Results: At full cervical dilatation an antral CSA less than 300 mm was measured in 76 and 79% of the parturients in the fasting group and the fluid intake groups respectively (P = 0.633).
Conclusion: The current study reveals that the percentage of pregnant women with an 'empty stomach', defined by an antral CSA less than 300 mm in a semirecumbent position with a 45-degree head-up tilt, was comparable at full cervical dilation among those who remained nil by mouth and those allowed to drink up to 400 ml for 90 min after their randomisation.
Trial registration: Clinicaltrials.gov identifier: NCT02362815.