Objectives Probiotics are live microorganisms which may confer health benefits on the host. Recent studies have demonstrated various beneficial effects of probiotics in pregnancy among healthy women.¹ The aim of this study was to investigate the effects of a probiotic capsule on maternal fasting glucose and pregnancy outcome in obese pregnant women.

Methods This double-blind randomised controlled trial recruited pregnant women with a body mass index of 30.0–39.9kg/m². Women were randomised to either a daily probiotic (Lactobacillus salivarius UCC118) or placebo capsule from 24 to 28 week’s gestation. The primary outcome was a reduction in fasting glucose from pre to post-intervention and secondary outcomes were incidence of gestational diabetes and neonatal anthropometry. A sample size of 100 was required to detect a reduction in fasting glucose of 0.4 mmol/l with at least 80% power.

Results Of 138 participants, 28 were excluded from analyses due to antibiotic usage and poor capsule compliance, leaving 110 women for final analysis. BMI was the only factor that differed between the intervention groups at baseline (32.9 ± 2.6 probiotic vs 34.0 ± 2.7kg/m² placebo, p = 0.044). Adjusting for BMI, no difference was noted in fasting glucose from pre- to post-intervention (-0.07 ± 0.41 probiotic vs –0.11 ± 0.27 mmol/l placebo, p = 0.295). There was also no difference in birth weight centile, incidence of gestational diabetes or other adverse pregnancy outcomes between the groups.

Conclusion While previous studies of probiotics in healthy pregnant women showed some beneficial glycaemic effect, this randomised trial demonstrated no impact on fasting glucose or on obstetric outcomes in obese pregnancy.

Reference 1Lindsay KL, Walsh CA, Brennan L, McAuliffe FM. Probitoics in pregnancy and maternal outcomes: A systematic review. J Mat Fet Neonat Med2013;26:772–8