Probiotic group (n=373) | Placebo group (n=362) | |

Perinatal characteristics | ||

Multiple births, N (%) | 140 (37.5) | 127 (35.1) |

Antenatal steroids (any), N (%) | 342 (91.7) | 334 (92.3) |

Maternal antibiotics, N (%) | 183 (49.1) | 173 (47.8) |

Chorioamnionitis, N (%) | 28 (7.5) | 34 (9.4) |

Caesarean section, N (%) | 242 (64.9) | 253 (69.9) |

Gestational age, mean (SD) weeks | 27.6 (2.0) | 27.6 (1.9) |

<28 weeks, N (%) | 165 (44.2) | 171 (47.2) |

Birth weight, mean (SD) g | 1042 (267) | 1027 (261) |

<1000 g, N (%) | 177 (47.5) | 170 (47.0) |

Birthweight z-score*, mean (SD) | −0.3 (1.1) | −0.4 (1.1) |

Male, N (%) | 193 (51.7) | 207 (57.2) |

5 min Apgar score, median (IQR) | 8 (7–9) n=371 | 8 (7–9) n=358 |

Age at enrolment into original RCT, mean (SD) days | 2.0 (0.9) | 2.1 (0.9) |

Age commenced study powder, median (IQR) days^{†}
| 5.0 (4.0–7.0) n=371 | 5.0 (4.0–7.0) n=352 |

Neonatal characteristics | ||

Any EBM, n (%) | 356 (95.4) | 355 (98.1) |

NEC (Bell Stage 2 or greater), n (%) | 9 (2.4) | 20 (5.5) |

IVH Grade 3 or 4 or cystic PVL, n (%) | 17 (4.6) | 10 (2.8) |

At least one episode of definite late-onset sepsis, n (%) | 57 (15.3) | 55 (15.2) |

BPD at 36 weeks, n (%) | 117 (33.7) n=347 | 110 (32.7) n=336 |

ROP ≥grade 3, n (%) | 18 (4.8) | 17 (4.7) |

*Z-score was calculated using the LMS British preterm growth data.

†Some babies died prior to commencing study powder (13 probiotics, 15 placebo).

BPD, bronchpulmonary dysplasia; EBM, expressed breast milk; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PVL, periventricular leukomalacia; RCT, randomised controlled trial; ROP, retinopathy of prematurity.