The change of inclusion criteria meant
that a baseline rate of admission to the SCN or NICU would be 17% rather than 20% as per our original www.selleckchem.com/products/Cisplatin.html sample size calculations (based on a review of all 2011 outcome data for women with diabetes in pregnancy at the RWH). We undertook various recalculations to address this. Regarding the sample size with the altered baseline: To detect 10% absolute difference (as in the original calculation) we would need 289 per group—this would be a decrease in sample size—which none of the team considered optimal; To detect a 50% relative increase to 25.7% would need 379 per group, that is, 758 (100 more than current sample of 658)—again this is not ideal as the study is not funded for this and we did not use this difference in our original calculations; Or we could maintain current sample size (658) and describe the study power to detect a 10% absolute difference. The final option was chosen, that is, we agreed to maintain the current sample size and assume increased power to detect 10% absolute difference. Allowing for 5% loss to follow-up, the original sample size of 658 would provide 625 women at primary outcome measurement. This would detect a change in primary
outcome from 17% to 27% with a power of 85%. All the original secondary outcome comparisons described above will be maintained given the sample size has not altered. Outcome variables Primary outcome Proportion of infants admitted to SCN or NICU. Secondary outcomes Proportion of infants receiving exclusive breast milk at 3 months of age; Gestational age at birth; Proportion of infants receiving exclusive breast milk during initial hospital stay; Cost of the intervention to hospitals and to women and cost-effectiveness against breastfeeding outcomes; Women’s views and experiences; Fetal well-being associated with
expressing (assessed by CTG at initial then subsequent opportunistic CTG episodes); antenatal expression episodes, timing and volumes collected (intervention group only); time to lactogenesis II. Potential explanatory variables Reasons for SCN/NICU admissions; Hypoglycaemia treatments in maternity or SCN/NICU including glucose gel, intravenous glucose, glucagon, hydrocortisone; Length of time until three consecutive infant TBG levels GSK-3 ≥2.6 mmol/L; Maternal blood glucose levels following first three expressing episodes; Maternal morbidity that could be related to expressing, for example, premature labour. Data collection Maternal and infant Demographic data (including age, education, marital status, ethnic background, smoking) will be collected by questionnaire at recruitment, prior to randomisation. Obstetric/neonatal medical outcomes will be abstracted from the medical record following the birth by researchers blinded to group allocation. Other outcome data will be collected by telephone administered questionnaire at 1–2 and 12 weeks postpartum.