**3. Results**

#### *3.1. Characteristics of the Study Cohort*

Table 1 shows the characteristics of mothers disaggregated by ethnic group. The primary caregiver was defined as the person who spent the most time with the study infant. Irish mothers were younger on average than non-Irish (31.7 years with SD 5.3 compared to 30.9 with SD 5.4). Of those mothers with an Irish ethnic background, 49.5% initiated breastfeeding compared to 88.1% of those mothers with a non-Irish ethnic background. The mean duration of any breastfeeding for those that breastfed at all was 71.1 days (SD 66.4) for Irish mothers compared to 95.8 days (SD 69.2) for non-Irish. A higher percentage of mothers with an Irish ethnic background (15.5% *vs*. 7.6%) introduced complimentary foods early.
