Table 2.
Baseline and perinatal characteristics of participants in the control and intervention groups in the NiPPeR study who provided at least one human milk sample during 12 months of lactation.
| Overall (n = 336) | p-value | ||
|---|---|---|---|
| Control | Intervention | ||
| n | 169 (50.3%) | 167 (49.7%) | |
| Adherence (%) | 89.2 (82.9–95.9) | 90.4 (82.9–96.0) | n.s. |
| Duration of supplementation (days) | 405.2 ± 105.0 | 393.4 ± 98.2 | n.s. |
| Ethnicity | |||
| Caucasian | 69 (40.8%) | 66 (39.5%) | n.s |
| Chinese | 70 (41.4%) | 69 (41.3%) | |
| South Asian | 10 (5.9%) | 10 (6.0%) | |
| Malay | 10 (5.9%) | 10 (6.0%) | |
| Other | 10 (5.9%) | 12 (7.2%) | |
| Maternal age | |||
| Age at delivery (years) | 31.9 ± 2.9 | 32.3 ± 3.2 | n.s. |
| <35 | 145 (85.8%) | 130 (77.8%) | n.s |
| ≥35 | 24 (14.2%) | 37 (22.2%) | |
| Maternal pre-pregnancy BMI status | |||
| BMI (kg/m2) | 24.4 ± 5.2 | 23.3 ± 4.4 | 0.047 |
| Underweight/ normal weight | 115 (68.0%) | 128 (76.6%) | n.s. |
| Overweight | 31 (18.3%) | 25 (15.0%) | |
| Obesity | 23 (13.6%) | 13 (7.8%) | |
| Missing | – | 1 (0.6%) | |
| Highest level of education | |||
| Bachelor’s degree or higher | 136 (80.5%) | 135 (80.8%) | n.s. |
| Lesser qualification* | 33 (19.5%) | 32 (19.2%) | |
| Household income quintile | |||
| 5 (lowest) | 4 (2.4%) | 1 (0.6%) | n.s. |
| 4 | 12 (7.1%) | 16 (9.6%) | |
| 3 | 43 (25.4%) | 43 (25.7%) | |
| 2 | 60 (35.5%) | 55 (32.9%) | |
| 1 (highest) | 44 (26.0%) | 42 (25.1%) | |
| Missing | 6 (3.6%) | 10 (6.0%) | |
| Smoking during pregnancy | |||
| None | 133 (78.7%) | 148 (88.6%) | 0.035 |
| Passive | 33 (19.5%) | 16 (9.6%) | |
| Active | 3 (1.8%) | 3 (1.8%) | |
| GDM | |||
| No GDM | 123 (72.8%) | 119 (71.3%) | n.s. |
| GDM | 41 (23.4%) | 42 (25.1%) | |
| Excluded | 5 (3.0%) | 6 (3.6%) | |
| Mode of delivery | |||
| Vaginal delivery | 124 (73.4%) | 119 (71.3%) | n.s. |
| Caesarean section | 45 (26.6%) | 48 (28.7%) | |
| Infant birth weight | |||
| Birth weight (kg) | 3.24 ± 0.54 | 3.23 ± 0.53 | n.s. |
| Appropriate for gestational age | 143 (84.6%) | 142 (85.0%) | n.s. |
| Large for gestational age | 10 (5.9%) | 6 (3.6%) | |
| Small for gestational age | 16 (9.5%) | 19 (11.4%) | |
| Infant gestational age | |||
| Gestational age (weeks) | 39.2 ± 1.6 | 39.2 ± 1.5 | n.s. |
| Preterm | 14 (8.3%) | 11 (6.6%) | n.s. |
| Term or post-term | 155 (91.7%) | 156 (93.4%) | |
| Parity | |||
| Primiparous | 113 (66.9%) | 95 (56.9%) | n.s |
| Multiparous | 56 (33.1%) | 72 (43.1%) | |
| Infant sex | |||
| Male | 75 (44.4%) | 79 (47.3%) | n.s. |
| Female | 94 (55.6%) | 88 (52.7%) | |
Data are n (%), mean ± SD, or median (Q1–Q3). p-values from independent samples t-test for continuous variables or Chi-square tests for categorical variables. Adherence to the study protocol was determined by sachet counting. Duration of supplementation calculated by counting the number of days from randomisation date to delivery date. Body mass index (BMI) status was defined as per World Health Organisation: Underweight /normal weight < 25.0 kg/m2, overweight 25.0–29.99 kg/m2, obesity ≥ 30.0 kg/m2 (54). Gestational diabetes mellitus (GDM) was defined by International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria (55). Birth weight categories were determined using the Royal College of Paediatrics and Child Health 2009 U.K.-World Health Organisation growth charts (56). Gestational age was determined using a pre-specified algorithm as previously described (57) with preterm defined as birth < 37 weeks of gestation, and term or post-term as birth at ≥ 37 weeks of gestation. *Including incomplete and complete high school qualifications, and other tertiary level qualifications below bachelors (e.g., diploma or certificate). n.s., not statistically significant at p<0.05.