Table 1. Maternal and infant characteristics of the study population at 6 months.
| Not breastfed (n = 35) | Breastfed (n = 223) | |
|---|---|---|
| Maternal characteristics (n = 258) | ||
| Age (Mean ± SD; years) | 32 (3.6) | 32 (3.8) |
| Educational level (n; %) | ||
| Lower | 24 (69%) | 71 (32%) |
| Higher | 11 (31%) | 152 (68%)* |
| Net household income per month (n; %) | ||
| < € 2400 | 2 (7%) | 23 (11%) |
| ≥ € 2400 | 29 (93%) | 178 (89%) |
| Smoking continued during pregnancy (n; %) | 4 (14%) | 21 (13%) |
| Alcohol use continued during pregnancy (n; %) | 8 (29%) | 55 (35%) |
| Body Mass Index before pregnancy (Mean ± SD; kg/m2) | 23 (3) | 23 (4) |
| Fever in third trimester of pregnancy (n; %) | 3 (9) | 14 (6%) |
| Maternal atopy (eczema, allergy HDM, hay-fever)(n; %) | 8 (25%) | 72 (35%) |
| Paternal atopy (eczema, allergy HDM, hay-fever) (n; %) | 8 (28%) | 55 (28%) |
| Family history of asthma / atopy (n; %) | 13 (37%) | 107 (49%) |
| Any reported autoimmune disease (diabetes mellitus, SLE, arthritis, MS, thyroid disorder, or celiac disease) (n; %) | 0 (0%) | 5 (0.02%) |
| Mode of delivery (n; %) | ||
| Vaginal | 21 (64%) | 129 (61%) |
| Forceps or vacuum assisted | 5 (15%) | 44 (20%) |
| Caesarian section | 7 (21%) | 40 (19%) |
| Premature rupture of membranes (n; %) | 3 (9%) | 6 (3%) |
| Infant characteristics (n = 258) | ||
| Males (n; %) | 19 (54%) | 113 (51%) |
| Gestational age (Mean ± SD; weeks) | 39.4 (2.4) | 40.0 (1.7) |
| Preterm birth (<37 weeks) (n; %) | 2 (6%) | 11 (5%) |
| Birth weight (Mean ± SD; grams) | 3439 (632) | 3504 (524) |
| Apgar score at 5 min <7 (n; %) | 0 (0%) | 3 (1%) |
| Birth season (n; %) | ||
| Winter (dec-jan-feb) | 5 (14%) | 36 (16%) |
| Spring (mar-apr-may) | 10 (29%) | 81 (36%) |
| Summer (jun-jul-aug) | 11 (31%) | 62 (28%) |
| Autumn (sept-oct-nov) | 9 (26%) | 44 (20%) |
| Siblings ≥1 (n; %) | 4 (11%) | 26 (12%) |
| Day-care >16 hours /week (n; %) | 5 (33%) | 77 (46%) |
| Fever in first 6 months (n; %) | 12 (60%) | 121 (62%) |
| Age at focus visit (Median ± range; months) | 6.6 (6.2–8.2) | 6.2 (5.2–7.9)* |
Values are means (SD), absolute numbers (percentages) or #medians (90% range).
*Significantly different between groups.
Data were missing on: Household income (n = 26) Smoking during pregnancy (n = 72), Alcohol during pregnancy (n = 72) BMI before pregnancy (n = 37), Fever in third trimester (n = 9) Mode of delivery (n = 12) Maternal atopy (n = 22) Paternal atopy (n = 29), Family history of asthma or atopy (n = 3) Mode of delivery (n = 12), maternal reported autoimmune disease (n = 29), maternal reported any other chronic condition (n = 31), premature rupture of membranes (n = 5), Apgar (n = 4), Day-care (n = 42), weight at focus visit (n = 1), fever in first 6 months (n = 42). Any reported autoimmune disease included thyroid disease (n = 4) and elevated anti-tTG level during pregnancy (n = 1).