Table 1.
Background characteristics of study participants. IAP indicates intrapartum antibiotics prophylaxis. Y = Yes, N = No.
| Antibiotics: Mother Y/N Infant Y/N | Control | IAP | Postnatal | IAP + Postnatal | P valued |
|---|---|---|---|---|---|
| NN | YN | NY | YY | ||
| N = 47 | N = 44 | N = 29 | N = 29 | ||
| Birth weight (g) mean (SD) | 3448 (434) | 3589 (517) | 3627 (474) | 3484 (350) | 0.28 |
| Gestational age (d) mean (SD) | 279 (8) | 279 (8) | 283 (7) | 279 (11) | 0.21 |
| Girls N (%) | 23 (49) | 15 (34) | 16 (55) | 17 (59) | 0.15 |
| Apgar 10 min N (%) | |||||
| 4–7 | 0 (0) | 0 (0) | 7 (25) | 7 (24) | ND5 |
| 8–10 | 47 (100) | 44 (100) | 21 (75)a | 22 (76) | ND |
| L. reuteri during antibiotics | 0 (0) | 0 (0) | 29 (100) | 29 (100) | ND |
| Exclusive breastfeeding (months) | 4.6 (1.0) | 3.9 (1.3) | 5.0 (1.1) | 4.3 (1.2) | 0.06 |
| Maternal age mean (SD) | 29.7 (4.1) | 28.5 (5.1) | 28.5 (5.2) | 29.9 (5.6) | 0.47 |
| Maternal weight (kg) mean (SD)b | 62.6 (10.7) | 66.0 (14.9) | 62.5 (13.7) | 68.4 (12.1) | 0.19 |
| Maternal BMIb | 23.2 (4.2) | 24.0 (4.9) | 22.9 (4.4) | 25.7 (5.0) | 0.07 |
| Maternal smoking N (%) | 1 (2) | 4 (9) | 2 (7) | 2 (7) | 0.56 |
| Maternal chronic medical conditions N (%) | 0.15 | ||||
| Total | 7 (15) | 6 (14) | 7 (24) | 9 (31) | 0.15 |
| Asthma | 5 (11) | 2 (5) | 2 (7) | 1 (3) | |
| Atopic eczema | 0 (0) | 0 (0) | 1 (3) | 1 (3) | |
| Hyperthyreosis | 0 (0) | 1 (2) | 0 (0) | 1 (3) | |
| Hypothyreosis | 1 (2) | 1 (2) | 2 (7) | 4 (14) | |
| IBD | 0 (0) | 2 (4) | 0 (0) | 1 (3) | |
| Epilepsy | 1 (2) | 0 (0) | 0 (0) | 0 (0) | |
| Maternal proton pump inhibitor | 0 (0) | 0 (0) | 2 (7) | 0 (0) | 0.32 |
| Maternal iron supplementation | 13 (28) | 10 (23) | 22 (76) | 18 (62) | 0.52 |
| Maternal D-vitamin supplementation | 13 (28) | 14 (32) | 3 (10) | 10 (34) | 0.14 |
| Maternal diet N (%) | |||||
| Vegetarian | 2 (4) | 1 (2) | 0 (0) | 1 (3) | 0.73 |
| Probiotics | 10 (21) | 14 (32) | 2 (7) | 8 (28) | 0.07 |
| Antibiotics during pregnancy N (%) | 10 (21) | 12 (27) | 4 (13) | 10 (34) | 0.92 |
| Intrapartum antibiotics (IAP) N (%) | |||||
| Penicillin G | 38 (86) | 17 (59) | ND | ||
| Cefuroxime | 4 (9) | 5 (17) | ND | ||
| Clindamycin | 2 (5) | 4 (14) | ND | ||
| Penicillin + Cefuroxime | 0 (0) | 3 (10) | ND | ||
| No. of IAP antibiotic doses Mean (range) | 1.9 (1 to 4) | 1.9 (1 to 4) | ND | ||
| Postnatal antibiotics started N (%) | |||||
| Penicillin G + Tobramycin | 25 (86) | 25 (86) | ND | ||
| Penicillin G | 4 (14) | 4 (14) | ND | ||
| Antibioticsc before 6 mo. N(%) | 6 (13) | 3 (7) | 2 (7) | 4 (14) | 0.63 |
aOne infant had a missing Apgar value at 10 minutes.
bIn the first trimester of pregnancy, BMI body mass index (normal values 20–25).
cMainly β-lactam antibiotics given during infancy for respiratory infections of the infants, including amoxicillin (N = 6), amoxicillin-clavunate (N = 4), cefuroxime or ceftriaxone (N = 2).
dP value indicates the statistical significance of variance analysis for continuous variables, i.e. the difference between all groups, and that of Pearson chi-square test for categorical variables.
ND statistical testing not done as the groups were originally created based on these differences in perinatal antibiotic use. Furthermore, postanatal antibiotics were given only for newborn infants with clinical problems after birth reflected by low Apgar points. Lactobacillus reuteri was given only for infants on postnatal antibiotics as a part of their routine clinical care according to the local policy.