Characteristics of infants and mothers at inclusion in the study and according to gestational age and pathogens
| All study infants | Late preterm (34–36 WG) | Term (≥37 WG) | |||||||
| Total (N=108) | GBS (n=54) |
E. coli
(n=35) | Total (n=25) | GBS (n=7) |
E. coli
(n=15) | Total (n=83) | GBS (n=47) |
E. coli
(n=20) | |
| Birth weight, g, mean (SD) | |||||||||
| ≤2500 | 22 (20.4) | 5 (9.3) | 14 (40) | 18 (72.0) | 4 (57.1) | 12 (80) | 4 (4.8) | 1 (2.1) | 2 (10) |
| >2500 | 86 (79.6) | 49 (90.7) | 21 (60) | 7 (28.0) | 3 (42.9) | 3 (20) | 79 (95.2) | 46 (97.9) | 18 (90) |
| Apgar score ≥7 at 5 min, n (%) | 90 (83.3) | 48 (88.9) | 29 (82.9) | 23 (92.0) | 7 (100) | 14 (93.3) | 67 (80.7) | 41 (87.2) | 15 (75) |
| Method of delivery, n (%) | |||||||||
| Vaginal | 83 (76.9) | 45 (83.3) | 27 (77.1) | 19 (76.0) | 6 (85.7) | 11 (73.3) | 64 (77.1) | 39 (83.0) | 16 (80) |
| Caesarean section | 25 (23.1) | 9 (16.7) | 8 (22.9) | 6 (24.0) | 1 (14.3) | 4 (26.7) | 19 (22.9) | 8 (17.0) | 4 (20) |
| Mother’s age, years | |||||||||
| Mean (SD) | 30.6 (5.0) | 30.3 (5.6) | 31.3 (4.3) | 32.2 (3.8) | 32.6 (5.2) | 31.7 (3.1) | 30.1 (5.3) | 30.0 (5.6) | 30.9 (5.0) |
| Range | 18–42 | 18–42 | 20–40 | 25–40 | 25–40 | 26–38 | 18–42 | 18–42 | 20–40 |
| Antenatal risk factors, n (%) | |||||||||
| No GBS screening test | 15 (13.9) | 8 (14.8) | 5 (14.3) | 6 (24.0) | 2 (28.2) | 3 (20) | 9 (10.8) | 6 (12.8) | 2 (10) |
| GBS screening test* performed | 93 (86.1) | 46 (85.2) | 30 (85.7) | 19 (76.0) | 5 (71.4) | 12 (80) | 74 (89.2) | 41 (87.2) | 18 (90) |
| Positive | 14 (15.1) | 11 (23.9) | 2 (6.7) | 3 (15.8) | 2 (40.0) | 0 | 11 (14.9) | 9 (22.0) | 2 (11.1) |
| Negative | 79 (84.9) | 35 (76.1) | 28 (93.3) | 16 (84.2) | 3 (60.0) | 12 (100) | 63 (85.1) | 32 (78.0) | 16 (88.9) |
| History of neonatal GBS infection | 3 (2.8) | 1 (1.9) | 1 (2.9) | 1 (4.0) | 0 | 1 (6.7) | 2 (2.4) | 1 (2.1) | 0 |
| Membrane rupture >12 hours | 32 (29.6) | 5 (9.3) | 21 (60.0) | 11 (44.0) | 1 (14.3) | 10 (66.7) | 21 (25.3) | 4 (8.5) | 11 (55.0) |
| Intrapartum maternal temperature >38°C | 41 (38.0) | 19 (35.2) | 11 (31.4) | 9 (36.0) | 2 (28.6) | 5 (33.3) | 32 (38.6) | 17 (36.2) | 6 (30) |
| No risk factors† | 34 (31.5) | 22 (40.7) | 8 (22.9) | 2 (8.0) | 1 (14.3) | 1 (6.7) | 32 (38.6) | 21 (44.7) | 7 (35.0) |
| No GBS screening test and no other risk factor | 6 (5.6) | 4 (7.4) | 2 (5.7) | 2 (8.0) | 1 (14.3) | 1 (6.7) | 4 (4.8) | 3 (6.4) | 1 (5.0) |
| Antibiotic treatment within 3 days before labour onset, n (%) | 16 (14.8) | 0 | 14 (40.0) | 8 (32.0) | 0 | 8 (53.3) | 8 (9.6) | 0 | 6 (30) |
| Intrapartum antibiotic treatment, n (%) | |||||||||
| No antibiotic treatment | 65 (60.2) | 42 (77.8) | 14 (40.0) | 9 (36.0) | 5 (71.4) | 3 (20) | 56 (67.5) | 37 (78.7) | 11 (55) |
| Adequate treatment | 26 (24.1) | 0 | 20 (57.1) | 13 (52.0) | 0 | 12 (80) | 13 (15.7) | 0 | 8 (40) |
| Inadequate treatment | 17 (15.7) | 12 (22.2) | 1 (2.9) | 3 (12.0) | 2 (28.6) | 0 | 14 (16.9) | 10 (21.3) | 1 (5) |
*Vaginal swab (PCR or microbiological culture) and/or urine culture.
†Negative GBS screening test, no intrapartum maternal temperature >38°C, no membrane rupture >12 hours, no unexplained preterm birth and no history of neonatal GBS infection.
E. coli, Escherichia coli; GBS, group B Streptococcus; WG, weeks of gestation.