Table 1

Baseline characteristics of the study participants for the total cohort and stratified by Ureaplasma status

No. of participants (%)
Total cohort Ureaplasma positive Ureaplasma negative
(n=121)(n=44)(n=77)
CharacteristicAZMPlaceboAZMPlaceboAZMPlacebo
(n=60)(n=61)(n=19)(n=25)(n=41)(n=36)
Male, n (%)26 (43)32 (52)11 (58)10 (40)15 (37)22 (61)
Race, n (%)
 White36 (60)15 (25)13 (68)5 (20)23 (56)10 (28)
 African-American21 (35)43 (70)6 (32)19 (76)15 (37)24 (67)
 Asian0 (0)1 (2)01 (4)00
 Multiple/biracial3 (5)2 (3)00 (0)3 (7)2 (6)
Hispanic ethnicity, n (%)2 (3)0 (0)0 (0%)0 (0)2 (5)0 (0)
Birth weight, mean (SD), g895 (215)903 (245)897 (195)851 (282)895 (226)939 (213)
Gestational age, mean (SD), weeks26.2 (1.4)26.2 (1.4)25.8 (1.1)25.8 (1.4)26.4 (1.5)26.5 (1.4)
Gestational age strata, n (%)
 240–266 weeks40 (67)43 (70)16 (84)20 (80)24 (59)23 (64)
 270–286 weeks20 (33)18 (30)3 (16)5 (20)17 (41)13 (36)
SGA, n (%)2 (3)1 (2)0 (0)1 (4)2 (5)0 (0)
Preterm labour, n (%)47 (78)49 (80)17 (89)18 (72)30 (73)31 (86)
PPROM, n (%)23 (38)29 (48)9 (47)17 (68)14 (34)12 (33)
Duration rupture of membranes, n (%)
 <1 hour36 (60)29 (48)9 (47)7 (28)27 (66)22 (61)
 ≥1 hour22 (37)29 (48)9 (47)16 (64)13 (32)13 (36)
 Unknown2 (3)3 (5)1 (5)2 (8)1 (2)1 (3)
Maternal Pe-eclampsia, n (%)0 (0)2 (3)0 (0)1 (4)0 (0)1 (3)
Antenatal steroids, n (%)51 (85)48 (79)16 (84)19 (76)35 (85)29 (81)
Maternal macrolide, n (%)
 Erythromycin10 (17)11 (18)4 (21)8 (32)6 (15)3 (8)
 Azithromycin9 (15)9 (15)2 (11)1 (4)7 (17)8 (22)
 Both1 (2)00 (0)01 (2)0 (0)
 Neither40 (67)41 (67)13 (68)16 (64)27 (66)25 (69)
Route of delivery, n (%)
 SVD27 (45)27 (44)9 (47)13 (52)18 (44)14 (39)
 C/S33 (55)34 (56)10 (53)12 (48)23 (56)22 (61)
Apgar 1 min, median (IQR)5 (3,7)4 (2,6)4 (2,8)4 (2,5)5 (3,7)5 (2.5 to 6.5)
Apgar 5 min, median (IQR)7 (6,8)7 (6,8)6.5 (5,8)6 (6,8)7 (6,8)7 (5.5 to 8)
Respiratory support at enrolment, n (%)
 None2 (3)1 (2)1 (5)0 (0)1 (2)1 (3)
 Non-invasive*28 (47)34 (56)10 (53)15 (60)18 (44)19 (53)
 Invasive†30 (50)26 (43)8 (42)10 (40)22 (54)16 (44)
Duration IMV at enrolment, median (IQR), hours24.92920.530.926.522.2
(10.3,52.3)(15.0,46.8)(0.3,53.0)(21.1,49.3)(12,49.2)(10.5,46.4)
Effective FiO2 at enrolment, median (IQR)0.240.250.260.270.220.25
(0.21,0.28)(0.21,0.33)(0.21,0.30)(0.21,0.30)(0.21,0.27)(0.21,0.36)
Postnatal age at time of first dose, mean (SD), hours58.5 (23.1)56.2 (19.4)58.3 (24.1)50.4 (18.7)58.5 (22.9)60.3 (19.0)
Ureaplasma spp. respiratory colonisation, n (%)19 (32)25 (41)19 (100)25 (100)N/AN/A
U. parvum 14 (23)19 (31)14 (74)19 (76)
U. urealyticum 3 (5)4 (7)3 (16)4 (16)
 Both species1 (2)2 (3)1 (5)2 (8)
 Untyped1 (2)0 (0)1 (5)0 (0)
  • *Non-invasive ventilation included oxyhood, low flow nasal cannula, high flow nasal cannula, nasal continuous positive pressure and nasal intermittent positive pressure ventilation.

  • †Invasive ventilation included synchronised intermittent mechanical ventilation, high frequency oscillatory ventilation and high frequency jet ventilation.

  • AZM, azithromycin; C/S, caesarean section; FiO2, fractional inspired oxygen; IMV, intermittent mandatory ventilation; PPROM, preterm premature rupture of membranes; SGA, small for gestational age; SVD, spontaneous vaginal delivery.