Baseline characteristics
| Infant | Overall n=596 | Mother CMV seronegative n=139 | Mother CMV seropositive | P value* | |
| No postnatal CMV infection n=424 | Postnatal CMV Infection n=33 | ||||
| Gestational age—weeks, mean (SD) | 27.9 (2.6) | 28.2 (2.3) | 27.8 (2.7) | 27.5 (2.3) | 0.18 |
| Birth weight—g, mean (SD) | 1016 (273) | 1036 (269) | 1012 (277) | 981 (254) | 0.50 |
| Male sex, n (%) | 300 (50) | 74 (53) | 205 (48) | 21 (64) | 0.18 |
| Race, n (%) | |||||
| Black | 345 (58) | 50 (36) | 277 (65) | 18 (55) | <0.001 |
| White | 199 (33) | 77 (55) | 113 (27) | 9 (27) | |
| Asian | 25 (4.2) | 4 (2.9) | 17 (4.0) | 4 (12) | |
| More than one race | 23 (3.9) | 7 (5.0) | 14 (3.3) | 2 (6.1) | |
| Other† | 4 (0.7) | 1 (0.7) | 3 (0.7) | 0 | |
| Hispanic ethnicity, n (%) | 50 (8.4) | 6 (4.3) | 40 (9.4) | 4 (12) | 0.12 |
| Singleton birth, n (%) | 410 (69) | 101 (73) | 287 (68) | 22 (67) | 0.53 |
| Small for gestational age, n (%) | 105 (26) | 31 (31) | 68 (24) | 6 (27) | 0.38 |
| Born outside study hospital, n (%) | 7 (1.2) | 2 (1.4) | 5 (1.2) | 0 | 0.79 |
| 1 min Apgar score,‡ median (IQR) | 5 (4) | 5 (5) | 5 (5) | 5 (4) | 0.03 |
| 5 min Apgar score,‡ median (IQR) | 8 (2) | 9 (1) | 8 (2) | 7 (2) | <0.001 |
| Score for Neonatal Acute Physiology mean (SD) | 10.3 (5.4) | 10.1 (5.9) | 10.4 (5.3) | 10.5 (5.4) | 0.86 |
| Mother | n=514 | n=122 | n=360 | n=32 | |
| Age—years, mean (SD) | 29.5 (6.5) | 29.4 (5.9) | 29.4 (6.7) | 30.7 (7.2) | 0.55 |
| At least one prenatal visit, n (%) | 479 (93.2) | 120 (98.4) | 330 (91.7) | 29 (90.6) | 0.03 |
| Premature rupture of membranes,§ n (%) | 195 (38) | 44 (36) | 129 (36) | 22 (6) | 0.001 |
| Rupture of membranes>18 hours,§ n (%) | 109 (21) | 29 (24) | 68 (19) | 12 (38) | 0.04 |
| Chorioamnionitis, n (%) | 77 (15) | 10 (8.2) | 63 (18) | 4 (13) | 0.04 |
| Caesarean delivery, n (%) | 387 (75) | 96 (79) | 268 (74) | 23 (72) | 0.58 |
| Receipt of antenatal steroids, n (%) | 429 (83) | 104 (85) | 298 (83) | 27 (84) | 0.81 |
| Indications for premature delivery, n (%) | |||||
| Isolated spontaneous labour | 150 (29) | 27 (22) | 117 (33) | 6 (19) | 0.04 |
| Premature rupture of membranes | 141 (27) | 35 (29) | 89 (25) | 17 (53) | 0.002 |
| Pregnancy-associated hypertension | 121 (24) | 30 (25) | 87 (24) | 4 (13) | 0.31 |
| Fetal distress/Poor biophysical profile | 72 (14) | 15 (12) | 51 (14) | 6 (19) | 0.65 |
| Bleeding complication | 51 (9.9) | 12 (9.8) | 36 (10) | 3 (9.4) | 0.99 |
*Significant pairwise comparisons among infants with and without postnatal CMV infection as follows: premature rupture of membranes, p<0.001; rupture of membranes>18 hours, p=0.01; indication for delivery: premature rupture of membranes, p<0.001.
†Other race category includes American Indian and Alaska Native, Native Hawaiian or Other Pacific Islander, or other unidentified race.
‡1 minute Apgar score is missing for four infants. 5 min Apgar score is missing for two infants.
§Rupture of membranes unknown for one mother.
CMV, cytomegalovirus.