Maternal/obstetrical and neonatal characteristics stratified by gestational age
| Characteristic; gestational age, wk | Ontario n = 6543 | France n = 4300 | Standardized difference (95% CI) |
|---|---|---|---|
| Maternal age, yr, mean ± SD | |||
| 22–26 | 30.43 ± 5.98 | 29.10 ± 5.96 | 0.22 (0.18 to 0.26) |
| 27–31 | 31.08 ± 6.01 | 29.67 ± 6.04 | 0.23 (0.19 to 0.27) |
| 32–34 | 30.67 ± 5.85 | 29.94 ± 5.54 | 0.13 (0.09 to 0.17) |
| Morbidity,* no. (col %†) | |||
| 22–26 | 350 (47.36) | 436 (49.32) | −0.08 (−0.12 to −0.04) |
| 27–31 | 770 (46.03) | 1114 (45.71) | 0.01 (−0.03 to 0.05) |
| 32–34 | 1756 (44.74) | 447 (45.66) | −0.04 (−0.08 to 0.00) |
| Gestational diabetes, no. (col %†) | |||
| 22–26 | 21 (3.49) | 31 (3.88) | −0.11 (−0.15 to −0.07) |
| 27–31 | 120 (8.50) | 190 (8.45) | 0.01 (−0.03 to 0.05) |
| 32–34 | 323 (9.13) | 88 (9.78) | −0.08 (−0.12 to −0.04) |
| Gestational hypertension, no. (col %†) | |||
| 22–26 | 52 (8.51) | 104 (11.76) | −0.36 (−0.40 to −0.32) |
| 27–31 | 236 (16.65) | 585 (24.00) | −0.46 (−0.50 to −0.42) |
| 32–34 | 541 (14.93) | 175 (17.88) | −0.22 (−0.26 to −0.18) |
| Assisted reproductive technology, no. (col %†) | |||
| 22–26 | 83 (11.66) | 130 (15.40) | −0.32 (−0.36 to −0.28) |
| 27–31 | 186 (11.50) | 266 (11.32) | 0.02 (−0.02 to 0.06) |
| 32–34 | 388 (10.06) | 122 (12.90) | −0.28 (−0.32 to −0.24) |
| Cesarean delivery, no. (col %†) | |||
| 22–26 | 285 (37.30) | 316 (36.41) | 0.04 (0.00 to 0.08) |
| 27–31 | 980 (56.39) | 1671 (69.34) | −0.56 (−0.60 to −0.52) |
| 32–34 | 1924 (47.61) | 523 (53.97) | −0.26 (−0.30 to −0.22) |
| Induction of labour, no. (col %†) | |||
| 22–26 | 60 (7.85) | 28 (3.24) | 0.89 (0.85 to 0.93) |
| 27–31 | 53 (3.05) | 41 (1.75) | 0.56 (0.52 to 0.60) |
| 32–34 | 431 (10.67) | 94 (9.98) | 0.07 (0.03 to 0.11) |
| Multifetal pregnancy, no. (col %†) | |||
| 22–26 | 103 (13.48) | 167 (18.89) | −0.40 (−0.44 to −0.36) |
| 27–31 | 308 (17.72) | 455 (18.67) | −0.06 (−0.10 to −0.02) |
| 32–34 | 743 (18.39) | 219 (22.37) | −0.25 (−0.29 to −0.21) |
| Antenatal steroids, no. (col %†) | |||
| 22–26 | 444 (60.33) | 552 (64.71) | −0.19 (−0.23 to −0.15) |
| 27–31 | 1292 (78.30) | 1987 (83.17) | −0.31 (−0.35 to −0.27) |
| 32–34 | 1728 (45.43) | 685 (71.58) | −1.16 (−1.20 to −1.12) |
| Level 3 care, no. (col %†) | |||
| 22–26 | 513 (68.04) | 704 (79.64) | −0.61 (−0.65 to −0.57) |
| 27–31 | 1112 (64.43) | 2064 (84.69) | −1.13 (−1.17 to −1.09) |
| 32–34 | 1186 (29.52) | 490 (50.05) | −0.90 (−0.94 to −0.86) |
| Birth weight, g, mean ± SD | |||
| 22–26 | 906 ± 710 | 748 ± 161 | 0.36 (0.32 to 0.40) |
| 27–31 | 1408 ± 423 | 1275 ± 326 | 0.36 (0.32 to 0.40) |
| 32–34 | 2123 ± 458 | 1982 ± 384 | 0.33 (0.29 to 0.37) |
| Male sex, no. (col %‡) | |||
| 22–26 | 489 (56.34) | 558 (52.99) | 0.14 (0.10 to 0.18) |
| 27–31 | 1131 (54.64) | 1537 (52.84) | 0.07 (0.03 to 0.11) |
| 32–34 | 2666 (55.50) | 647 (53.69) | 0.07 (0.03 to 0.11) |
Note: CI = confidence interval, SD = standard deviation.
↵* Any chronic medical condition for which the mother had been diagnosed, or for which she was being treated, before pregnancy, such as psychiatric conditions, kidney disease and cardiac disease.
↵† col % = column percentage, calculated with a denominator of mothers within the respective gestational age group.
↵‡ col % = column percentage, calculated with a denominator of infants within the respective gestational age group.