Table 2 Maternal and newborn characteristics by maternal age at delivery in a cohort of 24,294 infants from the Copenhagen Baby Heart Study, Denmark, 2016–2018
Maternal age at delivery | Number (%) | ||||
|---|---|---|---|---|---|
< 25 years N = 1128 | 25–29 years N = 6879 | 30–34 years N = 9824 | 35–39 years N = 5139 | ≥ 40 years N = 1324 | |
Maternal Characteristics | |||||
Maternal prepregnancy BMI | |||||
< 18.5 | 71 (6.3) | 296 (4.3) | 388 (3.9) | 160 (3.1) | 30 (2.3) |
18.5–24.9 | 711 (63.0) | 4740 (68.9) | 6961 (70.9) | 3520 (68.5) | 876 (66.2) |
25.0–29.9 | 216 (19.1) | 1261 (18.3) | 1721 (17.5) | 982 (19.1) | 297 (22.4) |
30.0–34.9 | 78 (6.9) | 377 (5.5) | 506 (5.2) | 323 (6.3) | 83 (6.3) |
≥ 35 | 41 (3.6) | 188 (2.7) | 222 (2.3) | 141 (2.7) | 33 (2.5) |
Missing | 11 (1.0) | 17 (0.2) | 26 (0.3) | 13 (0.3) | 5 (0.4) |
First-trimester smoking | |||||
Yes | 138 (12.2) | 220 (3.2) | 234 (2.4) | 119 (2.3) | 29 (2.2) |
No | 934 (82.8) | 6480 (94.2) | 9343 (95.1) | 4867 (94.7) | 1260 (95.2) |
Missing | 56 (5.0) | 179 (2.6) | 247 (2.5) | 153 (3.0) | 35 (2.6) |
Newborn Characteristics | |||||
Sex | |||||
Male | 607 (53.8) | 3498 (50.9) | 5053 (51.4) | 2704 (52.6) | 683 (51.6) |
Female | 521 (46.2) | 3381 (49.1) | 4771 (48.6) | 2435 (47.4) | 641 (48.4) |
Gestational age at birth (weeks) | |||||
37 | 84 (7.4) | 377 (5.5) | 537 (5.5) | 322 (6.3) | 121 (9.1) |
38 | 143 (12.7) | 889 (12.9) | 1255 (12.8) | 783 (15.2) | 245 (18.5) |
39 | 266 (23.6) | 1529 (22.2) | 2127 (21.7) | 1062 (20.7) | 288 (21.8) |
40 | 348 (30.9) | 2134 (31.0) | 2970 (30.2) | 1530 (29.8) | 373 (28.2) |
≥ 41 | 287 (25.4) | 1950(28.3) | 2935 (29.8) | 1442 (28.0) | 297(22.4) |
Birthweight (g) | |||||
< 2500 | * | 92 (1.3) | 128 (1.3) | 90 (1.8) | * |
2500–2999 | 140 (12.4) | 713 (10.4) | 1115 (11.3) | 540 (10.5) | 193 (14.6) |
3000–3499 | 406 (36.0) | 2424 (35.2) | 3390 (34.5) | 1733 (33.7) | 439 (33.2) |
3500–3999 | 389 (34.5) | 2620 (38.1) | 3596 (36.6) | 1856 (36.1) | 444 (33.5) |
≥ 4000 | 167 (14.8) | 1018 (14.8) | 1580 (16.1) | 914 (17.8) | 204 (15.4) |
Missing | * | 12 (0.2) | 15 (0.2) | 6 (0.1) | * |
Birth length (cm) | |||||
< 50 | 174 (15.4) | 828 (12.0) | 1236 (12.6) | 638 (12.4) | 225 (17.0) |
50–54.9 | 860 (76.2) | 5396 (78.4) | 7555 (76.9) | 3964 (77.1) | 969 (73.2) |
≥ 55 | 87 (7.7) | 624 (9.1) | 990 (10.1) | 517 (10.1) | 123 (9.3) |
Missing | 7 (0.6) | 31 (0.5) | 43 (0.4) | 20 (0.4) | 7 (0.5) |
Congenital heart defecta | |||||
Yes | 74 (6.6) | 478 (6.9) | 708 (7.2) | 346 (6.7) | 92 (6.9) |
No | 1054 (93.4) | 6401 (93.1) | 9116 (92.8) | 4793 (93.3) | 1232 (93.1) |