Background
Methods
Study design
Classification of birth weight by customized and population charts
Childhood growth, cardio-metabolic, and respiratory outcomes
Statistical analyses
Results
Population characteristics
Customized classificationa | Population classificationb | |||||
---|---|---|---|---|---|---|
Small size for gestational age | Appropriate size for gestational age | Large size for gestational age | Small size for gestational age | Appropriate size for gestational age | Large size for gestational age | |
n = 605 | n = 4842 | n = 605 | n = 605 | n = 4842 | n = 605 | |
Maternal characteristics | ||||||
Age, median (95% range), years | 30.5 (19.7 to 39.8) | 30.6 (19.6 to 39.1) | 30.7 (20.1 to 39.3) | 29.7 (19.0 to 39.6) | 30.5 (19.8 to 39.0) | 31.6 (21.5 to 39.8) |
Height, mean (SD) (cm) | 166.2 (7.4) | 167.7 (7.4) | 169.3 (7.3) | 164.3 (7.1) | 167.7 (7.3) | 170.6 (7.2) |
Weight, mean (SD) (kg) | 71.8 (16.3) | 68.7 (12.3) | 70.4 (12.9) | 64.8 (12.5) | 68.8 (12.4) | 76.0 (14.6) |
Body mass index, mean (SD) (kg/m2) | 26 (5.6) | 24.4 (4.1) | 24.6 (4.4) | 24.0 (4.4) | 24.5 (4.2) | 26.2 (5.1) |
Obesity | 123 (20.3) | 485 (10.0) | 60 (9.9) | 58 (9.6) | 491 (10.1) | 119 (19.7) |
Education, no. higher (%) | 217 (37) | 2137 (45) | 306 (52) | 206 (34.8) | 2141 (45.2) | 313 (52.8) |
Ethnicity, no. (%) Dutch/European | 332 (54.9) | 2899 (59.9) | 395 (65.3) | 283 (46.8) | 2911 (60.1) | 432 (71.4) |
Parity, no. Nulliparous (%) | 348 (57.5) | 2792 (57.7) | 330 (54.5) | 434 (71.7) | 2787 (57.6) | 249 (41.2) |
Smoking, no. (%) | ||||||
None | 440 (66.3) | 3755 (73.9) | 510 (79.6) | 379 (65.2) | 3466 (74.4) | 462 (79.4) |
Early pregnancy only | 50 (7.5) | 453 (8.9) | 61 (9.5) | 45 (7.7) | 418 (9.0) | 55 (9.5) |
Continued | 174 (26.2) | 875 (17.2) | 70 (10.9) | 157 (27.0) | 773 (16.6) | 65 (11.2) |
Birth characteristics | ||||||
Males, no. (%) | 295 (42.8) | 2665 (50.5) | 390 (59.2) | 242 (40.0) | 2435 (50.3) | 362 (59.8) |
Gestational age, median (95% range) weeks | 39.7 (32.0 to 42.3) | 40.3 (36.3 to 42.3) | 39.9 (36.2 to 42.1) | 40.3 (36.3 to 42.4) | 40.3 (36.3 to 42.4) | 39.9 (36.0 to 42.0) |
Birth weight, mean (SD) grams | 2622 (483) | 3440 (425) | 4176 (396) | 2581 (421) | 3442 (416) | 4230 (399) |
Preterm birth, no. (%) | 74 (12.2) | 184 (3.8) | 21 (3.5) | 66 (10.9) | 187 (3.9) | 26 (4.3) |
Cesarean delivery, no. (%) | 107 (18.9) | 467 (10.5) | 94 (17.1) | 102 (18.2) | 478 (10.8) | 88 (16.0) |
Assisted delivery, no. (%) | 75 (13.3) | 644 (14.5) | 75 (13.6) | 59 (15.9) | 651 (14.7) | 54 (9.9) |
APGAR score below 7 at 5 min, no. (%) | 16 (2.8) | 40 (0.9) | 4 (0.9) | 12 (2.1) | 44 (0.9) | 5 (0.9) |
Characteristics of newborns classified as SGA or LGA by customized or population charts only
Customized classificationa | ||||
---|---|---|---|---|
Small size for gestational age n = 605 | Appropriate size for gestational age n = 4842 | Large size for gestational age n = 605 | ||
Population classificationb | Small size for gestational age n = 605 | 455 (75.2) | 150 (24.8) | 0 (0) |
Appropriate size for gestational age n = 4842 | 150 (24.8) | 4563 (94.2) | 129 (21.3) | |
Large size for gestational age n = 605 | 0 (0) | 129 (21.3) | 476 (78.7) |
Small size for gestational age | Large size for gestational age | |||||
---|---|---|---|---|---|---|
Customized onlya | Customized and populationb | p value | Customized onlya | Customized and populationb | p value | |
n = 150 | n = 455 | n = 129 | n = 476 | |||
Maternal characteristics | ||||||
Age, median (95% range), years | 30.5 (20.4 to 39.0) | 30.5 (19.6 to 40.3) | 0.215 | 27.7 (19.9 to 36.0) | 31.2 (20.7 to 40.0) | < 0.001 |
Height, mean (SD) (cm) | 169.0 (7.8) | 165.3 (7.0) | < 0.001 | 165.7 (6.4) | 170.3 (7.2) | < 0.001 |
Weight, mean (SD) (kg) | 85.4 (18.1) | 67.3 (12.8) | < 0.001 | 60.8 (7.6) | 72.9 (12.8) | < 0.001 |
Body mass index, mean (SD) (kg/m2) | 30.0 (6.5) | 24.6 (4.6) | < 0.001 | 22.2 (2.5) | 25.2 (4.6) | < 0.001 |
Obesity, no. (%) | 67 (44.7) | 56 (12.3) | < 0.001 | 2 (1.6) | 58 (12.2) | < 0.001 |
Education, no. higher (%) | 51 (34.0) | 166 (36.5) | 0.582 | 57 (44.2) | 249 (52.3) | 0.102 |
Race/ethnicity, no. (%) Dutch or European | 101 (67.3) | 253 (55.6) | 0.011 | 56 (43.4) | 327 (68.7) | < 0.001 |
Parity, no. nulliparous (%) | 50 (33.3) | 298 (65.5) | < 0.001 | 108 (83.7) | 222 (46.6) | < 0.001 |
Smoking, no. (%) | 0.055 | 0.711 | ||||
None | 109 (75.2) | 282 (64.5) | 100 (80.0) | 366 (79.2) | ||
Early pregnancy only | 9 (6.2) | 33 (7.6) | 14 (11.2) | 45 (9.7) | ||
Continued | 27 (18.6) | 122 (27.9) | 11 (8.8) | 51 (11.0) | ||
Birth characteristics | ||||||
Males, no. (%) | 67 (44.7) | 185 (40.7) | 0.388 | 72 (55.8) | 281 (59.0) | 0.511 |
Gestational age, median (95% range), weeks | 40.1 (32.6 to 42.4) | 39.6 (31.9 to 42.3) | 0.007 | 40.0 (36.4 to 42.4) | 39.9 (36.1 to 42.0) | 0.058 |
Birth weight, mean (SD) grams | 2981 (412) | 2503 (445) | < 0.001 | 3922 (319) | 4245 (386) | < 0.001 |
Preterm birth, no. (%) | 12 (8.0) | 62 (13.6) | 0.068 | 3 (2.3) | 18 (3.8) | 0.423 |
Cesarean delivery, no. (%) | 19 (13.4) | 88 (20.8) | 0.051 | 20 (16.7) | 74 (17.2) | 0.897 |
Assisted delivery, no. (%) | 9 (6.3) | 66 (15.6) | 0.005 | 27 (22.5) | 48 (11.1) | 0.001 |
APGAR score below 7 at 5 min, no. (%) | 5 (3.4) | 11 (2.5) | 0.549 | 0 (0) | 5 (1.1) | 0.237 |