Screening and diagnosis of gestational diabetes, and population characteristics for pregnant people in British Columbia, Canada (> 28 weeks’ gestation at delivery and without pre-existing diabetes) for selected years between 2005 and 2019
| Characteristic | No. (%) of pregnant people | ||||
|---|---|---|---|---|---|
| 2005 n = 33 341 | 2009 n = 37 703 | 2012 n = 37 158 | 2015 n = 37 089 | 2019 n = 36 417 | |
| Gestational diabetes | |||||
| Diagnosis | 2401 (7.2) | 3029 (8.0) | 3842 (10.3) | 4421 (11.9) | 5337 (14.7) |
| Screening completion | 29 078 (87.2) | 33 543 (89.0) | 33 526 (90.2) | 34 226 (92.3) | 34 785 (95.5) |
| Screening method* | |||||
| Two-step | 29 078 (87.2) | 33 543 (89.0) | 16 609 (44.7) | 20 015 (54.0) | 21 042 (57.8) |
| One-step | 0 (0.0) | 0 (0.0) | 16 917 (45.5) | 14 211 (38.3) | 13 743 (37.7) |
| Not screened or no data | 4263 (12.8) | 4160 (11.0) | 3632 (9.8) | 2863 (7.7) | 1632 (4.5) |
| One-step screening (among screened pregnancies) | 0 (0.0) | 0 (0.0) | 16 917 (50.5) | 14 211 (41.5) | 13 743 (39.5) |
| Patient | |||||
| Nulliparous | 15 220 (45.7) | 17 476 (46.4) | 17 134 (46.1) | 17 365 (46.8) | 16 908 (46.4) |
| Pre-pregnancy body mass index, kg/m2 | |||||
| < 24.9 | 16 145 (48.4) | 16 650 (44.2) | 18 442 (49.6) | 18 637 (50.2) | 17 838 (49.0) |
| 25.0–29.9 | 4809 (14.4) | 5318 (14.1) | 5860 (15.8) | 6072 (16.4) | 7011 (19.3) |
| 30.0–34.9 | 1684 (5.1) | 1981 (5.3) | 2269 (6.1) | 2412 (6.5) | 2839 (7.8) |
| > 35.0 | 1003 (3.0) | 1193 (3.2) | 1342 (3.6) | 1512 (4.1) | 1828 (5.0) |
| Missing body mass index | 9700 (29.1) | 12 561 (33.3) | 9245 (24.9) | 8456 (22.8) | 6901 (18.9) |
| Age of mother or birthing person at delivery, yr | |||||
| < 25 | 5760 (17.3) | 6071 (16.1) | 4912 (13.2) | 4110 (11.1) | 3046 (8.4) |
| 25–34 | 20 247 (60.7) | 22 899 (60.7) | 23 393 (63.0) | 23 756 (64.1) | 22 747 (62.5) |
| ≥ 35 | 7334 (22.0) | 8733 (23.2) | 8853 (23.8) | 9223 (24.9) | 10 624 (29.2) |
| Multifetal pregnancy | 489 (1.5) | 565 (1.5) | 581 (1.6) | 567 (1.5) | 516 (1.4) |
| Medical or obstetric complications (composite)† | 1428 (4.3) | 1699 (4.5) | 1844 (5.0) | 2154 (5.8) | 2539 (7.0) |
| Mother or birthing person’s region of birth | |||||
| Asia | 7152 (21.6) | 8212 (21.9) | 8641 (23.3) | 9003 (24.4) | 9761 (26.9) |
| Canada or United States‡ | 23 269 (69.8) | 26 286 (69.7) | 25 223 (67.9) | 24 975 (67.3) | 23 240 (63.8) |
| All other regions | 2920 (8.8) | 3205 (8.5) | 3294 (8.9) | 3111 (8.4) | 3416 (9.4) |
| Midwife-led prenatal care | 1247 (3.7) | 4239 (11.2) | 6078 (16.4) | 7810 (21.1) | 9595 (26.3) |
| Inadequate prenatal care§ | 2912 (8.7) | 2525 (6.7) | 2401 (6.5) | 2166 (5.8) | 2080 (5.7) |
↵* The 1-step screening method is a single, 2-hour, 75-g oral glucose tolerance test, as per criteria from the International Association of Diabetes in Pregnancy Study Groups. (8) The 2-step screening method is a 1-hour, 50-g glucose challenge test, followed by an oral glucose tolerance test (before October 2010: a 3-hour, 100-g test; after October 2010: a 2-hour, 75-g test) for patients who screen positive.
↵† Medical or obstetric complications composite includes pre-existing hypertension, pregnancy-complicating conditions or diseases, previous stillbirth, previous neonatal death or congenital anomaly in a previous birth.
↵‡ Missing data were included in this group and represented < 0.5% of the cohort.
↵§ As defined by “inadequate” versus all other prenatal care usage using the Adequacy of Prenatal Care Utilization Index. (22)