Frequencies and proportions of maternal characteristics by antenatal model of care, British Columbia, 2005–2012 (n=57 872)
| Characteristics | Antenatal model of care | ||
| MW | GP | OB | |
| n=4705 (%) | n=45 114 (%) | n=8053 (%) | |
| Age (years) | |||
| 14–19 | 155 (3.29) | 4697 (10.41) | 338 (4.20) |
| 20–24 | 893 (18.98) | 14 789 (32.78) | 1447 (17.97) |
| 25–29 | 1619 (34.41) | 13 161 (29.17) | 2303 (28.60) |
| 30–34 | 1362 (28.95) | 7966 (17.66) | 2113 (26.24) |
| 35–39 | 573 (12.18) | 3730 (8.27) | 1387 (17.22) |
| ≥40 | 103 (2.19) | 771 (1.71) | 465 (5.77) |
| Parity* | |||
| Nullipara | 2177 (46.27) | 23 141 (51.30) | 3617 (44.91) |
| Multipara | 2528 (53.73) | 21 972 (48.70) | 4435 (55.07) |
| Medical risk†‡ | 14 (0.30) | 414 (0.92) | 132 (1.64) |
| Prior obstetric risk†§ | 124 (2.64) | 1669 (3.70) | 478 (5.94) |
| Mental illness†¶ | 1020 (21.68) | 5146 (11.41) | 610 (7.57) |
| Receiving social assistance† | 310 (6.59) | 5833 (12.93) | 814 (10.11) |
| Pre-pregnancy body mass index (BMI)** | |||
| Underweight | 229 (4.87) | 2300 (5.10) | 519 (6.44) |
| Normal | 2612 (55.52) | 16 777 (37.19) | 2990 (37.13) |
| Overweight | 689 (14.64) | 5829 (12.92) | 877 (10.89) |
| Obese | 335 (7.12) | 3792 (8.41) | 479 (5.95) |
| Unknown | 840 (17.85) | 16 416 (36.39) | 3188 (39.59) |
| Smoking status | |||
| Never | 992 (21.08) | 6666 (14.78) | 1868 (23.20) |
| Former | 690 (14.67) | 5028 (11.15) | 434 (5.39) |
| Current | 471 (10.01) | 9910 (21.97) | 800 (9.93) |
| Unknown | 2552 (54.24) | 23 510 (52.11) | 4951 (61.48) |
| Substance use in pregnancy†,†† | 179 (3.80) | 3273 (7.25) | 302 (3.75) |
| Alcohol identified as a risk† | 57 (1.21) | 1109 (2.46) | 63 (0.78) |
| Utilisation of prenatal care‡‡ | |||
| Intense | 98 (2.08) | 304 (0.67) | 60 (0.75) |
| Adequate | 1420 (30.18) | 6851 (15.19) | 902 (11.20) |
| Intermediate | 1927 (40.96) | 19 929 (44.17) | 2601 (32.30) |
| Inadequate | 273 (5.80) | 6986 (15.49) | 980 (12.17) |
| Unknown | 987 (20.98) | 11 044 (24.48) | 3510 (43.59) |
| Antepartum morbidity†§§ | 349 (7.42) | 6843 (15.17) | 1955 (24.28) |
| Delivery (year) | |||
| 2005 | 307 (6.52) | 5772 (12.79) | 955 (11.86) |
| 2006 | 437 (9.29) | 6028 (13.36) | 1002 (12.44) |
| 2007 | 471 (10.01) | 6133 (13.59) | 1074 (13.34) |
| 2008 | 512 (10.88) | 5892 (13.06) | 977 (12.13) |
| 2009 | 606 (12.88) | 5640 (12.50) | 910 (11.30) |
| 2010 | 694 (14.75) | 5371 (11.91) | 1000 (12.42) |
| 2011 | 796 (16.92) | 5337 (11.83) | 1014 (12.59) |
| 2012 | 882 (18.75) | 4941 (10.95) | 1121 (13.92) |
| Neighbourhood SEP¶¶ | |||
| High | 624 (13.26) | 4984 (11.05) | 646 (8.02) |
| Low/medium | 4081 (86.74) | 40 130 (88.95) | 7407 (91.98) |
| Local health area (LHA) population demographic*** | |||
| Urban | 4548 (96.66) | 42 489 (94.18) | 7889 (97.96) |
| Rural | 145 (3.08) | 2576 (5.71) | 145 (1.80) |
| Unknown | 12 (0.26) | 49 (0.11) | 19 (0.24) |
| LHA socioeconomic rank††† | |||
| High (best) | 2638 (56.07) | 13 287 (29.45) | 4043 (50.20) |
| Medium | 1472 (31.29) | 22 011 (48.79) | 3197 (39.70) |
| Low | 582 (12.37) | 9710 (21.52) | 739 (9.18) |
| Unknown | 13 (0.28) | 106 (0.23) | 74 (0.92) |
| LHA income inequality rank‡‡‡ | |||
| High (worst) | 1667 (35.43) | 10 635 (23.57) | 4177 (51.87) |
| Medium | 2326 (49.44) | 25 544 (56.62) | 3311 (41.12) |
| Low | 699 (14.86) | 8841 (19.60) | 530 (6.58) |
| Unknown | 13 (0.28) | 94 (0.21) | 35 (0.43) |
| Northern residence†§§§ | 136 (2.89) | 6032 (13.37) | 291 (3.61) |
All characteristics examined differed significantly by model of care (X2 p<0.0001).
*Missing cases amount to five or less.
†Values represent cases classified as ‘Yes’, the remainder of the cases were classified as ‘No’, ‘Unknown’, or were undocumented.
‡Included maternal disease of the respiratory or digestive system, and endocrine, nutritional or metabolic disease.
§Included women with at least one of the following conditions in past pregnancy: infant with major congenital anomaly, neonatal death, stillbirth or one preterm delivery.
¶Included any of the following diagnoses prior to, or during the current pregnancy: anxiety disorder, depression, postpartum depression, bipolar disorder, other/unknown (including schizophrenic, mood and psychotic disorders).
**Classified according to Health Canada’s guidelines.38
††Heroin/opioids, cocaine, methadone, solvents, marijuana or other/unknown drugs used at any time during pregnancy, prescription or other drug use identified as a risk at any time during pregnancy.
‡‡Classifications based on Kotelchuck Adequacy of Prenatal Care Utilization Index.39
§§Included pregnancy-induced hypertension, gestational diabetes (whether or not insulin dependent), anaemia, intrauterine growth restriction, viral disease, infection and parasitic disease, placenta previa without haemorrhage, polyhydramnios or oligohydramnios, antepartum haemorrhage ≥20 weeks, sexually transmitted infection or HIV, or premature separation of the placenta.
¶¶Neighbourhood income quintiles were classified as low/medium (quintiles 1–4) versus high (quintile 5).24
***Rural LHAs had a population <10 000 people.
†††Calculated by the province of BC’s Statistics Division (BC Stats), based on a range of social determinants of health-reflecting area-level economic and social processes, and policy decisions.22
‡‡‡Calculated by BC Stats.22
§§§At the time of delivery, normal residence in BC’s Northern Health Authority.
GP, general practitioner; MW, midwife; OB, obstetrician; SEP, socioeconomic position.