| |
PTL/PTB mothers
|
Non-PTL/PTB mothers
|
P –valuea
|
|---|
|
N = 2147
|
N = 8778
|
|---|
|
N (%)
|
N (%)
|
|---|
|
Year of delivery
|
0.3403
|
|
2009
|
395 (18.4)
|
1645 (18.7)
| |
|
2010
|
420 (19.6)
|
1726 (19.7)
| |
|
2011
|
413 (19.2)
|
1819 (20.7)
| |
|
2012
|
472 (22.0)
|
1778 (20.3)
| |
|
2013
|
447 (20.8)
|
1810 (20.6)
| |
|
Maternal age at deliveryb
|
< 0.0001
|
|
12–18 years
|
48 (2.2)
|
95 (1.1)
| |
|
19–30 years
|
1276 (59.4)
|
5194 (59.2)
| |
|
31–35 years
|
496 (23.1)
|
2232 (25.4)
| |
|
36–44 years
|
327 (15.2)
|
1257 (14.3)
| |
|
Nulliparousc
|
1360 (63.3)
|
5224 (59.5)
|
0.0011
|
|
Caesarean section
|
885 (41.2)
|
2769 (31.5)
|
< 0.0001
|
|
Birth plurality
|
< 0.0001
|
|
Singleton
|
1969 (91.7)
|
8709 (99.2)
| |
|
Twin
|
173 (8.1)
|
64 (0.0)
| |
|
Other multiple
|
5 (0.0)
|
3 (0.0)
| |
|
Charlson Comorbidity Indexd
|
0.0142
|
|
0
|
1750 (81.5)
|
7332 (83.5)
| |
|
1
|
315 (14.7)
|
1155 (13.2)
| |
|
2
|
54 (2.5)
|
230 (2.6)
| |
|
3
|
21 (1.0)
|
41 (0.5)
| |
|
4+
|
7 (0.3)
|
20 (0.2)
| |
|
Selected comorbiditiesd
|
|
Gestational diabetes
|
237 (11.0)
|
893 (10.2)
|
0.2378
|
|
Hypertension
|
93 (4.3)
|
243 (2.8)
|
0.0002
|
|
Depression
|
83 (3.9)
|
334 (3.8)
|
0.8950
|
|
Hypotension
|
66 (3.1)
|
268 (3.1)
|
0.9597
|
|
Diabetes mellitus
|
50 (2.3)
|
113 (1.3)
|
0.0004
|
- aP-values compare PTL/PTB mothers with non-PTL/PTB mothers, and are calculated using the chi-squared test/Fisher’s Exact test in instances when expected cell counts < 5
- bValues are rounded to the nearest whole number
- cRefers to parity preceding index delivery
- dMeasured during the nine-month baseline period, diagnoses in inpatient or outpatient setting
- Abbreviations: PTB preterm birth, PTL preterm labour
