Table 1 Characteristics of participants included in the study, stratified by gestational weight gain (GWG)^a

 Maternal age (years)

2843

  Mean ± SD

30.7 ± 4.5

30.8 ± 4.6

30.7 ± 4.6

30.6 ± 4.4

0.639

  ≤ 35-year-old

2277 (80.0)

816 (80.3)

394 (79.0)

1067 (80.3)

0.783

  > 35-year-old

566 (20.0)

200 (19.7)

105 (21.0)

261 (19.7)

 Ethnicity

2902

0.070

  White/Caucasian

2307 (79.5)

843 (80.7)

386 (75.8)

1078 (79.9)

  Other

595 (20.5)

201 (19.3)

123 (24.2)

271 (20.1)

 Time in Canada

2893

0.006*

  Born/ lived in Canada ≥ 5years

2626 (90.8)

943 (90.6)

442 (87.4)

1241 (92.2)

  Lived in Canada <5 years

267 (9.2)

98 (9.4)

64 (12.6)

105 (7.8)

 Education

2904

0.947

  High-school or less

285 (9.8)

100 (9.6)

50 (9.8)

135 (10.0)

  Some or completed post-secondary

2619 (90.2)

943 (90.4)

460 (90.2)

1216 (90.0)

 Household Income

2816

0.172

  < $60 000

467 (16.6)

153 (15.2)

94 (19.0)

220 (16.8)

  ≥ $60 000

2349 (83.4)

856 (84.8)

402 (81.0)

1091 (83.2)

 Employment status

1933

0.042*

  Employed full time

1340 (69.3)

496 (66.5)

215 (65.7)

656 (72.8)

  Employed part-time

497 (25.7)

198 (28.1)

95 (29.1)

204 (22.6)

  Casual employment

96 (5.0)

38 (5.4)

17 (5.2)

41 (4.6)

 Pre-pregnancy weight (kg) (mean ± SD)

2909

70.0 ± 14.2

65.9 ± 12.5

68.1 ± 16.0

73.8 ± 13.7

<0.001*

 Pre-pregnancy BMI (kg/m²) (mean ±SD)

2909

24.2 ± 5.0

24.1 ± 4.3

24.9 ± 5.6

26.7 ± 4.6

<0.001*

 ^aMaternal pre-pregnancy BMI (kg/m²)

2909

<0.001*

  Underweight (<18.5 kg/m²)

132 (4.5)

68 (6.5)

29 (5.7)

35 (2.6)

  Normal weight (18.5- 24.9 kg/m²)

1808 (62.2)

761 (72.8)

356 (69.7)

691 (51.1)

  Overweight (25-29.9 kg/m²)

647 (22.2)

147 (14.1)

56 (11.0)

444 (32.8)

  Obese (≥30.0 kg/m²)

322 (11.1)

69 (6.6)

70 (13.7)

183 (13.5)

 Parity n (%)

2893

0.220

  Nulliparous

1400 (48.4)

497 (47.6)

234 (45.8)

669 (50.0)

  Multiparous

1493 (51.6)

547 (52.4)

277 (54.2)

669 (50.0)

 Gestational age at delivery (mean ±SD)

2737

39.2 ± 1.6

39.3 ± 1.7

39.0 ± 1.7

39.2 ± 1.6

0.053

 Preterm birth rate n (%)

2909

0.357

  < 37 weeks GA

148 (5.4)

48 (4.8)

31 (6.6)

69 (5.5)

  ≥ 37 weeks GA

2589 (94.6)

955 (95.2)

439 (93.4)

1195 (94.5)

 Mode of delivery n (%)

  Vaginal (spontaneous or assisted)

2754

2089 (75.9)

363 (17.4)

787 (37.7)

939 (44.9)

0.045*

  Caesarean Section

665 (24.1)

109 (16.4)

221 (33.2)

335 (50.4)

   Elective C-section

323 (12.8)

112 (12.3)

54 (12.4)

157 (13.3)

   Emergency C-section

331 (13.1)

111 (12.2)

51 (11.7)

169 (14.3)

 Type of labour

2424

  Spontaneous labour

1472 (60.7)

561 (64.4)

251 (60.5)

660 (57.9)

0.047*

  Induction of labour

666 (27.5)

211 (24.3)

115 (27.7)

340 (29.8)

  No labour

286 (11.8)

97 (11.2)

49 (11.8)

140 (12.3)

 Exercise and active living in pregnancy

2908

0.001*

 Frequency of exercise/week

  0 to 2 times

1620 (55.7)

554 (53.0)

262 (51.3)

804 (59.5)

  3 or more times

1288 (44.3)

491 (47.0)

294 (48.7)

548 (40.5)

 Comparison to frequency of exercise/week prior to pregnancy

2909

<0.001*

  Less often

1774 (61.0)

634 (60.7)

264 (51.7)

876 (64.7)

  More often

178 (6.1)

59 (5.6)

30 (5.9)

89 (6.6)

  About the same

957 (32.9)

352 (33.7)

217 (42.5)

388 (28.7)

  Smoking

2701

302 (11.2)

101 (10.3)

38 (8.0)

163 (13.1)

0.006*

  Alcohol consumption

2704

1331 (49.2)

500 (51.1)

213 (44.7)

618 (49.5)

0.075

  Recreational drugs use

2905

112 (3.9)

33 (3.2)

11 (2.2)

68 (5.0)

0.006*