Table 2 Comparison of risks of adverse maternal outcomes between Asians and Caucasians, Ontario, Canada, April 1^st, 2015-March 31^st, 2017 (N = 69,734)

Gestational diabetes

9793

13.38

9077

5.53

2.71 (2.68, 2.74)

1.00 (0.97, 1.03)

Gestational hypertension

2012

2.75

6461

3.94

0.93 (0.88, 0.98)

−0.07 (− 0.12, − 0.02)

Preeclampsia

1945

2.66

7045

4.29

0.84 (0.78, 0.89)

−0.18 (− 0.23, − 0.13)

Placental previa

700

0.96

1097

0.67

1.30 (1.21, 1.40)

0.26 (0.17, 0.36)

Preterm birth (< 37 weeks)

5070

6.93

10,419

6.35

1.23 (1.20, 1.27)

0.21 (0.17, 0.24)

Preterm birth (< 34 weeks)

1376

1.88

2603

1.59

1.37 (1.29, 1.44)

0.31 (0.24, 0.38)

Preterm birth (< 32 weeks)

901

1.23

1582

0.96

1.49 (1.39, 1.58)

0.40 (0.30, 0.49)

Spontaneous preterm birth

1994

2.72

4103

2.50

1.25 (1.20, 1.31)

0.23 (0.17, 0.28)

Cesarean section

21,694

29.64

46,416

28.30

1.03 (1.01, 1.05)

0.03 (0.01, 0.05)

 Elective cesarean section

11,542

15.77

24,968

15.22

0.91 (0.89, 0.94)

−0.09 (−0.11, −0.07)

 Emergency cesarean section

10,146

13.86

21,443

13.07

1.22 (1.20, 1.25)

0.20 (0.18, 0.22)

Assisted vaginal delivery

8521

11.64

14,601

8.90

1.29 (1.26, 1.31)

0.25 (0.23, 0.28)

Episiotomy

10,443

14.27

14,552

8.87

1.40 (1.38, 1.43)

0.34 (0.31, 0.36)

3^rd and 4^th degree perineal tears

2756

4.19

3836

2.65

1.57 (1.52, 1.62)

0.45 (0.40, 0.50)