Table 3 Unadjusted and adjusted odds ratios for the risk of gestational diabetes

Exposure period

 Pre-COVID-19

Reference

 COVID-19 Year 1

1.11 (1.02, 1.21)

0.02

1.05 (0.96, 1.15)

0.33

 COVID-19 Year 2

1.34 (1.23, 1.46)

 < 0.001

1.17 (1.06, 1.28)

0.01

Rate of 1^st and 2^nd trimester gestational weight gain (kg/week)

1.07 (0.95, 1.21)

0.3

1.31 (1.15, 1.49)

 < 0.001

Maternal age at conception

 < 20 years

0.34 (0.20, 0.56)

 < 0.001

0.39 (0.23, 0.66)

 < 0.001

 20–24.9 years

0.49 (0.41, 0.59)

 < 0.001

0.54 (0.44, 0.65)

 < 0.001

 25–34.9 years

Reference

 35–39.9 years

1.64 (1.52, 1.78)

 < 0.001

1.57 (1.44, 1.71)

 < 0.001

 40 years and over

1.96 (1.66, 2.32)

 < 0.001

1.92 (1.59, 2.31)

 < 0.001

Pre-pregnancy BMI category^b

 Underweight

0.79 (0.64, 0.97)

0.03

0.84 (0.68, 1.05)

0.12

 Healthy weight

Reference

 Overweight

1.59 (1.46, 1.72)

 < 0.001

1.61 (1.48, 1.76)

 < 0.001

 Obese

1.86 (1.70, 2.05)

 < 0.001

2.10 (1.89, 2.33)

 < 0.001

Ethnicity

 Caucasian

Reference

 South Asian

2.27 (2.02, 2.55)

 < 0.001

2.24 (1.98, 2.53)

 < 0.001

 Middle Eastern

1.54 (1.36, 1.73)

 < 0.001

1.50 (1.32, 1.70)

 < 0.001

 East and Southeast Asian

1.95 (1.70, 2.23)

 < 0.001

2.14 (1.85, 2.47)

 < 0.001

 Aboriginal and Torres Strait Islander

1.42 (1.04, 1.94)

0.03

1.47 (1.05, 2.05)

0.03

Socioeconomic disadvantage: SEIFA quintile^c

 Q1 (most disadvantaged)

1.20 (1.05, 1.38)

0.01

1.31 (1.13, 1.51)

 < 0.001

 Q2

1.16 (1.02, 1.320

0.02

1.06 (0.92, 1.22)

0.41

 Q3

1.10 (0.95, 1.270

0.21

1.01 (0.87, 1.18)

0.88

 Q4

0.99 (0.85, 1.16)

0.90

0.85 (0.72, 1.00)

0.05

 Q5 (least disadvantaged)

Reference

Nulliparity

0.98 (0.92, 1.06)

0.66

1.60 (1.48, 1.74)

 < 0.001

Prior history of gestational diabetes

6.25 (5.54, 7.06)

 < 0.001

6.05 (5.28, 6.92)

 < 0.001

First degree family member or sister with diabetes

1.73 (1.62, 1.86)

 < 0.001

1.40 (1.29, 1.50)

 < 0.001

Polycystic ovarian syndrome

1.60 (1.41, 1.83)

 < 0.001

1.33 (1.15, 1.53)

 < 0.001