Table 2 Multivariable hazard ratios (HR) and 95% confidence intervals (CI) of incident T2DM by number of parity until phase VI (2015–2018): Tehran Lipid and Glucose Study

Parity (continuous variable)

Per each additional

557/2552

1.10 (1.05–1.16)

< 0.001

1.10 (1.04–1.15)

< 0.001

1.09 (1.04–1.15)

1.05 (1.00–1.11)

1.04 (0.99–1.10)

Number of parity

1

19/180

1

1

1

1

1

2

99/614

1.48 (0.90–2.41)

0.121

1.48 (0.91–2.43)

0.116

1.48 (0.90–2.42)

1.41 (0.86–2.31)

1.39 (0.85–2.27)

3

128/640

1.74 (1.07–2.83)

0.025

1.75 (1.07–2.86)

0.025

1.73 (1.06–2.83)

1.54 (0.94–2.52)

1.50 (0.92–2.45)

≥ 4

311/1118

2.28 (1.40–3.70)

0.001

2.27 (1.39–3.72)

0.001

2.23 (1.36–3.65)

1.72 (1.05–2.83)

1.64 (1.00–2.70)

P value for trend

< 0.001

< 0.001