During pregnancy PTB rate(%) Preterm Full-term Unadjusted Unadjusted Adjusted Adjusted
(n) (n) OR 95%CI OR 95%CI
Exercise
No 5.37 103 36.14 1.00 1.00
Yes 3.97 182 63.86 0.73* 0.57-0.94 0.74* 0.58-0.95
Time spent on exercise per week
None and low 5.28 112 39.30 1.00 1.00
Moderate 3.79 125 43.86 0.71* 0.54-0.92 0.72* 0.55-0.94
High 4.44 48 16.84 0.83 0.59-1.17 0.82 0.58-1.16
Energy expenditure per week
None and low 4.99 145 50.88 1.00 1.00
Moderate 3.76 113 39.65 0.74* 0.58-0.95 0.75* 0.58-0.96
High 4.58 27 9.47 0.91 0.59-1.37 0.89 0.57-1.33
Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001 Adjusted for maternal age, maternal occupation, parity, and family income. * P < 0.05, ** P <0.01, *** P <0.001