Categories	Cesarean section	Preterm birth	SGA	LGA	Combined risk
Underweight	Y=exp(−1.641 + 0.021 x)	Y=exp(−0.866 – 0.016 x)	Y=exp(−1.716 –0.050 x)	Y=exp(−3.066 + 0.054x)	Y = 0.000537x2 – 0.017247x + 0.481669
Normal	Y=exp(−1.169 + 0.027 x)	Y=exp(−1.759 – 0.092 x)	Y=exp(−2.523 –0.033 x)	Y=exp(−2.408 + 0.055x)	Y = 0.000519x2 – 0.009448x + 0.479481
Overweight	Y=exp(−0.646 + 0.033 x)	Y=exp(−1.873 – 0.048 x)	Y=exp(−2.758 –0.046 x)	Y=exp(−1.801 + 0.062x)	Y = 0.000091x2 + 0.004888x + 0.531713
Obese	Y=exp(−0.326 + 0.053 x)	Y=exp(−1.472 – 0.080 x)	Y=exp(−3.146 –0.017 x)	Y=exp(−1.236 + 0.037x)	Y = 0.000386x2 + 0.000068 x + 0.653351

SGA, small for gestational age; LGA, large for gestational age.