Nomogram for predicting PTB
The regression coefficients (B) from the multivariate analysis were used
to construct models to estimate the risk of PTB. The scoring model of
PTB < 37 weeks was as follows: 1.471+0.692*(BMI before
pregnancy=1) +0.953*(BMI before pregnancy=2) +2.370*(autoimmune
disease=1) +2.050*(History of PTB=1) +0.677*(Twin pregnancy=1)
+0.804*(IVF-ET=1)-0.048*Gestational age of 1st short
cervix-0.097*CL of 1st short cervix. (Figure
3A) The scoring model of PTB < 34 weeks was as follows:
3.072+1.781*(History of PTB=1) +1.125*(Twin pregnancy=1)
+1.539*(Prepregancy hypertension=1) -1.103*Gestational age of
1st short cervix-0.125*CL of 1stshort cervix. (Figure 3B)