Prediction of Preterm Birth by Maternal Characteristics and Medical History in the Brazilian Population
Table 2
Odds Ratios and 95% confidence intervals obtained by univariate and multivariate logistic regression analysis for spontaneous preterm birth <34 weeks of gestational age (Hospital das Clínicas, Ribeirão Pretro, São Paulo, Brazil, 2016).
Independent variables
Univariate Analysis
Multivariate Analysis
OR
95% CI
value
OR
95% CI
value
Maternal age (years)
1.038
0.969–1.112
0.283
1.032
0.960–1.110
0.391
Maternal height (cm)
0.995
0.929–1.066
0.892
1.005
0.939–1.075
0.891
Use of ovulation‐inducing drugs
1.687
0.090–31.653
0.726
1.268
0.532–23.105
0.872
Ethnicity
Nonwhite
1.180
0.498–2.798
0.707
1.281
0.357–1.802
0.581
Smoking
4.382
1.788–10.738
0.001∗
3.744
1.500–9.344
0.005∗
Obstetric history
No previous pregnancy >16 w
1.255
0.475–3.321
0.647
2.779
0.760–10.156
0.122
Spontaneous PTB <37 w
4.110
1.172–14.410
0.027∗
3.962
1.078–14.564
0.038∗
Iatrogenic PTB <37 w
7.078
0.856–58.535
0.069
6.386
0.718–56.785
0.096
∗Significant at 0.05 level. OR: odds ratio; CI: confidence interval; PTB: preterm birth; w: weeks of gestation.