Previous Preterm Birth and Current Maternal Complications as a Risk Factor of Subsequent Stillbirth

Table 3

Adjusted odd ratios from logistic regression analysis for prediction of stillbirth by maternal risk factors.

Predictor variables	OR (95% CI)^b; Singletons	OR (95% CI)^b; Twins
Previous preterm	1.63 (1.41–1.88)	1.75 (1.20–2.56)
No previous preterm	1.00	1.00
Eclampsia present	2.45 (1.41–4.25)	0.96 (0.13–7.00)
Eclampsia absent	1.00	1.00
Insulin-dependent diabetes	1.74 (1.38–2.19)	0.67 (0.27–1.63)
No insulin	1.00	1.00
Hydramnios/oligohydramnios	2.28 (1.99–2.62)	4.72 (3.70–6.02)
No hydramnios	1.00	1.00
Chronic hypertension	2.04 (1.70–2.45)	1.25 (0.70–2.25)
No chronic hypertension	1.00	1.00
Uterine bleeding	5.89 (5.13–6.76)	4.19 (2.75–6.38)
No uterine bleeding	1.00	1.00
Black	2.10 (1.99–2.22)	1.51 (1.27–1.79)
White	1.00	1.00
No smoking	0.64 (0.61–0.68)	1.01 (0.83–1.22)
Smoking	1.00	1.00
Maternal education level < 12 years	1.00	1.00
Maternal education level ≥ 12 years	0.93 (0.88–0.99)	0.66 (0.54–0.80)
Maternal age < 18 years	1.30 (1.17–1.44)	1.01 (0.66–1.55)
Maternal age 18–35 years	1.00	1.00
Maternal age > 35 years	1.66 (1.54–1.80)	1.36 (1.08–1.71)

Model included all maternal sociodemographic factors and pregnancy and labor complications examined in this study, including marital status, maternal age, prenatal smoking, number of fetuses born, maternal educational level, maternal race, previous preterm and small for gestational age births, uterine bleeding, eclampsia, preeclampsia, placenta previa, placental abruption, chronic hypertension, insulin-dependent diabetes and other forms of diabetes, acute/chronic lung disease, genital herpes, hydramnios/oligohydramnios, renal disease, and anemia. Only those variables with significant findings in our analysis are presented in this table.
^bOR = odd ratios, 95% CI = 95% confidence intervals.