Table 2—

Factors associated with spontaneous and/or indicated preterm delivery

Spontaneous preterm delivery
Indicated preterm delivery
OR95% CIPOR95% CIP
Age >35 vs. 25–35 years1.90.4–8.20.410.80.2–3.30.73
Age <25 vs. 25–35 years7.71.6–36.60.010.40.1–5.50.52
Ethnicity, caucasian0.80.2–4.00.77
Social class, white collar2.60.8–8.10.111.40.6–3.20.39
Marital status, married2.20.2–21.40.50
Smoking0.60.1–5.40.680.80.2–3.60.80
Nulliparous1.50.5–4.60.444.91.6–14.70.005
Previous preterm delivery2.20.6–8.10.250.80.2–4.10.81
BMI1.00.8–1.20.800.90.8–1.10.53
Duration of diabetes1.00.9–1.10.651.00.9–1.00.55
Retinopathy0.70.2–2.30.581.60.7–3.70.31
Nephropathy1.60.3–8.30.602.80.8–9.90.10
Chronic hypertension2.10.2–20.70.526.31.7–23.10.006
Preconception care0.50.2–1.40.181.30.5–3.60.55
Progression of retinopathy1.40.2–12.10.784.11.2–14.00.03
Progression of nephropathy6.61.7–25.60.006
First trimester HbA1c1.30.9–1.80.121.30.9–1.80.18
HbA1c at delivery2.01.2–3.30.011.81.1–3.10.03
Preeclampsia18.97.0–51.5<0.001
Urogenital infection1.60.2–14.70.692.10.4–11.60.42
Polyhydramnios6.21.8–21.70.0041.20.4–3.60.73
  • Results of the univariate analysis are expressed as OR and its 95% CI vs. reference group (term delivery).