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Table 4 Association between maternal systemic/localized comorbidity and preterm birth according to clinical subtype and gestational age*

From: Association between maternal comorbidity and preterm birth by severity and clinical subtype: retrospective cohort study

 

Medically indicated

   PPROM

   Spontaneous

 

< 28 wk

28-31 wk

32-36 wk

   < 28 wk

28-31 wk

32-36 wk

   < 28 wk

28-31 wk

32-36 wk

Systemic comorbidity

         

   Hypertension

         

Preeclampsia/eclampsia

17.6 (15.4-20.1)

38.7 (35.6-42.1)

18.5 (17.8-19.1)

   0.2 (0.1-0.5)

0.6 (0.4-0.9)

0.9 (0.8-1.0)

   0.3 (0.2-0.5)

0.7 (0.5-1.1)

1.1 (1.0-1.2)

Pre-existing

3.4 (2.1-5.4)

6.7 (5.1-8.8)

5.1 (4.6-5.6)

   1.3 (0.7-2.3)

1.2 (0.7-2.0)

1.1 (0.9-1.3)

   1.0 (0.5-1.7)

0.9 (0.5-1.9)

0.9 (0.8-1.1)

Gestational

1.1 (0.5-2.0)

2.1 (1.4-3.1)

2.8 (2.5-3.1)

   0.1 (0.0-0.6)

0.5 (0.2-0.9)

0.6 (0.5-0.7)

   0.2 (0.1-0.6)

0.1 (0.0-0.5)

0.6 (0.5-0.7)

   Cardiovascular disease

2.2 (1.2-4.3)

3.4 (2.3-4.9)

3.0 (2.6-3.4)

   1.6 (0.8-3.4)

2.4 (1.5-4.0)

1.3 (1.0-1.6)

   1.6 (0.8-2.9)

2.0 (1.1-3.7)

1.1 (0.9-1.3)

   Diabetes

         

Pre-existing

1.2 (0.8-1.9)

3.2 (2.6-3.9)

3.9 (3.6-4.2)

   1.2 (0.8-1.8)

3.5 (2.8-4.4)

2.0 (1.9-2.2)

   0.9 (0.6-1.4)

2.2 (1.7-3.1)

1.4 (1.3-1.6)

Gestational

0.6 (0.4-0.8)

1.2 (1.0-1.4)

1.7 (1.6-1.8)

   0.5 (0.3-0.7)

1.3 (1.0-1.6)

1.5 (1.4-1.6)

   0.3 (0.2-0.4)

0.8 (0.6-1.1)

1.3 (1.3-1.4)

   Edema/renal disease

6.8 (4.4-10.3)

11.9 (9.4-14.9)

7.3 (6.6-8.1)

   1.4 (0.6-3.3)

1.7 (0.9-3.3)

1.1 (0.8-1.4)

   1.8 (1.0-3.4)

0.9 (0.3-2.4)

1.1 (0.9-1.4)

   Genitourinary infection

1.7 (1.3-2.3)

2.6 (2.2-3.1)

1.8 (1.7-1.9)

   2.1 (1.6-2.7)

2.6 (2.1-3.1)

1.2 (1.1-1.3)

   1.3 (1.0-1.7)

1.0 (0.7-1.4)

1.0 (0.9-1.1)

   General infection

2.5 (1.8-3.5)

2.2 (1.7-2.8)

2.2 (2.0-2.4)

   3.0 (2.3-4.0)

2.8 (2.2-3.6)

1.4 (1.2-1.5)

   1.7 (1.3-2.4)

2.1 (1.5-2.9)

1.3 (1.2-1.4)

   Thyroid disease

2.3 (1.6-3.4)

2.1 (1.6-2.8)

1.9 (1.7-2.1)

   1.9 (1.3-2.9)

1.9 (1.3-2.6)

1.3 (1.2-1.5)

   1.1 (0.7-1.7)

1.6 (1.0-2.5)

1.1 (1.0-1.2)

   Anemia

2.2 (1.9-2.6)

2.7 (2.4-2.9)

1.6 (1.5-1.7)

   2.1 (1.8-2.4)

1.7 (1.5-1.9)

0.9 (0.9-0.9)

   1.3 (1.2-1.5)

1.0 (0.8-1.2)

0.7 (0.7-0.8)

   Drug dependence

1.8 (0.8-4.4)

5.1 (3.5-7.5)

3.3 (2.8-3.9)

   5.9 (3.7-9.3)

4.9 (3.2-7.4)

3.3 (2.8-3.9)

   3.9 (2.4-6.2)

6.1 (4.0-9.2)

4.1 (3.6-4.6)

   Mental disorders

3.6 (2.5-5.3)

2.6 (1.9-3.6)

2.4 (2.1-2.7)

   3.3 (2.2-4.8)

4.1 (3.0-5.5)

1.9 (1.7-2.2)

   2.7 (1.9-3.8)

2.6 (1.7-3.9)

1.8 (1.6-2.0)

Localized comorbidity

         

   Hemorrhage

         

Placental abruption

27.7 (24.2-31.8)

25.2 (22.9-27.9)

10.7 (10.2-11.3)

   24.7 (21.6-28.2)

19.7 (17.5-22.2)

3.0 (2.8-3.2)

   30.4 (27.4-33.7)

28.4 (25.3-31.8)

5.1 (4.9-5.4)

Placenta previa

17.7 (12.9-24.2)

30.4 (25.6-36.1)

29.8 (27.9-31.8)

   16.8 (12.5-22.7)

6.6 (4.5-9.6)

2.1 (1.8-2.5)

   3.4 (2.0-5.9)

3.0 (1.5-5.7)

0.8 (0.6-1.0)

   Chorioamnionitis

3.8 (3.3-4.5)

1.5 (1.3-1.8)

0.9 (0.9-1.0)

   24.0 (21.5-26.8)

12.4 (11.2-13.6)

2.0 (1.9-2.1)

   9.6 (8.7-10.6)

4.5 (3.9-5.2)

1.0 (1.0-1.1)

   Amniotic sac

         

Polyhydramnios

3.1 (2.0-4.7)

5.1 (4.0-6.5)

3.6 (3.3-4.0)

   1.7 (1.0-3.0)

2.4 (1.6-3.5)

1.3 (1.1-1.5)

   2.1 (1.4-3.1)

4.1 (3.0-5.6)

1.6 (1.5-1.8)

Oligohydramnios

10.2 (8.4-12.4)

13.0 (11.5-14.8)

8.6 (8.1-9.1)

   15.1 (12.8-17.8)

12.6 (10.9-14.6)

2.2 (2.0-2.4)

   2.6 (2.0-3.5)

1.7 (1.1-2.5)

0.8 (0.7-0.9)

   Cervical incompetence

68.6 (54.6-86.1)

13.6 (9.8-18.9)

7.1 (6.1-8.4)

   123 (103-146)

33.4 (26.1-42.7)

6.1 (5.1-7.2)

   159 (139-183)

32.4 (24.5-42.9)

6.9 (5.9-7.9)

   Structural abnormality

6.8 (5.5-8.3)

6.3 (5.4-7.3)

3.5 (3.2-3.7)

   4.2 (3.3-5.2)

4.2 (3.4-5.1)

2.0 (1.9-2.2)

   2.5 (2.0-3.2)

2.2 (1.6-2.9)

0.8 (0.7-0.9)

   Previous cesarean delivery

1.2 (1.0-1.4)

1.3 (1.1-1.4)

2.0 (2.0-2.1)

   1.1 (0.9-1.3)

0.9 (0.7-1.0)

0.8 (0.7-0.8)

   0.4 (0.3-0.5)

0.5 (0.4-0.6)

0.4 (0.4-0.4)

   Fetal anomaly

159 (123-204)

16.3 (10.2-26.2)

12.4 (10.1-15.3)

   3.2 (0.8-12.8)

7.0 (3.1-15.6)

2.3 (1.5-3.5)

   142 (115-176)

8.7 (3.9-19.6)

4.1 (3.1-5.5)

  1. * Odds ratio (95% confidence interval) adjusted for maternal age, grand multiparity, and period (rounded to the first decimal to conserve space)
  2. † Preterm premature rupture of membranes
  3. ‡ Spontaneous preterm labour before 37 weeks of gestation with intact membranes