Table 3 Univariable and multivariable logistic regression analysis of variables potentially associated with sPTB recurrence (n = 66).

From: Optimal annual body mass index change for preventing spontaneous preterm birth in a subsequent pregnancy

  

sPTB recurrence

Non-recurrence

p-value

sPTB recurrence

cOR

95%CI

aOR

95%CI

n = 16

n = 50

Index-pregnancy

Maternal age ≥ 35 years

5 (31.3)

11 (22.0)

0.509

3.3

(0.2–55.4)

1.7

(0.3–8.3)

Maternal age < 20 years

1 (6.3)

1 (2.0)

0.429

1.6

(0.5–5.6)

2.1

(0.1–41.1)

Pre-pregnancy BMI < 18.5 kg/m2

7 (43.8)

13 (26.0)

0.217

2.2

(0.7–7.2)

1.9

(0.5–8.1)

Inter-pregnancy

Pregnancy interval, years

2.8 ± 1.5

2.1 ± 0.7

0.060

2.3*

(1.1–4.6)

2.2

(1.0–4.8)

Anuual BMI change, kg/m2/year

− 0.15 ± 0.81

0.34 ± 0.91

0.056

0.5

(0.3–1.1)

0.4*

(0.2–1.0)

Subsequent-pregnancy

Gestational weight gain, kg

8.1 ± 3.5

9.6 ± 3.3

0.131

0.9

(0.7–1.1)

0.9

(0.7–1.1)

  1. cOR, clude odds ratio; aOR, adjusted OR; CI, confidence interval; BMI, body mass index; sPTB, spontaneous preterm birth.
  2. *Statistically significant.