Table 1

Clinical and demographical characteristics

Cases (n = 196)

Controls (n = 211)

p


Maternal age (years)

29 [20-34]

30 [21-34]

0.135

Gestational age (days)

253 [172-258]

280 [273-286]

< 0.001

Primiparity

128 (65.3%)

98 (46.4%)

< 0.001

Smoking wk 1-17 of pregnancy (%)

64 (32.7%)

55 (26.1%)

0.124

Pre-pregnancy BMI

23.03 [14.84-41.26]

23.23 [17.30-38.10]

0.561

Birth weight (g)

2815 [747-4000]

3645 [2610-4970]

< 0.001

Gender infant, male

51.5%

42.7%

0.073

Paternal age (years)

31 [20-46]

31 [23-48]

0.561

Previous PTD

18 (9.2%)

3 (1.4%)

< 0.001

Gestational bleeding, 2nd trimester

28 (15.8%)

21 (10.9%)

0.161


1 Medians are reported with the range in brackets.

2 Cases are defined as preterm delivery < 37 weeks of gestation, while controls are defined as term delivery from 39+0 to 40+6 weeks of gestation.

3 P-values are calculated by Mann-Whitney U test for continuous variables and chi-square test for categorical variables.

4 Information about pre-pregnancy BMI and smoking in week 1-17 of pregnancy is self reported and collected from MoBa Questionnaire 1.

Myking et al. BMC Medical Genetics 2011 12:174   doi:10.1186/1471-2350-12-174

Open Data