Table 4

Univariate analysis of birth length and sociodemographic characteristics—full term singleton female births, 1908 and 1914 cohorts excluded

CharacteristicNumberBirth length (cm)p value
mean (SD)95% CI
Delivery site
 Home21950.9 (2.9)50.5, 51.30.001*
 Hospital41150.0 (1.9)49.9, 50.2
Maternal marital status
 Unmarried8249.9 (2.5)49.3, 50.40.10*
 Married56350.4 (2.3)50.2, 50.6
Maternal age
 <202750.1 (1.3)49.6, 50.60.01
 20–2416450.0 (2.1)49.7, 50.3
 25–2918350.2 (2.1)49.9, 50.5
 30–3415050.4 (2.4)50.0, 50.8
 >3512150.8 (2.7)50.3, 51.3
Maternal parity
 025549.8 (2.2)49.5, 50.10.001
 115150.6 (1.9)50.3, 50.9
 2–314850.6 (2.1)50.3, 51.0
 4+9150.8 (3.2)50.1, 51.5
Parental social group
 11950.6 (1.8)49.7, 51.50.05 §
 25050.5 (2.2)49.9, 51.1
 311050.9 (2.1)50.5, 51.3
 421950.1 (2.3)49.8, 50.5
 522850.2 (2.2)49.9, 50.5
 missing1949.5 (4.0)47.6, 51.4
  • 95% CI = 95% confidence intervals, *two samplet test, test for trend (as continuous variable), Spearman trend test, §missing values not included in trend test.