Table 3

Univariate analysis of birth weight and sociodemographic characteristics—full term singleton female births, 1908 cohort excluded

CharacteristicNumberBirth weight (g)p value
mean (SD)95% CI
Delivery site
 Home3543683 (523)3628, 37380.001*
 Hospital4523371 (470)3327, 3414
Maternal marital status
 Unmarried1133339 (489)3247, 34300.001*
 Married7243535 (519)3497, 3573
Maternal age
 <20403411 (463)3263, 35590.001
 20–241953406 (534)3330, 3481
 25–292383527 (527)3460, 3594
 30–342033508 (481)3442, 3575
 >351613629 (525)3548, 3711
Maternal parity
 03253331 (499)3277, 33860.001
 11963575 (472)3508, 3641
 2–31933616 (538)3540, 3692
 4+1233701 (475)3717, 3786
Parental social group
 1353596 (503)3423, 37690.35 §
 2773462 (411)3368, 3555
 31493549 (505)3468, 3632
 42653501 (545)3435, 3567
 52873493 (538)3431, 3555
 missing243535 (409)3254, 3816
  • 95% CI = 95% confidence intervals, *two samplet test, test for trend (as continuous variable), Spearman trend test, §missing values not included in trend test.