Table 1 Sample socio-demographic characteristics, maternal health behaviors, and childhood obesity and blood pressure outcomes of the singleton children from the existing CENTURY study and Linked CENTURY study (linked with each child’s Massachusetts birth certificate), 1980–2008
|  | CENTURY Study | Linked CENTURY Study | ||
|---|---|---|---|---|
Characteristics | Total N | % | Total N | % |
Any data at age ≤ 18 years | 269959 |  | 200343 |  |
 Any data at age < 2 years | 121389 | 45.0 % | 104584 | 52.2 % |
 Any data at age 5 years | 72195 | 26.7 % | 57547 | 28.7 % |
 Any data at age 11 years | 61270 | 22.7 % | 44812 | 22.4 % |
 Any data at age 17 years | 46559 | 17.2 % | 31326 | 15.6 % |
Race/ethnicity | Child’s race/ethnicity | Mother’s race/ethnicity | ||
 White | 121565 | 45.0 % | 151643 | 75.7 % |
 Black | 23906 | 8.9 % | 23144 | 11.6 % |
 Hispanic | 9018 | 3.3 % | 9123 | 4.6 % |
 Asian | 7941 | 2.9 % | 11421 | 5.7 % |
 Other | 11076 | 4.1 % | 2396 | 1.2 % |
 Missing | 96453 | 35.7 % | 2616 | 1.3 % |
Insurance | Medical insuranced | Delivery paymenta, e | ||
 Private | 73412 | 27.2 % | 136022 | 87.5 % |
 Medicaid | 18215 | 6.7 % | 17116 | 11.0 % |
 Other | - | - | 1960 | 1.3 % |
 Missing | 178332 | 66.1 % | 398 | 0.3 % |
Mother US born | Â | Â | Â | Â |
 No |  |  | 39972 | 20.0 % |
 Yes |  |  | 158965 | 79.4 % |
 Missing |  |  | 1406 | 0.7 % |
Mother married at time of birth | Â | Â | Â | Â |
 No |  |  | 31232 | 15.6 % |
 Yes |  |  | 169026 | 84.4 % |
 Missing |  |  | 85 | 0.0 % |
Mother smoked during pregnancyb | Â | Â | Â | Â |
 No |  |  | 109846 | 93.9 % |
 Yes |  |  | 6852 | 5.9 % |
 Missing |  |  | 264 | 0.2 % |
Mother had gestational diabetes mellitusc | Â | Â | Â | Â |
 No |  |  | 80953 | 96.1 % |
 Yes |  |  | 2884 | 3.4 % |
 Missing |  |  | 413 | 0.5 % |
Cesarean deliverya | Â | Â | Â | Â |
 No |  |  | 118439 | 76.2 % |
 Yes |  |  | 36256 | 23.3 % |
 Missing |  |  | 801 | 0.5 % |
Breastfeeding initiationa | Â | Â | Â | Â |
 No |  |  | 36097 | 23.2 % |
 Yes |  |  | 118638 | 76.3 % |
 Missing |  |  | 761 | 0.5 % |
Weight-for-length ≥ 95th percentile anytime between 1 and 24 months [69] | 27331 | 22.5 % | 23756 | 22.7 % |
BMI ≥ 95th percentile [53] |  |  |  |  |
 Age 5 years | 8566 | 11.9 % | 6934 | 12.0 % |
 Age 11 years | 9619 | 15.7 % | 7184 | 16.0 % |
 Age 17 years | 5566 | 12.0 % | 3758 | 12.0 % |
Systolic blood pressure z-score [55] | N | Mean (SD) | N | Mean (SD) |
 Age 5 years | 66391 | −0.19 (0.81) | 52997 | −0.20 (0.81) |
 Age 11 years | 57935 | 0.02 (0.89) | 42391 | 0.02 (0.89) |
 Age 17 years | 44652 | −0.11 (0.97) | 30078 | −0.11 (0.97) |
Diastolic blood pressure z-score [55] | N | Mean (SD) | N | Mean (SD) |
 Age 5 years | 66391 | 0.08 (0.71) | 52997 | 0.08 (0.71) |
 Age 11 years | 57935 | 0.17 (0.74) | 42391 | 0.17 (0.73) |
 Age 17 years | 44652 | 0.11 (0.75) | 30078 | 0.10 (0.74) |