ID number
Strata indicator 1-6
Adjusted sampling weight
Scaled sampling weight
?
Answer questionnaire
0=single, 1=married
Mother's age in years
Race: 1=black, 0=white/other
High blood pressure: 1=yes,0=no
Vaginal bleeding: 1=yes, 0=no
Previous miscarriage:1=yes,0=no
Sex of child
Multiple birth: 1=yes, 0=no
Birthweight in grams
Birth weight groups
Birth weight < 1500 g
Birth weight < 2500 g
Age groups 1-5
Age < 20
Age < 25
Age 25-34
Age 35+