| Field name             | Type    | Mode     | Description|
|------------------------|---------|----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| source_year            | INTEGER | REQUIRED | Four-digit year of the birth. Example: 1975.|
| year                   | INTEGER | NULLABLE | Four-digit year of the birth. Example: 1975.|
| month                  | INTEGER | NULLABLE | Month index of the date of birth, where 1=January.|
| day                    | INTEGER | NULLABLE | Day of birth, starting from 1.|
| wday                   | INTEGER | NULLABLE | Day of the week, where 1 is Sunday and 7 is Saturday.|
| state                  | STRING  | NULLABLE | The two character postal code for the state. Entries after 2004 do not include this value.|
| is_male                | BOOLEAN | REQUIRED | TRUE if the child is male, FALSE if female.|
| child_race             | INTEGER | NULLABLE | The race of the child. One of the following numbers: 1 - White 2 - Black 3 - American Indian 4 - Chinese 5 - Japanese 6 - Hawaiian 7 - Filipino 9 - Unknown/Other 18 - Asian Indian 28 - Korean 39 - Samoan 48 - Vietnamese |
| weight_pounds          | FLOAT   | NULLABLE | Weight of the child, in pounds.|
| plurality              | INTEGER | NULLABLE | How many children were born as a result of this pregnancy. twins=2, triplets=3, and so on.| 
| apgar_1min             | INTEGER | NULLABLE | Apgar scores measure the health of a newborn child on a scale from 0-10. Value after 1 minute. Available from 1978-2002.|
| apgar_5min             | INTEGER | NULLABLE | Apgar scores measure the health of a newborn child on a scale from 0-10. Value after 5 minutes. Available from 1978-2002.|
| mother_residence_state | STRING  | NULLABLE | The two-letter postal code of the mother's state of residence when the child was born.|
| mother_race            | INTEGER | NULLABLE | Race of the mother. Same values as child_race.|
| mother_age             | INTEGER | NULLABLE | Reported age of the mother when giving birth.|
| gestation_weeks        | INTEGER | NULLABLE | The number of weeks of the pregnancy.|
| lmp                    | STRING  | NULLABLE | Date of the last menstrual period in the format MMDDYYYY. Unknown values are recorded as "99" or "9999".|
| mother_married         | BOOLEAN | NULLABLE | True if the mother was married when she gave birth.|
| mother_birth_state     | STRING  | NULLABLE | The two-letter postal code of the mother's birth state.|
| cigarette_use          | BOOLEAN | NULLABLE | True if the mother smoked cigarettes. Available starting 2003.|
| cigarettes_per_day     | INTEGER | NULLABLE | Number of cigarettes smoked by the mother per day. Available starting 2003.|
| alcohol_use            | BOOLEAN | NULLABLE | True if the mother used alcohol. Available starting 1989.|
| drinks_per_week        | INTEGER | NULLABLE | Number of drinks per week consumed by the mother. Available starting 1989.|
| weight_gain_pounds     | INTEGER | NULLABLE | Number of pounds gained by the mother during pregnancy.|
| born_alive_alive       | INTEGER | NULLABLE | Number of children previously born to the mother who are now living.|
| born_alive_dead        | INTEGER | NULLABLE | Number of children previously born to the mother who are now dead.|
| born_dead              | INTEGER | NULLABLE | Number of children who were born dead (i.e. miscarriages)|
| ever_born              | INTEGER | NULLABLE | Total number of children to whom the woman has ever given birth (includes the current birth).|
| father_race            | INTEGER | NULLABLE | Race of the father. Same values as child_race.| 
| father_age             | INTEGER | NULLABLE | Age of the father when the child was born.|
| record_weight          | INTEGER | NULLABLE | 1 or 2, where 1 is a row from a full-reporting area, and 2 is a row from a 50% sample area. |