Why are the calculated gestational age data different from previous versions of VistaPHw?
In previous data files (issued before 2006), if the menses month and/or year were missing or the calculated gestational age was beyond a reasonable range (<18 or >45 weeks), the gestational age was estimated from the child’s birth weight. Currently, if the gestational age cannot be calculated because of missing menses dates or the calculated age is out of range, the clinical estimate is used. If the clinical estimate is also out of range or unknown, the calculated age is unknown. For 1980-88, the birth certificate did not collect the clinical estimate. For these years, only the gestational age calculated from the menses date is included in this field. In all other cases, the calculated age is unknown. This change makes the Washington State data consistent with data published by the National Center for Health Statistics (NCHS). • Why is maternal smoking by trimester and BMI only available after 2003? Maternal smoking by trimester and BMI were added to the 2003 revised birth certificate.
