Methods
We explored differences in outcomes between these diagnoses, and compared patterns in outcomes over time, focusing the following two study cycles: 1998-2000, and 2009-2011. We compared these patients to those without these diagnoses. We identified pregnancy hospitalizations that resulted in delivery, as well as pregnancy outcomes, using the appropriate ICD-9 and V codes. Statistical weighting of the data produced samples that were nationally representative. SAS software and chi-square testing was used to determine p-values.
