This retrospective review will will attempt to determine whether our data show a significant difference in number of deliveries of women with pre-eclampsia compared to deliveries without pre-eclampsia during certain months of the year.

This study is a retrospective review of obstetrics charts of women who gave birth at OSU Medical Center between January 01, 2005 and December 31, 2007.

Included will be patient charts of women > 18 years old who were admitted to OSUMC for delivery (both cesarean and vaginal deliveries) between 1/1/05 and 12/31/07, with and without a diagnosis of pre-eclampsia. The data collected will be recorded in a spreadsheet by month/day of delivery, and whether pre-eclampsia was a diagnosis. Also included will be total number of deliveries per month and total number of pre-eclampsia diagnoses per month. The rate of pre-eclampsia will be calculated.

A contingency table with corresponding chi square test will be performed to determine whether there is a significant relationship of the diagnosis of pre-eclampsia with seasonality, defined primarily by month. Certain data occurring during transition periods between seasons may be excluded from analyses.

Inclusion Criteria:

• Women who gave birth at OSU Medical Center between January 01, 2005 and December 31, 2007 and were > 18 years old who were admitted to OSUMC for delivery (both cesarean and vaginal deliveries) between 1/1/05 and 12/31/07, with and without a diagnosis of pre-eclampsia.

Exclusion Criteria:

• Females under age 18

Women of all races who were admitted to OSUMC for delivery of a baby (both cesarean and vaginal deliveries) between 1/1/05 and 12/31/07, with or without a diagnosis of pre-eclampsia.