The primary objective of this study is to determine whether there are markers in the tissue of atonic uteri, and in the patients' plasma that would help identify patients likely to suffer postpartum hemorrhage due to uterine atony. We also will attempt to identify the cause(s) of uterine atony that might suggest mechanisms to prevent and manage it.

Patient will be recruited from those admitted to our Labor and Delivery unit. Ten women will be the control subjects, and these will be selected from patients who are admitted for scheduled cesarean delivery. Ten women will be selected from women who develop uterine atony either following cesarean delivery, or postpartum patients who delivered vaginally but subsequently required surgical management of uterine atony (hysterectomy or uterine saving surgery). From each patient a small amount of uterine muscle will be excised and placed in a fixative, preservative transport medium. Ten cubic centimeters of blood will be drawn from each patient to accompany the tissue. The tissue and blood will be processed and analyzed to identify differences in the tissue and plasma of messenger RNA, micro RNA, long non-coding RNA, and DNA methylation in normal and atonic uterine patients. Statistical analysis of these markers will be performed to determine whether there are significant differences in their expression. It is hoped that differences will be discovered that may be used diagnostically to predict uterine atony, and differences that may suggest the etiology of uterine atony.

Inclusion Criteria:

• 18 years of age or older
• female
• pregnancy over 23 weeks gestation

Exclusion Criteria:

• under 18 years of age
• prisoners
• non-female sex
• cannot provide informed consent

Our study is to examine genomic markers in uterine atony, thus our subjects must have a uterus.

Patients recruited for the study will be pregnant women, 18 years of age or older who are laboring in Labor and Delivery, or who plan to have a scheduled cesarean section.