Coagulation Factor Changes Associated With Postpartum Hysterectomies

Completed

Conditions: Obstetric Labor Complications
Hemorrhage
Complications; Cesarean Section

Interventions: Procedure: Blood Draw

Registration Number: NCT00456547

Lead Sponsor: Northwestern University

Brief Summary: The purpose of this study is to examine components of the coagulation system in women undergoing postpartum hysterectomy and to compare laboratory parameters of coagulation in these women to women at increased risk for a postpartum hysterectomy, but who do not have postpartum hemorrhage and a postpartum hysterectomy. During normal pregnancy, the hemostatic balance tips toward hypercoagulation. Non-obstetric surgical blood loss is associated with increased coagulation activity. We have observed that women undergoing a postpartum hysterectomy become hypocoagulable secondary to a consumptive coagulopathy and/or excessive fibrinolysis. This coagulopathy may lead to the administration of multiple blood products. Worldwide, postpartum hemorrhage is a leading cause of maternal death. Plasma levels of tissue plasminogen activator, urokinase plasminogen activator and their inhibitors increase during pregnancy. During labor and delivery activation of coagulation occurs with consumption of platelets, coagulation factors and inhibitors. Obstetric complications during delivery can excessively activate the coagulation system and disseminated intravascular coagulation may ensue. Current treatment for postpartum coagulopathy is non-specific and primarily consists of replacing blood components. If specific causes or markers of abnormal coagulation can be identified in women at risk, then it might be possible to target (with specific medications) specific abnormalities early in the process and decrease hemorrhage and the need for blood transfusions.

Detailed Description: All women scheduled for a Cesarean-hysterectomy will be asked to enroll in the study, as well as the women with the following diagnoses, which puts them at increased risk for Cesarean hysterectomy: placenta previa, placenta accreta, vaginal trial of labor after a previous Cesarean delivery.

Written, informed consent will be obtained from all subjects. A blood sample will be obtained shortly after admission to the hospital. In women who go on to have a hysterectomy, blood samples will be obtained at predefined time periods (at time of decision to perform hysterectomy, with every clinically indicated blood draw for coagulation tests, 2 hours after delivery. The next patient at risk of Cesarean hysterectomy, but who does not go on to have a hysterectomy, will serve as a cohort control. Blood samples will be drawn at 2 hours after delivery for coagulation testing. Baseline samples from all other study subjects will be discarded and no further blood work will be obtained. The primary outcome will be the the level of fibrinogen at 2 hours following delivery as a marker of consumptive coagulopathy.

Every patient at risk for hemorrhage has at least one peripheral intravenous cannula inserted upon admission to the Labor \& Delivery Unit. A 2nd IV cannula is almost always placed, usually when the decision is made to proceed with a Cesarean delivery. All study subjects will have a 2nd IV cannula placed for drawing blood for study coagulation tests, and any other clinically indicated blood tests. The cannula will be connected to a stopcock with a "heparin lock" (cannula and stopcock are flushed with saline between aspirations) and left in place for 48 hours after delivery.

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 24

Inclusion Criteria

All women scheduled for a Cesarean-hysterectomy will be asked to enroll in the study, as well as the women with the following diagnoses, that puts them at increased risk for Cesarean hysterectomy: placenta previa, placenta accreta, vaginal trial of labor after previous Cesarean delivery.

Exclusion Criteria

Anyone who does not fit the above criteria.

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Postpartum hysterectomy	Blood Draw	Women that require postpartum hysterectomy for post-delivery bleeding.
Cesarean delivery case controls	Blood Draw	Women that deliver by cesarean that presented with risk factors for bleeding but did not require post delivery hysterectomy

Primary Outcome Measures

Name	Time	Method
Fibrinogen Level at 2 Hours After Delivery	2 hours after delivery	Fibrinogen level decrease is a marker of consumptive coagulation which is is a pathological activation of coagulation (blood clotting) mechanisms that happens in response to a variety of diseases or stimulus. We hypothesized that women with excessive bleeding following delivery who require a hysterectomy are more likely to exhibit lower levels of fibrinogen and a consumptive coagulopathy than women following cesarean delivery who do not bleed.

Secondary Outcome Measures

Name	Time	Method
Platelet Counts at 2 Hours After Delivery	2 hours after delivery	Platelets are decreased in subjects with consumptive coagulopathies which is a pathological activation of coagulation (blood clotting) mechanisms that happens in response to a variety of diseases. We hypothesized that women who require hysterectomy for postpartum bleeding are more likely to have decreased platelet counts than matched controls that underwent cesarean delivery.
Plasminogen Levels 2 Hours After Delivery	2 hours after delivery	Plasminogen is converted to plasmin when the coagulation system is activated. We hypothesized that plasminogen should be decrease more in women with continued bleeding following delivery requiring hysterectomy will demonstrated a greater decrease in plasminogen than following cesarean delivery.
Antithrombin III Levels at 2 Hours Post Delivery	2 hours after delivery	Antithrombin III is a glycoprotein and is the major inhibitor of thrombin and other activated clotting factors, including factors IX, X, XI, and XII, the cofactor through which heparin exerts its effect. We hypothesized that women with continued bleed following delivery and require a hysterectomy will demonstrate a greater reduction in antithrombin III that women undergoing cesarean delivery.