Thromboelastography to Assess Age-Related Coagulation Differences in Patients Undergoing Elective Cesarean Delivery.

The purpose of the study is to assess potential age-related differences on coagulation profile of patients undergoing Cesarean Section, using thromboelastography (TEG). The investigators will compare coagulation data collected from the study to assess potential differences in coagulation parameters for the following age groups: (i) women less than 35 yrs (ii) women 35 yrs or older. This study will allow us to collect more information about differences regarding coagulation profile in patients undergoing cesarean section who are less than 35 y vs. 35y or older. This information will add to current knowledge base about potential risk for thrombotic events according with age.

All obstetric patients presenting for elective Cesarean delivery (CD) will be informed about the study prior to and on admission to the labor and delivery unit. Patients will be informed at parents' education classes (during education sessions by obstetric anesthesiologists who are also members of the research team). Potential participants will be approached by a member of the research team prior to surgery. A study investigator will obtain patient written informed consent.

Pre-operatively, blood sampling will take place by venepuncture for the following analysis:

Hematocrit, Platelet count (which are part of standard of care), TEG, prothrombin time (PT), Partial Thromboplastin Time (PTT), International Normalized Ratio (INR), fibrinogen (for research purposes only, unless they are needed for clinical purposes).

The investigators would prefer to avoid taking blood samples from indwelling peripheral IV lines, as the samples will likely be diluted with intravenous fluid and therefore may significantly affect blood sampling analysis. The volumes of blood necessary for TEG analysis are extremely small (1 ml - less than half of a teaspoon - per TEG analysis; total =3 samples), and therefore will not significantly affect any potential degree of hemorrhage or total blood loss incurred. The volumes of blood for laboratory analysis will also be small (4-5 ml - about 1 teaspoon - for each research sample: total =3 samples), and will not affect overall blood loss. No randomization will be possible. TEG and laboratory samples will be taken at the following time intervals: prior to anesthesia in the preoperative holding unit, post-operative days one and three.