Continuous Non-Invasive Measurement of Hemoglobin During Parturition

Obstetric hemorrhage remains the leading cause of maternal death worldwide (2). The most
common culprits are uterine atony, placental disorders, and delivery trauma. Current
detection and management of hemorrhage is heavily based on clinical judgment and laboratory
results. Interventions such as fluid resuscitation and blood transfusion are often initiated
after a significant hemorrhage has already taken place. Early detection and treatment of this
potentially life threatening obstetric complication is of upmost importance in the field of
obstetrics. Traditional methods for assessing hemoglobin levels involve collecting the
patient's blood and sending it to the laboratory for analysis via complete blood count (CBC).
This involves a delay and often patients are continuing to hemorrhage while the CBC is being
processed. Novel technology has recently been approved by the FDA, which can continuously
assess hemoglobin levels via a non-invasive monitor. This device works as a pulse oximeter,
which is placed on the index finger and uses infrared technology to estimate hemoglobin
levels (1). Despite its validation and use in many patient populations such as trauma,
neurosurgery and orthopedic surgery, data is lacking in an obstetric population. The
investigator's hypothesis is that this device will enable clinicians detect hemorrhage early
and initiate resuscitation such as fluid and/or blood transfusion before significant
hemorrhage has taken place. This study will be a proof of concept prospective cohort study,
in which the investigators will attempt to detect the association between intra-operative and
postoperative continuous non-invasive hemoglobin monitoring and postpartum decrease in
hemoglobin.

Women undergoing primary cesarean delivery after failed induction of labor or repeat cesarean
delivery after failed TOLAC (trial of labor after cesarean delivery), will be eligible for
participation in this study. Prior to cesarean, all patients will have a CBC drawn. Masimo
non-invasive hemoglobin monitor will be placed on their finger during delivery and remain in
place until discharge from the recovery room. All patients will have CBC drawn on post
operative day 1, as is the standard of care at our institution. Based on the drop in
hemoglobin from pre-op to post-op day 1, patients will be separated into quartiles. The
quartile with the highest drop in hemoglobin will be the "cases" and compared to the
remainder of the quartiles or "controls." In addition, values obtained from the non-invasive
monitor will be compared to those obtained from CBC.

Inclusion Criteria:

- Pregnant women undergoing primary cesarean delivery after failed induction of labor,
or repeat cesarean delivery after failed TOLAC (trial of labor after cesarean)

- Pregnant women between the ages of 18-50

Exclusion Criteria:

- Patient who are not pregnant

- Patients unwilling or unable to provide consent

- Patients under the age of 18

- Patients who are incarcerated