Blood transfusion and cesarean delivery.
OBJECTIVE
To evaluate risks for intraoperative or postoperative packed red blood cell transfusion in women who underwent cesarean delivery.


METHODS
This was a 19-university prospective observational study. All primary cesarean deliveries from January 1, 1999, to December 31, 2000, and all repeat cesareans from January 1, 1999, to December 31, 2002, were included. Trained, certified research nurses performed systematic data abstraction. Primary and repeat cesarean deliveries were analyzed separately. Univariable analyses were used to inform multivariable analyses.


RESULTS
A total of 23,486 women underwent primary cesarean delivery, of whom 762 (3.2%) were transfused (median 2 units, 25th% to 75th% 2-3 units). A total of 33,683 women underwent repeat [corrected] cesarean delivery, and 735 (2.2%) were transfused (median 2 units, 25th% to 75th% 2-4 units). Among primary cesareans, general anesthesia (odds ratio [OR] 4.2, 95% confidence interval [CI] 3.5-5.0), placenta previa (OR 4.8, CI 3.5-6.5) and severe (hematocrit less than 25%) preoperative anemia (OR 17.0, CI 12.4-23.3) increased the odds of transfusion. Among repeat cesareans, the risk was increased by general anesthesia (OR 7.2, CI 5.9-8.7), a history of five or more prior cesareans (OR 7.6, CI 4.0-14.3), placenta previa (OR 15.9, CI 12.0-21.0), and severe preoperative anemia (OR 19.9, CI 14.5-27.2).


CONCLUSIONS
Overall, the risk of transfusion in association with cesarean is low. However, both severe preoperative maternal anemia and placenta previa are associated with markedly increased risks. The former argues for optimizing maternal antenatal iron status to avoid severe anemia and the latter for careful perioperative planning when previa complicates cesarean.


METHODS
II-2.
Rouse
Dwight J
DJ
Department of Obstetrics, the University of Alabama at Birmingham, Birmingham, Alabama 35249-7333, USA. drouse@uab.edu
MacPherson
Cora
C
Landon
Mark
M
Varner
Michael W
MW
Leveno
Kenneth J
KJ
Moawad
Atef H
AH
Spong
Catherine Y
CY
Caritis
Steve N
SN
Meis
Paul J
PJ
Wapner
Ronald J
RJ
Sorokin
Yoram
Y
Miodovnik
Menachem
M
Carpenter
Marshall
M
Peaceman
Alan M
AM
O'Sullivan
Mary Jo
MJ
Sibai
Baha M
BM
Langer
Oded
O
Thorp
John M
JM
Ramin
Susan M
SM
Mercer
Brian M
BM
D000740:Anemia / Q000150:complications* / Q000628:therapy; D016063:Blood Loss, Surgical; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D002585:Cesarean Section / Q000009:adverse effects*; D017604:Cesarean Section, Repeat / Q000009:adverse effects; D005260:Female; D006801:Humans; D016015:Logistic Models; D015999:Multivariate Analysis; D010923:Placenta Previa / Q000503:physiopathology*; D006473:Postpartum Hemorrhage / Q000628:therapy*; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic; D011446:Prospective Studies; D018570:Risk Assessment