Pulmonary embolism and stroke in relation to pregnancy: how can high-risk women be identified?
OBJECTIVE
Risks of circulatory diseases are increased substantially during late pregnancy and around the time of delivery. This study was undertaken to determine whether preeclampsia, multiple pregnancy, or cesarean delivery account for the majority of pregnancy-related risks of pulmonary embolism and stroke (caused by hemorrhage, infarction, and intracranial venous thrombosis).


METHODS
We analyzed a population-based cohort of 1,003,489 deliveries in Sweden. Relative risks of pulmonary embolism and stroke were modeled by use of Poisson regression.


RESULTS
Preeclampsia was associated with 3- to 12-fold increases in risks of pulmonary embolism and stroke during late pregnancy, at delivery, and in the puerperium, and similar increases in risks were also observed for multiple pregnancies and cesarean delivery. These strong associations could not explain the overall pregnancy-related risks of pulmonary embolism and stroke.


CONCLUSIONS
Preeclampsia, multiple birth, and cesarean delivery are important risk factors for pulmonary embolism and stroke, but they do not account for the majority of the excess risks associated with pregnancy.
Ros
Helena Salonen
HS
Department of Medical Epidemiology, Karolinska Institutet, Stockholm, Sweden. Helena.Ros@mep.ki.se
Lichtenstein
Paul
P
Bellocco
Rino
R
Petersson
Gunnar
G
Cnattingius
Sven
S
D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data; D011644:Puerperal Disorders / Q000453:epidemiology; D011655:Pulmonary Embolism / Q000453:epidemiology*; D012044:Regression Analysis; D018570:Risk Assessment / Q000379:methods; D020521:Stroke / Q000453:epidemiology*