Low-dose aspirin for prevention of morbidity and mortality from preeclampsia: a systematic evidence review for the U.S. Preventive Services Task Force.
BACKGROUND
Preeclampsia is a leading cause of maternal and perinatal morbidity and mortality.


OBJECTIVE
To systematically review benefits and harms of low-dose aspirin for preventing morbidity and mortality from preeclampsia.


METHODS
MEDLINE, Database of Abstracts of Reviews of Effects, PubMed, and Cochrane Central Register of Controlled Trials (January 2006 to June 2013); previous systematic reviews, clinical trial registries, and surveillance searches for large studies (June 2013 to February 2014).


METHODS
Randomized, controlled trials (RCTs) to assess benefits among women at high preeclampsia risk and RCTs or large cohort studies of harms among women at any risk level. English-language studies of fair or good quality were included.


METHODS
Dual quality assessment and abstraction of studies.


RESULTS
Two large, multisite RCTs and 13 smaller RCTs of high-risk women (8 good-quality) were included, in addition to 6 RCTs and 2 observational studies of average-risk women to assess harms (7 good-quality). Depending on baseline risk, aspirin use was associated with absolute risk reductions of 2% to 5% for preeclampsia (relative risk [RR], 0.76 [95% CI, 0.62 to 0.95]), 1% to 5% for intrauterine growth restriction (RR, 0.80 [CI, 0.65 to 0.99]), and 2% to 4% for preterm birth (RR, 0.86 [CI, 0.76 to 0.98]). No significant perinatal or maternal harms were identified, but rare harms could not be ruled out. Evidence on long-term outcomes was sparse, but 18-month follow-up from the largest trial found no developmental harms.


CONCLUSIONS
Benefits may have been overestimated due to small-study effects. Predictive intervals were not statistically significant. Future studies could shift findings toward the null.


CONCLUSIONS
Daily low-dose aspirin beginning as early as the second trimester prevented clinically important health outcomes. No harms were identified, but long-term evidence was limited.
Jillian T
JT
Henderson
Evelyn P
EP
Whitlock
Elizabeth
E
O'Connor
Caitlyn A
CA
Senger
Jamie H
JH
Thompson
Maya G
MG
Rowland
D026683:Advisory Committees; D001241:Aspirin / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D011225:Pre-Eclampsia / Q000188:drug therapy* / Q000401:mortality; D011247:Pregnancy; D047928:Premature Birth / Q000209:etiology / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic
D001241:Aspirin