The risk of adverse pregnancy outcomes is increased in preeclamptic women who smoke compared with nonpreeclamptic women who do not smoke.
OBJECTIVE
Maternal smoking and preeclampsia independently increase the risk of adverse pregnancy outcomes; however, smoking decreases the risk of preeclampsia. We sought to estimate the risk of adverse pregnancy outcomes among preeclamptic women who smoke and hypothesized that this risk would be increased, compared with nonpreeclamptic women who smoke or preeclamptic women who do not smoke.


METHODS
With the use of the Niday Perinatal Database and multiple logistic regressions, we estimated the risk of adverse pregnancy outcomes in nonpreeclamptic women who smoke, preeclamptic women who do not smoke, and preeclamptic women who smoke in relation to nonpreeclamptic women who do not smoke.


RESULTS
The incidence of adverse pregnancy outcomes was more than twice as high among preeclamptic women who smoke as among nonpreeclamptic women who do not smoke. The following data were observed: small-for-gestational-age infant (odds ratio [OR], 3.40; 95% CI, 2.27-4.89), preterm birth (OR, 5.77; 95% CI, 4.50-7.35), very preterm birth (OR, 5.44; 95% CI, 3.51-8.11), abruption (OR, 6.16; 95% CI, 3.05-11.01), Apgar <4 at 5 minutes (OR, 3.11; 95% CI, 1.48-5.72), and stillbirth (OR, 3.39; 95% CI, 1.33-6.99).


CONCLUSIONS
Smoking decreases the risk of preeclampsia, but smokers with preeclampsia have an increased risk for adverse pregnancy outcomes.
Miller
Elizabeth C
EC
OMNI Research Group, Clinical Epidemiology Unit, Ottawa Health Research Institute, The Ottawa Hospital, Ottawa, ON, Canada. 4ecm@queensu.ca
Cao
Huiling
H
Wen
Shi Wu
SW
Yang
Qiuying
Q
Lafleche
Julie
J
Walker
Mark
M
D000037:Abruptio Placentae / Q000453:epidemiology; D000328:Adult; D001034:Apgar Score; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D009864:Ontario / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology; D012306:Risk; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D050497:Stillbirth / Q000453:epidemiology