Risk of fetal death with preeclampsia.
OBJECTIVE
To estimate gestational age-specific risks of fetal death in pregnancies complicated by preeclampsia.


METHODS
Population-based cohort study comprising all singleton births (N=554,333) without preexisting chronic hypertension recorded in the Norwegian Medical Birth Registry from 1999 to 2008. Additional data come from a subset of preeclamptic pregnancies enrolled in the Norwegian Mother and Child Cohort Study with available medical records (n=3,037). The risk of fetal death, expressed per 1,000 fetuses exposed to preeclampsia, was calculated using a life table approach.


RESULTS
Preeclampsia was recorded in 3.8% (n=21,020) of all pregnancies. Risk of stillbirth was 3.6 per 1,000 overall and 5.2 per 1,000 among pregnancies with preeclampsia (relative risk 1.45, 95% confidence interval [CI] 1.20-1.76). However, relative risk of stillbirth was markedly elevated with preeclampsia in early pregnancy. At 26 weeks of gestation, there were 11.6 stillbirths per 1,000 pregnancies with preeclampsia compared with 0.1 stillbirths per 1,000 pregnancies without (relative risk 86, 95% CI 46-142). Fetal risk with preeclampsia declined as pregnancy advanced, but at 34 weeks of gestation remained more than sevenfold higher than pregnancies without preeclampsia.


CONCLUSIONS
For clinical purposes, the fetal risk of death associated with preeclampsia begins when preeclampsia becomes clinically apparent. Using a method that takes into account the clinical diagnosis of preeclampsia and the population of fetuses at risk, we find a remarkably high relative risk of fetal death among pregnancies diagnosed with preeclampsia in the preterm period.


METHODS
II.
Epidemiology and Biostatistics Branches, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, and the Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina; Xinhua Hospital and MOE-Shanghai Key Laboratory of Children's Environmental Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China; and the Medical Birth Registry of Norway, Norwegian Institute of Public Health, and the Department of Global Public Health and Primary Care, University of Bergen, Bergen, and the Norwegian Institute of Public Health, Oslo, Norway.
Quaker E
QE
Harmon
Lisu
L
Huang
David M
DM
Umbach
Kari
K
Klungsøyr
Stephanie M
SM
Engel
Per
P
Magnus
Rolv
R
Skjærven
Jun
J
Zhang
Allen J
AJ
Wilcox
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D006801:Humans; D009664:Norway / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D012042:Registries / Q000706:statistics & numerical data*; D018570:Risk Assessment; D055815:Young Adult