Chronic air pollution exposure during pregnancy and maternal and fetal C-reactive protein levels: the Generation R Study.
BACKGROUND
Exposure to air pollution has been associated with higher C-reactive protein (CRP) levels, suggesting an inflammatory response. Not much is known about this association in pregnancy.


OBJECTIVE
We investigated the associations of air pollution exposure during pregnancy with maternal and fetal CRP levels in a population-based cohort study in the Netherlands.


METHODS
Particulate matter (PM) with an aerodynamic diameter ≤ 10 μm (PM10) and nitrogen dioxide (NO2) levels were estimated at the home address using dispersion modeling for different averaging periods preceding the blood sampling (1 week, 2 weeks, 4 weeks, and total pregnancy). High-sensitivity CRP levels were measured in maternal blood samples in early pregnancy (n = 5,067) and in fetal cord blood samples at birth (n = 4,450).


RESULTS
Compared with the lowest quartile, higher PM10 exposure levels for the prior 1 and 2 weeks were associated with elevated maternal CRP levels (> 8 mg/L) in the first trimester [fourth PM10 quartile for the prior week: odds ratio (OR), 1.32; 95% confidence interval (CI): 1.08, 1.61; third PM10 quartile for the prior 2 weeks: OR, 1.28; 95% CI: 1.06, 1.56]; however, no clear dose-response relationships were observed. PM10 and NO2 exposure levels for 1, 2, and 4 weeks preceding delivery were not consistently associated with fetal CRP levels at delivery. Higher long-term PM10 and NO2 exposure levels (total pregnancy) were associated with elevated fetal CRP levels (> 1 mg/L) at delivery (fourth quartile PM10: OR, 2.18; 95% CI: 1.08, 4.38; fourth quartile NO2: OR, 3.42; 95% CI: 1.36, 8.58; p-values for trend < 0.05).


CONCLUSIONS
Our results suggest that exposure to air pollution during pregnancy may lead to maternal and fetal inflammatory responses.
Generation R Study Group, Erasmus Medical Center, Rotterdam, the Netherlands. e.vandenhooven@erasmusmc.nl
Edith H
EH
van den Hooven
Yvonne
Y
de Kluizenaar
Frank H
FH
Pierik
Albert
A
Hofman
Sjoerd W
SW
van Ratingen
Peter Y J
PY
Zandveld
Jan
J
Lindemans
Henk
H
Russcher
Eric A P
EA
Steegers
Henk M E
HM
Miedema
Vincent W V
VW
Jaddoe
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009426:Netherlands; D010316:Particle Size; D011247:Pregnancy; D055815:Young Adult
D000393:Air Pollutants; D002097:C-Reactive Protein