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Multi-Year Research Grants
The Possible Association between Exposure to Air Pollution and Adverse
Pregnancy Outcomes
Objectives: To evaluate the possible association between exposure to air pollution
during pregnancy and adverse birth outcomes among children born following assisted
reproductive technology (ART) and spontaneously conceived (SC) pregnancies.
Methods: A historical cohort study comprising of 207,825 SC births and 8,905 ART births
in Israel during the period 1997-2004 was used. Air pollution data were obtained from
air monitoring stations and included SO
2
, PM
10
, NO
x
and O
3
. Geographic Information
System (GIS) and kriging procedures were used to assess exposures during pregnancy.
Logistic and Cox proportional hazards regression models were used to calculate the
adjusted risk for adverse pregnancy outcomes including congenital malformations (CM),
small for gestational age (SGA), low birth weight (LBW) and preterm birth (PTB). In
addition, Air-Quality-Indexes (AQIs) for adverse birth outcomes were calculated.
Results: Higher levels of SO
2
exposure were not associated with an increased risk of
any of the adverse outcomes. Increased levels of PM
10
exposure were associated with an
increased risk for CMand PTB, OR 1.06 (95%CI, 1.01-1.11) and OR 1.05 (95%CI, 1.02-1.08)
per 10µg/m
3
, respectively. Higher levels of NO
x
exposure were associated with increased
risk of CMand PTB, OR 1.03 (95%CI, 1.01-1.04) and OR 1.02 (95%CI, 1.01-1.04) per 10ppb
increase respectively. Higher levels of O
3
exposure were associated with an increased, risk
for SGA, OR 1.03 (95%CI, 0.99-1.08) and for LBW, OR 1.10 (95%CI, 1.02-1.18) per 10ppb
increase. In the ART group higher levels of SO
2
were associated with slightly higher risk
for CM and PTB and higher levels of O
3
exposure were associated with a slightly higher
risk for all adverse outcomes. The feasibility, under certain assumptions, of creating an
AQI for adverse birth outcomes has been demonstrated. Average air concentrations of
different pollutants in an Israeli town were analyzed, yielding possible adverse birth
outcomes as a function of 10µg/m
3
increases, PM
10
, and to a lesser extent, NO
x
.
Conclusion: Our initial results suggest that exposure to higher levels of air pollution
during pregnancy may be associated with various adverse pregnancy outcomes.
Although not significant, suggestion of higher impact of air pollution in the ART
pregnancies was observed particularly for O
3
exposure. Further studies are warranted,
including more accurate exposure data and a larger sample size for ART pregnancies to
confirm these associations.
Research publications
(1)
Farhi, A., Boyko, V., Almagor, Y., Benenson, I., Segre, E., Rudich, Y., Stern, E., & Lerner-Geva, L. (2014).
The possible association between exposure to air pollution and the risk for congenital malformations.
Environmental Research Journal, 135
, 173-180.
Liat Lerner-Geva
1,2
| Eli Stern
1
Yinon Rudich
3
| Adel Farhi
1
Itzhak Benenson
2
1. The Gertner Institute for
Epidemiology and Health Policy
Research
2. Tel Aviv University
3. Weizmann Institute of Science
2011-2014