BACKGROUND
Pregnancy and air travel independently increase the risk of venous thrombosis. However,
there is a lack of data regarding the added risk, if at all, of thrombosis after air
travel during pregnancy.
OBJECTIVE
This study aimed to determine the potential added risk of venous thromboembolism among
pregnant women who traveled by air.
STUDY DESIGN
This was an observational retrospective study using data from 452,663 live births
between the years 2010 to 2019. The study group consisted of women who flew during
pregnancy. Data of pregnant women who flew during pregnancy were compared with that
of pregnant women who did not fly during pregnancy. The primary outcome was venous
thromboembolism during pregnancy and in the postpartum period. A case of venous thromboembolism
was deemed related to air travel only if it occurred up to 8 weeks after the return
flight (exposure time). Propensity score weighting Poisson regression was calculated
to assess the effect and to control selection biases. Risk per day was calculated.
RESULTS
Overall, 421,125 live births were included. Of those cases, 33,674 (8%) had traveled
by air during pregnancy (study group), and 387,451 (92%) did not (control group).
There were 6 cases of venous thromboembolism after a flight that occurred during the
exposure time of 8 weeks and 285 cases of venous thromboembolism in the control group
(0.05% vs 0.07%; P=.158). When the propensity weighting Poisson regression was calculated as risk per
day, there was a significantly increased risk between the study and control groups
(0.00031% vs 0.00022%; hazard ratio, 1.406; P=.005).
CONCLUSION
The overall risk of venous thromboembolism after air travel is low; however, our study
found that the risk of venous thromboembolism during pregnancy is increased by air
traveling.
Keywords
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Article info
Publication history
Published online: September 14, 2022
Accepted:
September 11,
2022
Received in revised form:
September 6,
2022
Received:
July 6,
2022
Footnotes
The authors report no conflict of interest.
Cite this article as: Ram S, Ram HS, Neuhof B, et al. Air travel during pregnancy and the risk of venous thrombosis. Am J Obstet Gynecol MFM 2022;XX:x.ex–x.ex.
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