title: Does air travel affect pregnancy outcome?
abstract: METHODS
  To evaluate if air travel affects pregnancy outcome, all women with singleton, non anomalous fetuses, admitted for delivery at a gestational age >20.0 weeks over a 6-month period were asked if they traveled by airflight during pregnancy, including details of the destination and length of their flights and any complications during the travel. Pregnancy outcome was obtained by chart review. Statistical analysis included Student's t-test, Mann-Whitney U test, chi square, Fisher's exact test where appropriate, and linear and logistic regression analysis, with p<0.05 considered significant.
  
  
  RESULTS
  Two hundred twenty-two women were studied. Of these, 53% ( n=118) traveled at least once during pregnancy (median 2 flights, range 1-12). The first flight was taken at a mean +/- standard deviation gestational age of 13.3+/-7.6 weeks with average flight lasting 4+/-2 h. There were no differences in gestational age at delivery (39.1 vs. 38.4 weeks, p=0.07), neonatal birthweight (3,379 vs. 3,273 g, p=0.24), or rates of vaginal bleeding (2% vs. 5%, p=0.26), preterm delivery <37 weeks (9% vs. 14%, p=0.29), preeclampsia (5% vs. 6%, p=0.76), neonatal intensive care unit admission (13% vs. 16%, p=0.56), or cumulative adverse obstetric outcome ( p=0.61) between those who did and did not air travel during pregnancy. Power analysis demonstrated that a sample size of 2,803 women in each group would be necessary to show that air travel has a protective effect against adverse pregnancy outcome (alpha = 0.05, beta = 0.80). There were no thromboembolic events complicating any of the pregnancies.
  
  
  CONCLUSIONS
  Our findings suggest that air travel is not associated with increased risk of complications for pregnancies that reach 20 weeks' gestation.
authors.affiliation: Department of Obstetrics and Gynecology, Georgetown University Medical Center, 3800 Reservoir Road N.W., Washington, D.C. 20007, USA.
authors.forename: Mala
authors.initials: M
authors.lastname: Freeman
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ghidini
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Nana
authors.initials: N
authors.lastname: Tchabo
authors.forename: Patricia Z
authors.initials: PZ
authors.lastname: Bannon
authors.forename: John C
authors.initials: JC
authors.lastname: Pezzullo
mesh_terms: D000328:Adult; D000401:Aircraft; D016022:Case-Control Studies; D015331:Cohort Studies; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000209:etiology; D011256:Pregnancy Outcome; D012307:Risk Factors; D014195:Travel