Professor Greer concludes pregnant women should avoid flying from 37 weeks, rather than 36 weeks
There is no significant risk directly associated with air travel during pregnancy, even at advanced gestation, says report by the University of Liverpool.
Pro-Vice-Chancellor for Health and Life Sciences, Professor Ian Greer, explored the risks associated with flying during pregnancy for a report published by the Royal College of Obstetricians and Gynaecologists.
The report addresses the main cause for concern in pregnant women, which is the possibility of preterm labour or an obstetric emergency developing during flight.
Gestation period
These concerns form the basis of many airline carrier policies that prohibit pregnant women, who are over 36 weeks gestation, from flying.
Professor Greer concludes that it should be advised that pregnant women avoid air travel from 37 weeks gestation in an uncomplicated single pregnancy and if there are significant risk factors for preterm labour (such as multiple pregnancies) women should not fly from 32 weeks gestation.
While environmental and physiological changes that occur with alterations in cabin altitude are also raised as a common concern for pregnant women, the report suggests that this poses no direct risk on pregnancy complications. Although there is a reduction in the partial pressure of oxygen during flight, the paper outlines that this should not cause a problem in healthy pregnant women.
Other physiological changes highlighted that may cause more of an increased risk for discomfort and possible medical complications in the mother, are motion sickness, which may exacerbate morning sickness, and the duration of the flight with immobility, which increases the risk of deep vein thrombosis (DVT).
Being immobile and cramped for prolonged periods of time is a particular concern to pregnant women as the likelihood of developing DVT, although small, is increased by such conditions. It is generally accepted that prolonged air travel results in a 3-fold increase in incidence of thrombosis, with an additional 18% higher risk for each two hour increase in flight duration.
To minimise this risk further, Professor Greer offers suggestions to pregnant women flying on medium to long-haul flights (four hours or longer), including the use of graduated elastic compression stockings and for those with significant risk factors for DVT (such as previous thrombosis or morbid obesity), treatment with low-molecular-weight heparin (LMWH) should be considered for the day or travel and several days thereafter.
Body scanners
The paper rules out some common concerns around the use of body scanners, which use ionising radiation for security checks, suggesting they pose no additional hazard to pregnant women as the dose level used is not considered a substantial risk.
Professor Greer said: “For uncomplicated pregnancies there is no reason to give advice against commercial air travel. There is no issue with travel in early pregnancy, as the main consideration is risk of labour.
“However if the woman has a history of miscarriage or ectopic pregnancy it would be sensible to suggest ultrasound prior to travel to confirm the location and viability of the pregnancy.
“While the risk of developing DVT in flight varies depending on the individual’s risk factors, it is a concern of most pregnant women and there is reasonable evidence to support the use of graduated elastic compression stockings to reduce this risk further.”
For access to the full guidance: http://www.rcog.org.uk/womens-health/clinical-guidance/air-travel-and-pregnancy
