Akl Natalie, Coghlan Edwina A, Nathan Elizabeth A, Langford Stephen A, Newnham John P
School of Women's and Infants' Health, King Edward Memorial Hospital, University of Western Australia, Subiaco, WA 6008, Australia..
Aust N Z J Obstet Gynaecol. 2012 Aug;52(4):327-33. doi: 10.1111/j.1479-828X.2012.01426.x. Epub 2012 Apr 11.
For more than three decades, women at imminent risk of preterm birth (PTB) in Western Australia have been transferred by small aircraft over long distances to the single tertiary level perinatal centre in Perth, with no known case of birth during the flight. We aimed to review recent experience to understand how aircraft travel may delay PTB.
Retrospective observational study of 500 consecutive Royal Flying Doctor Service (RFDS) transfers of women at risk of preterm labour to the tertiary referral centre, from September 2007 to December 31, 2009.
In-flight delivery, complications associated with transfer and factors associated with delay in preterm delivery.
There were no in-flight deliveries or serious complications associated with the aeromedical transfer of these patients. In a multivariable Cox proportional hazards regression analysis, clinical factors in the presentation that were associated with a shorter time from landing to subsequent delivery included cervical dilatation ≥ 4 cm, ruptured membranes, gestational age > 32 weeks and nulliparity. The aircraft reaching an ambient altitude > 14,000 feet, or cabin altitude above zero (sea level), was associated with a delay in time from landing to delivery for women who were not in spontaneous preterm labour.
Our findings add to a 30-year experience that women at risk of preterm labour do not deliver during aeromedical transfer. Ambient and cabin altitude of the aircraft were associated with an extension in the time to delivery after arrival. The mechanisms underpinning this effect warrant further investigation.
三十多年来，西澳大利亚州面临早产迫在眉睫风险的妇女一直通过小型飞机被长途转运至珀斯唯一的三级围产期中心，且尚无飞行途中分娩的已知病例。我们旨在回顾近期经验，以了解飞机旅行如何可能延迟早产。
对2007年9月至2009年12月31日期间连续500例由皇家飞行医生服务组织（RFDS）转运至三级转诊中心的有早产风险的妇女进行回顾性观察研究。
飞行中分娩、与转运相关的并发症以及与早产延迟相关的因素。
这些患者的航空医疗转运过程中没有发生飞行中分娩或严重并发症。在多变量Cox比例风险回归分析中，就诊时与从着陆到随后分娩时间较短相关的临床因素包括宫颈扩张≥4厘米、胎膜破裂、孕周>32周和初产。对于未发生自发性早产的妇女，飞机达到环境高度>14,000英尺或客舱高度高于零（海平面）与从着陆到分娩的时间延迟相关。
我们的研究结果进一步丰富了长达30年的经验，即有早产风险的妇女在航空医疗转运期间不会分娩。飞机的环境高度和客舱高度与到达后分娩时间的延长相关。这种效应的潜在机制值得进一步研究。
