Aeromedical repatriation of pregnant women

Even in the most sophisticated and spacious airambulance aircraft (e.g. Bombardier Challenger 604 or similar), acceptance of the risk of a delivery in-flight is not an option. An in-flight delivery is prohibitive due to an excessive risk for mother and fetus, poor monitoring capabilities of fetal wellbeing, non-existent possibilities to escalate to an assisted vaginal delivery and/ or a potential caesarian section. There are also very limited options for the management of post-partal and post-natal complications like maternal post-partum hemorrhage (i.e. the excessive bleeding following the birth of a baby). The main consideration for any woman with threating preterm labor abroad is therefore the decision to either be repatriated to the country of origin, or alternatively to the nearest country with advanced obstetric services (inutero transfer of the fetus) or to stay in the current location and transport mother and baby home after delivery (post-natal transfer of the newborn). A number of important variables influence the balanced risk-benefit analysis of such a decision:

• quality of local obstetric and neonatal services in relation to gestational age
• quality of local obstetric services in relation to known maternal and fetal risk factors and co-morbidities
• Distance and anticipated transport times
• Available options for diverting the flight in case of unforeseen progression of labor

In women with highly acute labor, in-utero transfer of the fetus is no longer an option since delivery en-route carries an unacceptable risk to mother and baby and must be avoided at all costs. Depending on the quality of locally available obstetric services in relation to gestational age and maternal/ fetal risk factors, support by sending an obstetric/neonatal team for a planned delivery with full equipment (incubator, surfactant, HFO, iNO, etc.) might be considered in exceptional circumstances.

Since the risk for intraventricular hemorrhage in extremely preterm babies is particularly high in the first 72 hours of life, minimal handling is recommended in this period and inter-facility transfers are discouraged, making a prolonged stay of the neonatal team a necessity in some very high-risk infants. Combined transports of mother and baby may be a possibility in large body air ambulance aircraft such as the Bombardier Challenger 604 and others.

In our own practice, careful assessment of the acuity of labor, taking into account all available data prior to the transfer such as the information on cervical length and dilatation, rupture of membranes, need for tocolysis (drugs used for the Inhibition of uterine contractions), active amnion infection syndrome, molecular markers etc., proved to be effective to prevent in-flight deliveries. Our current protocol stipulates tocolysis in standby during the transport of a pregnant woman with threating pre-term delivery. If the air ambulance team would observe any signs of progression into labor (such as re-occurrence of active contractions), the patient is started on tocolysis.

Depending on the efficacy of tocolysis and the location of the aircraft in relation to the planned destination, the flight may be diverted to the nearest facility with adequate obstetric and neonatal services. Planning of alternative airfields/destinations for different sectors of the flight prior to the transport allows quick and accurate decision making. Advanced communication equipment such as satellite telephones and messaging services enable the team to efficiently arrange ground ambulance pick-up and admission while still in the air.

An international aeromedical repatriation of a woman with threating preterm delivery might span a period of 24h or more from decision making until arrival in the admitting hospital, which means that criteria for local and regional transfers may not uniformly being applied to international transports. Nevertheless, our own data as well as the published literature support the hypothesis that long-distance aeromedical repatriation of women at risk for preterm labor and delivery can be performed with reasonable safety. We suggest the following criteria as indicators for possible international aeromedical repatriation related to the Interpretation of Clinical Findings in women with threating preterm labor in respect to the risk to progress into delivery:

• No signs suggestive of developing chorioamnionitis (an infection that can occur before labor, during labor or after delivery)
• No contractions in the 24h prior to transport
• Negative molecular markers (fFN, PAMG-1, phIGFBP-1), if locally available
• Preserved cervix of 3 cm or more or
• Cervical dilatation of less than 1 cm

Despite the obvious assessment of the progress of labor, decision criteria to stay or transport should always critically consider local capacities in relation to gestational age and co-morbidities of fetus and mother. Above all, an open and candid discussion of all available options with parents and all other relevant stakeholders are key in planning of such an air ambulance transfer.

You can read the full version of this article here.

Authors: Alex Veldman, Ryan Hodges, Michael Diefenbach, Cornelia Rohrbeck, Ruby Pannu, Sophie Schmitt-Kästner and Doris Fischer
This article is a shortened version of a scientific study, first published in Clinical Obstetrics, Gynecology and Reproductive Medicine 2020, Vol. 6, doi: 10.15761/COGRM.1000294