HG (Abduction): When Maternal Medical Unfitness to Fly Makes Compliance Impossible—Stay and Deferred Reconsideration of Set-Aside

1. Introduction

The appeal arose from Hague Convention proceedings concerning a young child (“HG”), born in the United States and later retained in England and Wales by the mother. The father sought the child’s summary return to Texas under the 1980 Hague Child Abduction Convention (“the 1980 Convention”).

A return order had been made in earlier proceedings: Re HG (A Child) (Abduction: Consent, Acquiescence, Art 13b) [2026] EWHC 1385 (Fam). No appeal was pursued against that return order. Instead, shortly before the return date, the mother applied (in person) to set aside or vary the order, relying on alleged deterioration in her perinatal mental and physical health and medical advice that she was unfit to undertake air travel in late pregnancy.

The High Court refused both to set aside and to stay the return order. The mother appealed that refusal. The Court of Appeal’s decision is notable for how it addresses the situation where compliance (as contemplated by the original order and its undertakings) becomes practically impossible for a temporary medical reason, and the only “immediate” implementation alternative would materially change the protective assumptions underpinning the original order (e.g., return with the father, separation from the mother).

2. Summary of the Judgment

• The Court of Appeal held that the existing return order (requiring the mother to take HG to the United States) could not realistically be implemented before the birth, given medical evidence that she was unfit to fly.
• The Court allowed the appeal against the refusal to stay the return order; a stay should have been granted on 19 June 2026 and was extended pending further determination.
• The Court also allowed the appeal in relation to set-aside in the sense that it directed a reconsideration of the set-aside application (stage (c) of the Re B framework) at a further hearing at least six weeks after the birth, before a different judge (preferably a full judge of the Family Division).
• The Court admitted fresh evidence (medical documents) on the appeal, concluding that the interests of justice required it (without undertaking a detailed Ladd v Marshall analysis).

3. Analysis

3.1 Precedents Cited and Their Role

(a) Re W (Abduction: Setting Aside Return Order) [2018] EWCA Civ 1904 [2019] 1 FLR 400

This case supplies the core jurisdictional proposition: the High Court has an inherent power to set aside a Hague return order where a fundamental change of circumstances undermines the basis on which the original order was made. In HG, that principle framed the mother’s application as something exceptional—distinct from an appeal, and subject to a high threshold.

The Court of Appeal accepted (as common ground) that the Re W standard governed the set-aside route and that the bar remained high.

(b) Family Procedure Rules 2010, rule 12.52A

Following Re W, rule 12.52A establishes procedure for set-aside applications in Hague cases and provides that if the court sets aside a return order, it must give directions for a rehearing or otherwise dispose of the application. In HG, the procedural architecture mattered because the Court of Appeal fashioned a remedy that did not finally decide the set-aside question but required a structured reconsideration at a later point when the factual matrix would inevitably be different.

(c) Re B (A child) (Abduction: Article 13(b)) [2020] EWCA Civ 1057 [2021] 1 FLR 721

Re B provided the key analytical framework (set out by Moylan LJ) for set-aside applications in Hague matters:

1. Whether to permit any reconsideration;
2. If so, the extent of further evidence;
3. Whether to set aside the existing order;
4. If set aside, redetermine the substantive application.

The parties agreed that, on 19 June 2026, the court was at stage (c). The Court of Appeal’s remedy is best understood as holding that stage (c) had to be revisited at a later date because the immediate “compliance scenario” assumed by the original return order (mother travelling with the child, safeguarded by undertakings) had become non-viable.

The Court also echoed the caution in Re B (paragraph 91) that courts must be astute to prevent attempts to re-argue or frustrate final Hague determinations. Importantly, the Court’s intervention was anchored not in permitting re-litigation, but in confronting an implementation impasse with welfare-protective consequences (including the risk profile of an alternative mode of return).

(d) ST v QR [2022] EWHC 2133 (Fam)

The judge at first instance relied on this authority (a decision of Dexter Dias KC sitting as a deputy High Court judge) alongside Re B when articulating the “high bar” and the need for a foundational failure or fundamental undermining change. The Court of Appeal did not dispute the general approach, but held that, on the facts now apparent (and, in its view, already apparent on 19 June), a stay was unavoidable and the set-aside application required later reconsideration.

(e) Ladd v Marshall [1954] 1 WLR 1489

The mother sought to rely on fresh medical material on appeal. The Court admitted it, noting its relevance to current medical condition and deciding that the interests of justice required consideration, without detailed application of the classic Ladd v Marshall tripartite test. The case illustrates that, in time-sensitive Hague contexts, appellate courts may take a pragmatic approach to fresh evidence where it goes to present feasibility and risk.

(f) Volpi v Volpi [2022] EWCA Civ 464

The father invoked Volpi for the proposition that appellate courts should give substantial weight to a trial judge’s evaluative conclusions and avoid interfering absent error. The Court of Appeal accepted the general restraint principle, but found the practical impossibility of compliance (and the consequences of the only alternative implementation) required intervention—especially regarding the stay.

(g) Senior Courts Act 1981, s.49(3) and Metropolitan Bank v Pooley (1884- 1885) LR 10 App Cas 210

These were cited to confirm the appellate and High Court power to stay proceedings/orders. The stay power was central: the Court of Appeal treated a stay not as an indulgence but as the only realistic mechanism to prevent either unlawful or unsafe “implementation by substitution” (i.e., return with the father) pending birth.

3.2 Legal Reasoning

(a) The decisive practical finding: the order could not be implemented as drafted

Although the litigation was framed as a challenge to the refusal to set aside/stay, the Court of Appeal identified a determinative reality: the return order required the mother to travel with the child, but medical advice (from treating clinicians, and later supported by additional records) rendered that presently impossible. That conclusion was ultimately conceded in substance on behalf of the father: even if an airline’s formal requirements differed, no airline would accept a passenger who had been diagnosed by two medical practitioners as unfit to fly.

(b) Why “return with the father now” was not an acceptable workaround

Once the Court accepted that the mother could not fly, it identified only two theoretical options:

• Return the child immediately with the father; or
• Stay the return until after the birth.

The Court held the first option “not realistic”, emphasising factual features going directly to Article 13(b)-type risk: the child had not seen the father for months, had never been separated from the mother, and was reportedly still breastfeeding; separation from the mother shortly before the birth of a sibling would be a fundamental change from the original order’s assumptions. The Court stated it was “at least arguable” that such a separation/return arrangement could create a grave risk of psychological harm or intolerability.

This is an important move: the Court treated “implementation by substitution” as potentially generating its own Article 13(b) risk profile, distinct from the risk analysis undertaken at the original return hearing (which proceeded on the common assumption that the mother would travel and remain the child’s primary carer in the United States, underpinned by undertakings).

(c) The stay: not a merits reversal, but a necessary holding position

The Court’s criticism of the refusal to stay was measured but clear: even if the judge was sceptical about the origins of the medical letters, they were opinions of treating clinicians that the mother was not fit to fly and “required further exploration”. Given the order’s compliance mechanism depended on the mother’s travel, a stay was the proportionate and necessary response.

(d) The set-aside: why the Court ordered reconsideration rather than deciding it finally

The Court identified an unusual but practically common dynamic in Hague cases: the change making compliance impossible (late pregnancy deterioration and advice not to fly) was likely temporary and might resolve after birth—meaning the “changed circumstances” might later change again. The Court therefore avoided an over-hasty conclusion that the return order must be set aside permanently.

Instead, it directed that stage (c) of the Re B process be reheard not less than six weeks after birth, when the court could assess:

• whether there remained a sufficiently fundamental change to undermine the original order;
• the mother’s postnatal mental and physical health;
• the reality of caring for two children and any effect on Article 13(b) risk;
• immigration/logistical consequences for the mother and the newborn.

The Court also confined the scope: the only aspect of the return order challenged on set-aside was the rejection of the Article 13(b) defence.

3.3 Impact

(a) A practical precedent on “non-implementable” Hague returns

The decision signals that where a return order is drafted on a particular implementation premise (here, mother-and-child travel supported by undertakings), and subsequent events make that premise temporarily impossible, courts should not force compliance through a materially different route without scrutinising whether that substitution itself generates Article 13(b)-type risks.

(b) Stays as a protective necessity, not a Hague “delay tactic” reward

While reaffirming the “high threshold” ethos of Re W and Re B, the Court demonstrates that a stay may be compelled by reality. This is not inconsistent with Hague expedition: it is a recognition that expedition cannot require unsafe travel or a welfare-dangerous separation merely to preserve timetable.

(c) Managing temporality: defer rather than decide irreversibly

The Court’s solution—extend the stay and remit stage (c) for later reconsideration—may become a template where changes are significant now but inherently time-limited (late pregnancy; acute medical episodes; short-term incapacity). It offers a structured approach that preserves the integrity of the original Hague determination while ensuring the “current” risk landscape is adjudicated at the relevant time.

(d) Evidence and case management

The decision underscores that treating clinicians’ evidence about fitness to travel can be case-dispositive on stay/implementation, even if the court retains caution about history and presentation. It also encourages proactive directions for updated evidence and a properly listed hearing (here, before a different judge and likely a full Family Division judge).

4. Complex Concepts Simplified

• 1980 Hague return order: a swift order requiring a child’s return to the country of habitual residence so that welfare decisions are made there, not in the “requested” state.
• Article 13(b) “grave risk” defence: an exception allowing refusal of return if return would expose the child to grave physical/psychological harm or otherwise place the child in an intolerable situation. It is deliberately narrow and strictly applied.
• Set-aside vs appeal: an appeal challenges whether the original decision was wrong at the time it was made; a set-aside application accepts finality but says later events have so undermined the basis of the order that it cannot stand.
• Fundamental change of circumstances: not any new difficulty, but a change that undermines the essential foundation of the original order (a high bar).
• Undertakings in Hague cases: promises (often about money, accommodation, non-prosecution, etc.) intended to reduce risk on return. They often assume a particular caregiving arrangement; if that arrangement collapses, the undertakings may no longer address the true risk.
• Stay: a temporary pause of the effect of an order. Here, it was used to prevent unsafe/impossible compliance and to avoid an alternative implementation that could itself create grave risk.

5. Conclusion

HG (Abduction: Application To Set Aside Return Order) [2026] EWCA Civ 971 reinforces the stringent threshold for setting aside Hague return orders (Re W; Re B) while making a clear, practical contribution: when a return order becomes temporarily non-implementable on its intended basis (here, because medical evidence renders a parent unfit to fly), the court should not treat immediate enforcement by an alternative route (such as separating the child and returning with the left-behind parent) as a mere logistical adjustment. Such a shift may amount to a fundamental change from the original protective assumptions and may itself raise Article 13(b) risk.

The Court of Appeal therefore treated a stay as unavoidable and ordered a structured, post-birth reconsideration of whether the changed circumstances ultimately justify setting aside the return order—preserving Hague principles of prompt return while preventing implementation that is either impossible or potentially harmful.