In medical malpractice involving high-risk obstetrics, the underlying error is sometimes not a clinical decision but a procedural one: the failure to involve a specialist in time. KY v Bahler, 2023 ABKB 280, is an Alberta Court of King’s Bench decision in which a family physician’s failure to complete a referral letter set in motion a chain of events that ended with twin daughters born with severe and permanent neurological injuries. The trial judge found liability and worked through the causal chain step by step.
The case is from Alberta, not Ontario, but the principles it applies are common to Canadian medical malpractice law, and the analysis is directly relevant to Ontario obstetric and birth-injury claims.
The facts
The plaintiff (referred to in the decision as KY to protect the privacy of her children) was pregnant with monochorionic diamniotic twins. Such pregnancies have a single shared placenta and two separate amniotic sacs. They are well recognized in obstetric practice as high-risk, with notably elevated rates of complications including twin-to-twin transfusion syndrome (TTTS), a condition in which the shared placenta produces an imbalance in blood flow between the twins.
The defendant, Dr. Bahler, was a family physician whose practice was restricted to low-risk pregnancies. On August 11, 2009, he correctly identified the high-risk nature of KY’s pregnancy and started a referral letter to an obstetrician. The letter was never completed and never sent. KY herself contacted his office to follow up. It was still not completed.
Twenty-three days later, on September 3, 2009, KY presented in distress at Red Deer Regional Hospital. The twins were in a severe stage of TTTS. KY was transferred to Foothills Medical Centre in Calgary and then by air ambulance to Mount Sinai Hospital in Toronto for assessment for surgical intervention. By the time of those assessments, no intervention was feasible. The twins were delivered prematurely.
Both twins were diagnosed with periventricular leukomalacia, a hypoxic-ischemic brain injury affecting the white matter adjacent to the brain’s ventricles. Both now live with cerebral palsy. One twin uses a power wheelchair and has severe cerebral palsy affecting her right arm and both legs. The other has right spastic hemiplegia and wears a brace on her right leg. Both are cognitively impaired and have language and motor difficulties.
The family pursued the claim against Dr. Bahler. Damages were partially settled before trial, leaving liability for the trial judge to decide.
Standard of care
The trial judge held that Dr. Bahler had breached the standard of care of a family physician whose practice was restricted to low-risk pregnancies. Once he correctly identified the pregnancy as high-risk, the obligation was to ensure timely referral to an obstetrician for ongoing obstetrical management. Beginning a referral letter on August 11 and not completing or sending it, even after KY herself prompted the office, fell below the standard.
This is a narrow standard-of-care holding, but a useful one. A family physician who restricts a practice to low-risk obstetrics is competent to provide care within that boundary. When a pregnancy crosses out of that boundary into high-risk territory, the family physician’s obligation is to make the transition to specialist care happen, not to continue providing care that the family physician’s own practice limits exclude.
Causation
The trial judge worked through the causal chain in detail. The analysis is worth setting out because it is a model of how to bridge a procedural breach (the unsent referral) to a complex obstetric outcome (severe TTTS, premature delivery, cerebral palsy). In summary, the trial judge found that, had the referral been made on or about August 11, 2009:
- An obstetrician’s surveillance, supplemented by KY’s own concerns about her changing condition, would have detected the emerging TTTS at a stage early enough to permit intervention
- The TTTS in this case was acute rather than chronic, but it still required time, measured in days, to reach the severe stage at which KY actually presented. Earlier surveillance would have caught it before that point
- At the time of detection, the appropriate intervention would have been selective fetoscopic laser photocoagulation (SFLP), a surgical procedure available at Mount Sinai Hospital that addresses the placental vascular communications underlying TTTS
- KY would have been a candidate for SFLP. She would not have been in labour, the placental anatomy would not have precluded it, and the gestational age would have been within the procedure’s window
- SFLP itself would not have harmed the twins, and both would have survived the procedure
- SFLP would have corrected the circulatory imbalance and reduced the amniotic fluid pressure caused by TTTS. The twins would not thereafter have been harmed by TTTS
- KY’s pregnancy would have been prolonged
- The injuries the twins suffered as a consequence of premature birth would have been substantially reduced
The trial judge therefore concluded that, but for the failure to refer, the twins’ injuries would have been materially less severe than the injuries they actually suffered. Causation was established.
Expert evidence
The trial proceeded on a developed expert record. The plaintiffs called experts in maternal-fetal medicine (with TTTS subspecialty), family medicine and obstetrical care, paediatric neuroradiology, paediatrics and neonatology, and epidemiology. The defence called experts in the same areas. Each side covered the major analytical questions: standard of care for a family physician, causation through obstetric and surgical analysis, mechanism of brain injury, and statistical evaluation of outcomes.
The structure is typical of complex birth-injury litigation. A successful case at trial requires expert coverage of every link in the causal chain, with experts at the appropriate sub-specialty level. Where the chain is long, as it was here, the volume of expert evidence is substantial.
The doctrinal context
KY v Bahler sits in a long line of Canadian decisions on the obligation of physicians to refer when a clinical situation moves outside their competence or the limits of their practice. The general principle is uncontroversial: a physician who recognizes the need for a referral has an obligation to make that referral happen in a timely way. The case adds two useful applications of the principle.
First, in the context of a family practice that is restricted to low-risk obstetrics, the recognition of high-risk features triggers a clear obligation to transition the patient to specialist care. The family physician’s obligation does not end with starting a referral letter; it ends with the patient being received by the specialist, or at the very least with the specialist’s office having the referral and the patient knowing the next steps.
Second, in the context of a long causal chain (referral → specialist surveillance → detection of TTTS → SFLP → improved outcome), causation can be established by careful, step-by-step analysis with appropriate expert evidence at each step. The trial judge’s reasoning is a worked example of how to bridge a procedural breach to a complex clinical outcome where each step has alternatives but where, on the balance of probabilities, the chain holds together.
Why this case matters
For plaintiffs and their counsel. KY v Bahler is a strong precedent on the failure-to-refer fact pattern in obstetrics. It also illustrates the analytical approach to causation in cases where the breach is procedural rather than clinical. The judgment’s careful articulation of each link in the causal chain is a useful template for plaintiff submissions in similar cases, particularly birth-injury cases involving complications that could have been managed had a specialist been involved earlier. The case is from Alberta, but the principles are common Canadian law and the decision is citable in Ontario.
For defence counsel. The case is a reminder that a referral that is started but not completed is no defence. The substantive duty is to ensure the patient gets to the specialist; the bureaucratic act of starting a letter does not discharge it. Defence counsel reviewing files with referral issues should pay close attention to the documentary record of the referral process: when it was initiated, when it was followed up, when it was sent, when it was received, when the appointment was made. Gaps in that record are vulnerabilities.
For family physicians. KY v Bahler is a clear instruction that a family practice restricted to low-risk obstetrics requires robust office systems for transitioning patients to specialist care when high-risk features emerge. A referral letter that sits unsent on a desk, even briefly, is a failure of those systems. The case suggests that the referral process should be tracked as a standing item, with confirmation of receipt and confirmation of an appointment, not merely as a one-time letter.
For more on birth-injury claims in Ontario, see the Birth Injury practice page. For an Ontario birth-injury trial decision involving an obstetrician’s negligence in a similar twin-pregnancy setting, see Woods v Jackiewicz: An $11.5 Million Verdict for a Mismanaged Twin Pregnancy. For an overview of the legal process for medical malpractice claims in Ontario, see Suing for Medical Malpractice in Ontario: What You Need to Know.
Decision Date: May 8, 2023
Jurisdiction: Court of King’s Bench of Alberta
Citation: KY v Bahler, 2023 ABKB 280 (CanLII)
