436 P.3d 803
Wash.2019Background
- Baby L.M. suffered severe, likely permanent brachial plexus injuries (ruptures/avulsions to all five nerve roots) during birth and sued the delivering midwife, Laura Hamilton, for negligence alleging excessive traction during shoulder dystocia.
- Hamilton defended that natural forces of labor (NFOL) can cause permanent brachial plexus injuries (BPIs) and presented medical literature (including the 2014 ACOG report) and expert testimony to that effect.
- L.M. moved to exclude NFOL evidence under Frye (novel/scientific acceptance) and to exclude/limit biomechanical expert Allan Tencer under ER 702 (unqualified/unhelpful). The trial court initially excluded NFOL evidence but, on reconsideration, admitted it and allowed Dr. Tencer to testify (with limits on specific causation).
- A jury found Hamilton not negligent. The Court of Appeals affirmed, and the Washington Supreme Court granted review.
- The Supreme Court reviewed the Frye question de novo and ER 702 admissibility for abuse of discretion, ultimately affirming the trial court: NFOL theory is not novel science for Frye purposes, and admitting Dr. Tencer did not constitute an abuse of discretion.
Issues
| Issue | Plaintiff's Argument (L.M.) | Defendant's Argument (Hamilton) | Held |
|---|---|---|---|
| Admissibility under Frye: whether NFOL theory is "generally accepted" science | NFOL is not generally accepted as a cause of severe permanent BPIs (avulsions/ruptures); literature is silent or disputed, so Frye exclusion required | NFOL as a cause of permanent BPIs is grounded in generally accepted medical literature (ACOG report and other peer-reviewed sources); deduction to specific injuries is permissible | Frye does not require general acceptance of each specific causation deduction; underlying theory (NFOL can cause permanent BPI) and its methodologies are generally accepted — NFOL evidence admissible |
| Admissibility under ER 702: whether Dr. Allan Tencer was qualified and his testimony would help the jury | Tencer lacks specialized expertise in childbirth biomechanics and relied on limited/insufficient data; his testimony is speculative and risks misleading the jury | Tencer is a biomechanical engineer experienced with forces on human tissue, reviewed the relevant literature (including ACOG) and can explain forces to aid the jury; specific causation was barred | Trial court did not abuse its discretion: Tencer was sufficiently qualified by knowledge/experience to explain biomechanical forces and his testimony was helpful; reliability/foundation issues were for cross-examination |
| Standard of review / scope of Frye inquiry | Trial court erred by failing to require general acceptance of the specific causal link (NFOL → avulsion/rupture) | Frye requires general acceptance only of the underlying theory/methodology, not every specific case-level causal deduction | Court reaffirmed de novo review for Frye and that Frye focuses on general acceptance of underlying science, not every discrete deduction |
Key Cases Cited
- Anderson v. Akzo Nobel Coatings, Inc., 172 Wn.2d 593 (recognizing Frye does not require general acceptance of each specific causation deduction)
- Lakey v. Puget Sound Energy, Inc., 176 Wn.2d 909 (ER 702 admissibility standard; exclusion for unreliable or unhelpful expert testimony)
- Johnston-Forbes v. Matsunaga, 181 Wn.2d 346 (expert testimony must have adequate foundation under ER 702)
- State v. Riker, 123 Wn.2d 351 (Frye requires general acceptance of underlying theory and techniques)
- State v. Gregory, 158 Wn.2d 759 (de novo review when Frye hearing not held below)
- State v. Baity, 140 Wn.2d 1 (sources to examine for Frye include record, literature, and other jurisdictions)