Advances in fetal therapy

Precarious hope: Ethical considerations for offering experimental fetal therapies outside of research after initial studies in humans

OBJECTIVE

Risks and benefits of experimental fetal therapies can remain uncertain after initial clinical studies, especially long-term effects. Nevertheless, pregnant individuals may request them, hoping to benefit their future child. Guidance about offering experimental fetal therapies outside research (as "innovative therapy") is limited, despite their ethical complexity. We propose points for clinicians and reviewers to consider when deciding whether and how to offer experimental fetal therapies as innovative therapies after initial clinical studies.

METHOD

We used conceptual analysis and a current case to develop points for consideration, grounded in broader debates on innovative therapy and the unique challenges associated with experimental fetal therapies.

RESULTS

Clinicians should evaluate whether offering experimental fetal therapies as innovative therapy is appropriate for a pregnant individual and their fetus. The anticipated risk-benefit ratio for the fetus should be favorable. For the pregnant individual, risks may outweigh benefits, within reasonable limits. Medical resources should be sufficient to ensure appropriate care. Clinicians should support pregnant individuals in making informed choices. Clinicians offering innovative therapies with more than minimal risk should collect and report data on outcomes. Independent review should take place.

CONCLUSION

Considering these points may advance the interests of fetuses, future children, and their families.

A new ethical framework to determine acceptable risks in fetal therapy trials

OBJECTIVE

Fetal therapy trials pose complex ethical challenges because risks and benefits to both fetuses and pregnant persons must be considered. Existing regulatory guidance is limited and many proposed ethical frameworks have unnecessarily restrictive criteria that would block the development and implementation of important new fetal therapies. We aimed to develop a new ethical framework for assessing the risks and benefits of fetal therapy trials.

METHODS

We reviewed existing regulatory and ethical guidance on fetal therapy trials. We used conceptual analysis to design a new ethical framework, which is grounded in general ethical principles for clinical research.

RESULTS

We propose a new framework for assessing the risks and benefits of fetal therapy trials. We suggest that the potential benefits of a fetal therapy trial - for the fetus, the pregnant person, and society - should outweigh the risks for the fetus and the pregnant person. Furthermore, the risk-benefit profile for just the fetus and the risk-benefit profile for just the pregnant person should be appropriate.

CONCLUSIONS

We hope that this new framework will permit important studies while protecting pregnant persons and fetuses from disproportionate harms.

A New Ethical Framework for Assessing the Unique Challenges of Fetal Therapy Trials

New fetal therapies offer important prospects for improving health. However, having to consider both the fetus and the pregnant woman makes the risk-benefit analysis of fetal therapy trials challenging. Regulatory guidance is limited, and proposed ethical frameworks are overly restrictive or permissive. We propose a new ethical framework for fetal therapy research. First, we argue that considering only biomedical benefits fails to capture all relevant interests. Thus, we endorse expanding the considered benefits to include evidence-based psychosocial effects of fetal therapies. Second, we reject the commonly proposed categorical risk and/or benefit thresholds for assessing fetal therapy research (e.g., only for life-threatening conditions). Instead, we propose that the individual risks for the pregnant woman and the fetus should be justified by the benefits for them and the study's social value. Studies that meet this overall proportionality criterion but have mildly unfavorable risk-benefit ratios for pregnant women and/or fetuses may be acceptable.

Homing of allogeneic nestin-positive hair follicle-associated pluripotent stem cells after maternal transplantation in experimental model of cortical dysplasia

An embryo has the capability to accept allo- or xeno-geneic cells, which probably makes it an ideal candidate for stem cell transplantation of various cerebral cortex abnormalities, such as cortical dysplasia. The aim of this study was to determine hair follicle-associated pluripotent (HAP) stem cells homing into various organs of mother and fetus. Cells were obtained, analyzed for immunophenotypic features, and then labelled with CM-Dil; nestin+HAP stem cells or media phosphate-buffered saline (PBS) were intravenously delivered on day 16 of gestation in BALB/c mice, which intraperitoneally received methylazoxymethanol (MAM) one day in advance, and homing was assessed at 24 h after cell injection. Flow cytometry and immunocytochemistry manifested positive expression of nestin in HAP stem cells. For both mother and fetus, brain, lungs, liver, and spleen were the host organs for cell implants. For the brain, the figure was considerably higher in fetus, 4.05 ± 0.5% (p ≤ 0.05 vs. mother). MAM-injected mice had a downward trend for SDF-1α and CXCR4 (p ≤ 0.05 vs. control), but HAP stem cells group showed an upward trend for CXCR4 (p ≤ 0.05 vs. MAM). We conclude the HAP stem cells show homing potential in experimental cortical dysplasia, which may permit these cells to be a target in future work on prenatal therapy of neural disorders.

Towards scene adaptive image correspondence for placental vasculature mosaic in computer assisted fetoscopic procedures

BACKGROUND

Visualization of the vast placental vasculature is crucial in fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome treatment. However, vasculature mosaic is challenging due to the fluctuating imaging conditions during fetoscopic surgery.

METHOD

A scene adaptive feature-based approach for image correspondence in free-hand endoscopic placental video is proposed. It contributes towards existing techniques by introducing a failure detection method based on statistical attributes of the feature distribution, and an updating mechanism that self-tunes parameters to recover from registration failures.

RESULTS

Validations on endoscopic image sequences of a phantom and a monkey placenta are carried out to demonstrate mismatch recovery. In two 100-frame sequences, automatic self-tuned results improved by 8% compared with manual experience-based tuning and a slight 2.5% deterioration against exhaustive tuning (gold standard).

CONCLUSION

This scene-adaptive image correspondence approach, which is not restricted to a set of generalized parameters, is suitable for applications associated with dynamically changing imaging conditions. Copyright © 2015 John Wiley & Sons, Ltd.