Periodic Reporting for period 4 - MARTE (Medically Assisted Reproduction: The Effects on Children, Adults and Families)
Reporting period: 2023-08-01 to 2025-04-30
The MARTE project investigates the consequences of medically assisted reproduction (MAR) for the well-being of adults, children, and families. While MAR use is increasing globally, existing evidence about its effects remains limited, often based on small, non-representative samples and lacking an understanding of whether these associations are causal. Key questions—such as whether MAR affects child development, adult mental health, or family stability—have not been comprehensively or causally addressed.
Understanding the implications of MAR is a public health and societal priority. Over 10 million births globally have involved MAR, with a growing number of adults undergoing treatment—some successfully, others not. Yet, the long-term consequences for health, education, family functioning, and mental well-being are poorly understood. This evidence is crucial for informing clinical guidelines, public health resource allocation, fertility policy, and counselling for couples considering or undergoing MAR.
MARTE set out to:
• Project A: Assess the impact of MAR on adults’ physical and mental health, life-course trajectories, and relationship stability, distinguishing between those who conceived through MAR and those who did not.
• Project B: Investigate how children conceived through MAR fare across multiple domains (e.g. physical health, mental health, education) compared to their spontaneously conceived peers—including their own siblings.
• Project C: Examine parent–child relationships in MAR families during adolescence, using data from both parents and children.
The project innovated by using large-scale population register data from Finland, Sweden, Norway, Utah and the UK, and applied quasi-experimental designs (e.g. sibling comparisons) to test causality. It also addressed gaps in knowledge about the longer-term consequences of MAR, variation by treatment type, the role of selection and cross-country comparability.
Conclusion of the action
The project generated compelling and policy-relevant findings:
• Adults who underwent MAR but did not conceive showed higher rates of long-term psychotropic use and union dissolution.
• Children conceived through MAR had worse birth outcomes but similar or better longer-term cognitive and educational outcomes, largely due to their parents’ socio-economic advantage.
• MAR-conceived adolescents had higher rates of mental health issues compared to their naturally conceived siblings, suggesting some potential vulnerabilities.
• No evidence was found that MAR conception negatively affects the quality of parent–child relationships during adolescence.
Understanding the implications of MAR is a public health and societal priority. Over 10 million births globally have involved MAR, with a growing number of adults undergoing treatment—some successfully, others not. Yet, the long-term consequences for health, education, family functioning, and mental well-being are poorly understood. This evidence is crucial for informing clinical guidelines, public health resource allocation, fertility policy, and counselling for couples considering or undergoing MAR.
MARTE set out to:
• Project A: Assess the impact of MAR on adults’ physical and mental health, life-course trajectories, and relationship stability, distinguishing between those who conceived through MAR and those who did not.
• Project B: Investigate how children conceived through MAR fare across multiple domains (e.g. physical health, mental health, education) compared to their spontaneously conceived peers—including their own siblings.
• Project C: Examine parent–child relationships in MAR families during adolescence, using data from both parents and children.
The project innovated by using large-scale population register data from Finland, Sweden, Norway, Utah and the UK, and applied quasi-experimental designs (e.g. sibling comparisons) to test causality. It also addressed gaps in knowledge about the longer-term consequences of MAR, variation by treatment type, the role of selection and cross-country comparability.
Conclusion of the action
The project generated compelling and policy-relevant findings:
• Adults who underwent MAR but did not conceive showed higher rates of long-term psychotropic use and union dissolution.
• Children conceived through MAR had worse birth outcomes but similar or better longer-term cognitive and educational outcomes, largely due to their parents’ socio-economic advantage.
• MAR-conceived adolescents had higher rates of mental health issues compared to their naturally conceived siblings, suggesting some potential vulnerabilities.
• No evidence was found that MAR conception negatively affects the quality of parent–child relationships during adolescence.
Over the course of the project, we implemented the full MARTE research agenda, resulting in over 20 publications and numerous conference presentations. The work was structured into three main strands aligned with the project’s objectives.
Project A: Adults undergoing MAR
We used population-wide register data from Finland, Norway, and Utah, alongside UK survey data, to examine mental and physical health outcomes of adults undergoing MAR, differentiating by treatment success.
Key findings:
- Individuals undergoing MAR without conceiving experience persistently worse mental health outcomes and higher risk of separation than those conceiving naturally or via MAR.
- Using individual fixed-effects and event-history models, we showed these effects are unlikely due to pre-existing differences.
- Adults conceiving via MAR face higher maternal morbidity risks, likely attributable to underlying infertility rather than the treatment itself.
Impact:
These results highlight the need for psychological support in fertility care, particularly after unsuccessful treatments.
Project B: Children conceived through MAR
We assessed outcomes across birth, health, cognitive development, education, and mental health using data from Finland, Sweden, Norway, Utah and the UK, including within-family comparisons.
Key findings:
- MAR children have higher risks of poorer birth outcomes, though this is unlikely to be due to the treatments per se and linked to underlying subfertility.
- Despite early health disadvantages, MAR children show comparable or better cognitive and educational performance.
- These advantages stem from socioeconomic selection: MAR families are typically more advantaged.
- However, MAR adolescents have slightly elevated mental health risks —even compared to their naturally conceived siblings.
Impact:
These findings challenge assumptions about MAR risks and underscore the complexity of outcomes.
Project C: Parent–child relationships
We used the UK Millennium Cohort Study to evaluate adolescent-parent relationships via self-reports from both groups.
Key findings:
- No significant differences in parent–child closeness between MAR and non-MAR families.
- Contrary to earlier concerns, no evidence of overprotectiveness or heightened conflict in MAR families during adolescence.
Impact:
The results provide reassurance regarding the psychosocial dynamics of MAR families and have informed family psychology and social policy debates.
Dissemination and outreach:
Findings were published in top journals (JAMA, Demography, IJE, PDR) and presented at leading conferences (Population Association of America, ESHRE, EPC). We also hosted a final dissemination workshop. Throughout the project we engaged with the media to broaden public understanding.
Project A: Adults undergoing MAR
We used population-wide register data from Finland, Norway, and Utah, alongside UK survey data, to examine mental and physical health outcomes of adults undergoing MAR, differentiating by treatment success.
Key findings:
- Individuals undergoing MAR without conceiving experience persistently worse mental health outcomes and higher risk of separation than those conceiving naturally or via MAR.
- Using individual fixed-effects and event-history models, we showed these effects are unlikely due to pre-existing differences.
- Adults conceiving via MAR face higher maternal morbidity risks, likely attributable to underlying infertility rather than the treatment itself.
Impact:
These results highlight the need for psychological support in fertility care, particularly after unsuccessful treatments.
Project B: Children conceived through MAR
We assessed outcomes across birth, health, cognitive development, education, and mental health using data from Finland, Sweden, Norway, Utah and the UK, including within-family comparisons.
Key findings:
- MAR children have higher risks of poorer birth outcomes, though this is unlikely to be due to the treatments per se and linked to underlying subfertility.
- Despite early health disadvantages, MAR children show comparable or better cognitive and educational performance.
- These advantages stem from socioeconomic selection: MAR families are typically more advantaged.
- However, MAR adolescents have slightly elevated mental health risks —even compared to their naturally conceived siblings.
Impact:
These findings challenge assumptions about MAR risks and underscore the complexity of outcomes.
Project C: Parent–child relationships
We used the UK Millennium Cohort Study to evaluate adolescent-parent relationships via self-reports from both groups.
Key findings:
- No significant differences in parent–child closeness between MAR and non-MAR families.
- Contrary to earlier concerns, no evidence of overprotectiveness or heightened conflict in MAR families during adolescence.
Impact:
The results provide reassurance regarding the psychosocial dynamics of MAR families and have informed family psychology and social policy debates.
Dissemination and outreach:
Findings were published in top journals (JAMA, Demography, IJE, PDR) and presented at leading conferences (Population Association of America, ESHRE, EPC). We also hosted a final dissemination workshop. Throughout the project we engaged with the media to broaden public understanding.
MARTE has made major conceptual, empirical, and methodological contributions to the study of medically assisted reproduction (MAR) and its impact on families.
Causal evidence using population-wide data
Prior studies often relied on small, selective, cross-sectional samples. MARTE employed national registers from Finland, Sweden, and Norway, using advanced causal inference methods—such as sibling and individual fixed-effects—to isolate MAR effects from confounders like subfertility and socio-economic status. This is a major methodological advance.
Broadening from early-life to life-course outcomes
Research had previously focused the childhood period. MARTE expanded this to cognitive, educational, and mental health outcomes into adolescence and adulthood.
Inclusion of unsuccessful MAR and adult outcomes
Most literature overlooked adults whose MAR treatments failed. We documented lasting effects of unsuccessful MAR on mental health and relationship stability, offering evidence to support more inclusive counselling.
Sociological integration
MARTE went beyond medical framings by considering social stratification. We showed how socio-economic background both masks and magnifies differences.
Cross-national comparative insights
Despite contextual differences, key patterns—like better education but worse mental health among MAR children—were consistent.
Expected outputs
We have published 20 papers, with more under review or in preparation. Findings have been shared at international conferences, a final dissemination event, and through media and blogs.
Future impact includes:
- Policy and clinical guidance: Continued engagement with practitioners and policymakers to inform counselling and MAR provision.
- Data and infrastructure: Code shared with collaborators for future research
- Scientific leadership: The project’s widely cited outputs and interdisciplinary appeal (across public health, economics, sociology) have led to invitations for presentations/keynotes.
Causal evidence using population-wide data
Prior studies often relied on small, selective, cross-sectional samples. MARTE employed national registers from Finland, Sweden, and Norway, using advanced causal inference methods—such as sibling and individual fixed-effects—to isolate MAR effects from confounders like subfertility and socio-economic status. This is a major methodological advance.
Broadening from early-life to life-course outcomes
Research had previously focused the childhood period. MARTE expanded this to cognitive, educational, and mental health outcomes into adolescence and adulthood.
Inclusion of unsuccessful MAR and adult outcomes
Most literature overlooked adults whose MAR treatments failed. We documented lasting effects of unsuccessful MAR on mental health and relationship stability, offering evidence to support more inclusive counselling.
Sociological integration
MARTE went beyond medical framings by considering social stratification. We showed how socio-economic background both masks and magnifies differences.
Cross-national comparative insights
Despite contextual differences, key patterns—like better education but worse mental health among MAR children—were consistent.
Expected outputs
We have published 20 papers, with more under review or in preparation. Findings have been shared at international conferences, a final dissemination event, and through media and blogs.
Future impact includes:
- Policy and clinical guidance: Continued engagement with practitioners and policymakers to inform counselling and MAR provision.
- Data and infrastructure: Code shared with collaborators for future research
- Scientific leadership: The project’s widely cited outputs and interdisciplinary appeal (across public health, economics, sociology) have led to invitations for presentations/keynotes.