At the University of Wales College of Medicine, Cardiff, informal chats over coffee between a group of disparate researchers - psychiatrists/genetic epidemiologists, developmental and health psychologists interested in the behavioural adjustments of in vitro fertilisation (IVF) families - gave birth to an idea for a novel approach to the ages-old nature-nurture debate. "It suddenly came to us that children born by IVF differ in terms of genetic relationship to their parents," says Anita Thapar, Professor of Child and Adolescent Psychiatry in the Department of Psychological Medicine. "IVF children can be genetically related to both parents, one parent only, or neither if there is surrogacy. The differing degrees of genetic relatedness provides a unique opportunity to disentangle genetic and intrauterine influences - and we had all the necessary expertise and contacts between us to put together this study."

Traditionally, the genes versus environment debate has focused on the interplay of genetics and environmental factors - upbringing, parental influences, exposure to infections and so on. In adoption studies, for example, similarities between adopted children and biological parents are assumed to be due to shared genes, whereas similarities with nonbiological parents are put down to shared environment.

This overlooks the fact that adopted children have spent nine months in the womb of their biological mother, which may have had a significant influence on their development. A mother's smoking, for example, or poor nutrition before birth would have affected the developing baby. But the situation is even more complicated than that: the mother's behaviour in pregnancy may have been influenced by her genes - perhaps predisposing her to depression or anxiety.

With twin studies, there are other complications. Unlike nonidentical twins from different eggs, some identical twins share a placenta and therefore share the intrauterine environment to a much greater extent than others with separate placentas.

The Cardiff study, funded through a Showcase award, will look at a minimum of 45 families of children born by IVF in 1996 and 1997 for each conception group (standard IVF, surrogacy, sperm, egg or embryo donation). The families will be identified through more than ten IVF clinics, with whom health psychologist Dr Jacky Boivin has long-standing links.

Families who agree to take part in the study will answer anonymous questionnaires put together by developmental psychologists Dr Gordon Harold and Professor Dale Hay, to gather information on behaviours and environmental factors.

Professor Thapar feels that since there have been no methodological developments for several years, this new approach could make a valuable contribution to the field. "This study makes use of a new population, as well as a new method, and it allows the effects of intrauterine environment to be separated from genetic effects for the first time."

The project is primarily a feasibility study - to find out whether the method works, and whether families would be willing to participate in further research. "On the last page of the questionnaires, we ask whether they'd allow us to look at birth and antenatal records, which allow us to make an independent assessment of risk factors such as smoking or alcohol during pregnancy, pregnancy and birth complications and whether they would be willing to release their name and address. We also ask if they are willing to have face-to-face assessments, or medical assessments, such as blood-pressure checks or cholesterol levels, since there's a lot of interest in the relationship between cardiovascular diseases and early uterine environment."

The new method, if successful, will complement rather than replace existing methods such as twin or adoption studies. "The key thing with genetic epidemiological research is to get convergence of findings from different types of study designs - because each of them are going to have different patterns of strengths and weaknesses - and then you can be more confident about the result," explains Professor Thapar. "It's really exciting, and if it works, it should be applicable across a whole range of psychiatric genetics and other areas of medicine as well for epidemiological and genetics research."

See also

• Showcase: Awards for Innovative Research

External links

• Professor Anita Thapar at the University of Wales College of Medicine Cardiff: Research interests
• University of Wales College of Medicine Cardiff

Further reading

Recommended by Professor Thapar
Rutter M, Pickles A, Murray R and Eaves L (2001). Testing hypotheses on specific environmental causal effects on behavior. Psychological Bulletin. 127, 291-324

Rutter M and Silberg J (2002). Gene-environment interplay in relation to emotional and behavioral disturbance. Annu. Rev. Psychol. 53: 464-90

Thapar A, O'Donovan M C (2002). Neurogenetics. In: Biological Psychiatry. Volume 1. Eds: H D'haenen, J A den Boer, Willner P. p167-180. John Wiley & Sons Ltd: London

Recommended by Dr Boivin
Boivin J and Kentenich H (Eds) (2002). Guidelines for counselling in infertility. ESHRE Monographs: Oxford University Press.

Boivin J (in press). In vitro fertilization. Encyclopaedia of the Human Genome: Nature Publishing Group

Boivin J, Scanlan L and Walker S M (1999). Why are infertile couples not using psychosocial counselling? Human Reproduction, 14: 1384-1391.

Boivin J, Andersson L, Shoog-Svanberg A, Hjelmstedt A, Collins A and Bergh T (1998). Psychological reactions during in vitro fertilization (IVF): Similar response pattern in husbands and wives. Human Reproduction, 13: 3262-3267.

Recommended by Dr Harold
Harold G T, Shelton K H, Goeke-Morey M C and Cummings E M (in press). Assessing relations between interparental conflict, child emotional security, and adjustment in the context of interparental conflict. Monographs of the Society for Research in Child Development.

Harold G T and Hay D F (2002). Normal development in middle childhood. Psychiatry, 1(5): 3-6.

Rice F, Harold G T and Thapar A (2002). The genetic aetiology of childhood depression: A review. Journal of Child Psychology and Psychiatry, 43(1): 65-79.

Thapar A N, Harold G T and McGuffin P (1998). Life events and depressive symptoms: Shared genes or shared adversity? A research note. Journal of Child Psychology and Psychiatry, 39 (8): 1153-1158.

Harold G T and Conger R D (1997). Marital conflict and adolescent distress: The role of adolescent awareness. Child Development, 68, 333-350.

Harold G T, Fincham F D, Osborne L N and Conger R D (1997). Mom and Dad are at it again: Adolescent perceptions of marital conflict and adolescent psychological distress. Developmental Psychology, 33 (2): 333-350.