PETS is a study of twins, from when they were in the womb through to childhood and beyond. The study aims to identify what makes us all who we are; our health, development and well being. Where better to start than with twins, who share the same mother, but are usually in their own ‘sac’ during pregnancy, then share the same home environment as children. Despite this, even ‘identical’ twins can have different personalities, physical characteristics and illnesses. Why is this?

Study Summary
Study name The Peri/Post-natal Epigenetic Twins Study
Study abbreviation PETS
Current principal investigator/s A/Professor Jeff Craig
Dr Richard Saffery
Current project manager Pamela Leong
Primary institution Murdoch Children’s Research Institute
Collaborating institution/s University of Melbourne
Deakin University
Australian Institute of Family Studies
LaTrobe University
Royal Women’s Hospital
Mercy Hospital for Women
Monash Medical Centre
Major funding sources National Health and Medical Research Council
Bonnie Babes Foundation
Sigrid Juselius Foundation
Academy of Finland
Finnish Cultural Foundation
Financial Markets Foundation for Children
Victorian Government’s Operational Infrastructure Support Program
Study website
Key reference for study (published study protocol) Saffery, R., Morley, R., Carlin, J.B., Joo, J.H.E., Novakovic, B., Andronikos, R., Ollikainen, M., Li, X., Loke, Y.J., Carson, N., Wallace, E.M., Umstad, M.P., Permezel, M., Galati, J. and Craig, J.M. (2012). Cohort Profile: Peri/postnatal Epigenetics Twins Study. International Journal of Epidemiology, 41, 55-61.

Loke Y.J., Novakovic B., Ollikainen M., Wallace E.M., Umstad, M.P., Permezel M., Morley R., Ponsonby A.L., Gordon L., Galati J.C., Saffery R. and Craig J.M. (2013) The Peri/Postnatal Epigenetic Twins Study (PETS). Twin research and human genetics: the official journal of the International Society for Twin Studies, 16, 13-20.

Are data available to others outside study team? Yes, with custodian approval
Study focus (e.g. social development) Investigating whether epigenetic marks measured at birth and early life can provide clues to the causal links between intrauterine exposures influencing perinatal phenotype and the risk of chronic diseases later in life.
Sampling frame Women attending multiple pregnancy clinics at 3 Melbourne (Australia) hospitals (Royal Women’s Hospital, Monash Medical Centre, Mercy Hospital for Women) who were 18-22 weeks gestation
Study type (e.g. randomised control trial, cohort, case-control) Longitudinal pre-birth cohort study
Year commenced 2007
Ongoing recruitment? No
Commencement sample (N) 250 twin pairs and mothers
Intergenerational (e.g. offspring)? No
Imaging (e.g. fMRI, ultrasound, retinal photograph)? Ultrasound data including Doppler
Linkage (e.g. BioGrid, VPDC, NAPLAN, Medicare)? No
Biosamples (e.g. buccal, blood, hair)? Blood
Cord blood
Newborn screening (Guthrie) card
Placenta (sample)
Umbilical cord (sample)
Ethics approvals or requirements (e.g. specific, extended, unspecified, other)? This project only (Specific consent)
Future research related to this project (Extended consent)

Study Coordinator

Jane Loke, PhD

Ph: + 61 3 9936 6263

Study Associates

Professor Jeff Craig

Ph: + 61 3 5227 8655

Professor Richard Saffery

Ph: + 61 3 8341 6341