Last COST ISO1405 meeting was held in October 2017 in Florence, the capital of Italy’s Tuscany region, well renowned for the countless master pieces of Renaissance and architecture.
One of the objectives of Working Group One is to assess patterns of epigenetic changes that might be associated with different labour and birth events and may affect early and late health. In view of paucity of studies in this area of research, epigenetic interactions which may take place as a result of medical interventions and environmental exposures remain elusive including the consequences thereafter on both the mother and child (Dahlen et al. 2013).
Oxytocin, many times referred to as the love hormone, is a vital component of a comprehensive neurochemical system that empowers the body to adjust to exceedingly emotional circumstances (Carter and Porges, 2013). It is implicated in several physiological and pathological mechanisms and plays a pivotal role in childbirth and lactation (Kim et al. 2017). Epigenetics refers to the study of heritable changes in gene function that takes place without a change in the DNA sequence. In most cases, these modifications turn genes on or off, permitting or stopping the gene from protein synthesis. Epigenetics encompasses DNA methylation, histone modifications through acetylation, methylation or phosphorylation and genomic imprinting. MicroRNAs have also been implicated in regulating DNA methylation and histone modifications (Roman et al. 2014). Epigenetic changes through DNA methylation in somatic cells which happen early in the fetal life may carry life-long consequences in terms of pathological processes linked to them. The latter offers the rationale for researching DNA methylation in order to establish such links (Dolinoy, Weidman and Jirtle, 2007).
Our review is focusing on the physiology (release and effects) of endogenous oxytocin of both the mother and the baby and explore the effects of interventions such as pain relief (epidural), caesarean section and use of exogenous oxytocin (Syntocinon®) in induction and augmentation of labour. We are investigating how these interventions influence sensory information from the uterus with consequence effects on the stress system and the release of endogenous oxytocin in both short and long term perspective. Some epigenetic changes have been shown to occur including DNA methylation of the oxytocin receptor. Therefore, one of the aims of the present review is to analyse whether there is a connection between the neuroendocrinology and epigenetic modulation or whether they are two separate systems.
Moreover, two other members of Working Group One are working on an existing list of longitudinal cohort studies that they began developing in the COST Bergen Meeting 2016. The list if currently being amended and extended to include a definitive list of cohort studies from around the world that includes intrapartum information in their standard data collection. Notable cohorts included so far are the Avon Longitudinal Study of Parents and Children (ALSPAC), Lifelines (Netherlands) and Advancing Maternal and Child Health in Romania (the MAIA study).
However, it is emerging that although many of these are child and/or mother cohort studies, they do not contain sufficient intrapartum information. It is intended for a summary report to be written once a final list has been collated that will be a basis for future big data and follow up studies, with an aim to highlight the need for intrapartum measurement in cohort studies.
Carter, C.S. & Porges, S.W. (2013). The biochemistry of love: An oxytocin hypothesis. European molecular biology organization. 14 (1), 12-16. doi: 10.1038/embor.2012.191.
Dahlen, H.G., Kennedy, H.P., Anderson, C.M., Bell, A.F., Clark, A., Foureur, M., Ohm, J.E., Shearman, A.M., Taylor, J.Y., Wright, M.L., & Downe, S. (2013). The EPIIC hypothesis: Intrapartum effects on the neonatal epigemone and consequent health outcomes. Medical Hypotheses, 80 (5), 656-662. doi: 10.1016/j.mehy.2013.01.017
Dolinoy, D. C., Weidman, J. R., & Jirtle, R. L. (2007). Epigenetic gene regulation: Linking early developmental environment to adult disease. Reproductive Toxicology, 23(3), 297-307. doi: 10.1016/j.reprotox.2006.08.012
Kim, S.C., Lee, J.E., Kang, S.S., Yang, H.S, Kim, S.S., & An, B.S. (2017). The regulation of oxytocin and oxytocin receptor in human placenta according to gestational age. Journal of Molecular Endocrinology, 59(3):235-243. doi: 10.1530/JME-16-0223.
Roman C, Dafashy T, Hedge S, Ashimi O, Bytautiene E. (2014). Epigenetics modifications of pre-eclamptic placenta: A systematic review. Obstetrics and Gynecology, 4:233. doi: 10.4172/2161-0932.1000233.