DURATION of pregnancy has been linked with chemical DNA changes in newborns and may direct future understandings in the care of premature infants. A study of the umbilical cord blood of more than 6,000 newborns in Sweden has identified DNA methylation changes in thousands of genes, with increasing changes for each week of pregnancy.
Research undertaken by the Karolinska Institutet, Stockholm, Sweden, aimed to contribute to the understanding of epigenetics in preterm delivery and health outcomes in premature babies. Epigenetics assesses the links between genes, environment, and health, and has directed research into ageing, obesity, asthma, and allergy.
The study incorporated contributions from 26 studies across the international Pregnancy and Childhood Epigenetics (PACE) consortium. Previous PACE studies demonstrated DNA changes occurring in newborns that were associated with maternal smoking and assessed the effects of air pollution.
Epigenetic processes control fetal development and growth. DNA methylation is a factor in these epigenetic processes and can affect gene activation and protein formation. Most DNA methylations present at birth do not remain into childhood, however 17% of these changes persist to adolescence. “Now we need to investigate whether the DNA changes are linked to the health problems of those born prematurely,” says Prof Erik Melén, Karolinska Institutet.
Premature birth, defined as occurring before 37 weeks of pregnancy, accounts for 5–10% of births worldwide and is linked to neurodevelopmental and ocular disorders and respiratory disease. Greater rates and severity of these disorders and diseases occur in babies born more prematurely. Mapping epigenetic changes to the timeline of pregnancy may provide insight into developmental origins of health and disease.
Prof Melén believes this research may help direct future care in premature birth. “We hope that our new findings will contribute valuable knowledge about fetal development, and in the long term new opportunities for better care of premature babies to avoid complications and adverse health effects.”