A recent study investigated the association between the duration of pregnancy and DNA changes in children.
Preterm birth, also known as premature birth, defines the birth of a baby before 37 consecutive weeks of pregnancy. Globally, between five and 10 percent of children are born prematurely. Preterm birth is associated with increased risk of developing lung diseases, eye problems, and neurodevelopmental disorders.
Epigenetics is the study of changes in gene activity, caused by environmental and health factors, and does not involve alterations to the underlying DNA sequence. The epigenome, describing the chemical modifications of the DNA, plays an important role by controlling the growth and development of the fetus.
The epigenetic process known as DNA methylation affects the degree of gene activation and the amounts of a particular protein that is formed. DNA methylation patterns are associated with environmental factors linked to preterm birth such as smoking, air pollution, or maternal nutrition. Several studies indicate that DNA methylation status at birth may reflect development across the length of the pregnancy. This suggests that changes in DNA methylation may be linked to the health outcomes associated with pregnancy length.
A recent study, published in Genome Medicine, investigated the link between pregnancy length and DNA changes in children. The study was conducted within the International Pregnancy and Childhood Epigenetics (PACE) consortium. The researchers examined the associations between DNA methylation levels and the length of the pregnancy in over 6000 newborn babies from over twenty studies. They also analyzed the DNA methylation levels in older children between the ages of four and eighteen.
The study reported that DNA methylation changes in thousands of genes were identified in the umbilical cord blood in relation to the length of the pregnancy. These changes appeared to reflect the fetal development processes across the lung and brain tissues. The findings suggest that DNA changes may affect the development of fetal organs. The study also found that the majority of changes to DNA methylation at birth did not persist into childhood. In about 17 percent of the children, the DNA methylation levels were stable between birth and adolescence.
The studies, contributed by the researchers, to the PACE consortium, reported that mother’s smoking during pregnancy and air pollution led to changes in the child’s DNA. The researchers also found the DNA changes linked to aging and diseases such as asthma, obesity, and allergy. According to the study author, Dr. Melen, the next step will be to investigate whether the DNA changes are linked to the health problems associated with preterm birth.
According to the researchers, the findings may provide valuable knowledge about fetal development as well as new opportunities for better care of premature babies to avoid health complications in the long term.
Written by Ranjani Sabarinathan, MSc
References:
Merid SK, Novoloaca A, Sharp GC et al. (2020). Epigenome-wide meta-analysis of blood DNA methylation in newborns and children identifies numerous loci related to gestational age. Genome Medicine. doi: 10.1186/s13073-020-0716-9
Length of pregnancy alters the child’s DNA. (2020, March 2). Retrieved from https://www.eurekalert.org/pub_releases/2020-03/ki-lop030220.php
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