Premature births can be better understood through a study of fast-evolving genes, according to a study by researchers at the Vanderbilt University School of Medicine.
The study led by Dr. Louis Muglia looks at the evolutionary impact with genes involved in birth timing evolving fast to make the birth event less risky for the mother and the child. Consequently, the gestation period in humans is the shortest among primates and mammals.
The researchers compared the genomes of human, chimps, rhesus monkey, macaque monkey, cow, dog, rat and mouse. They isolated150 fast-evolving genes.
Next, they studied how 9000 variants of these genes, called SNPs (single-nucleotide polymorphisms) were associated with preterm birth in humans.
300 Finnish women were analysed and the researchers concluded that a gene that codes for the receptor for follicle stimulating hormone (FSH) influenced human pregnancy. African American women too showed a similar pattern.
This was an unexpected finding because FSH's connection with labour had not been established.
"This is a gene we would not have identified thinking about classic physiology of birth timing," says Muglia. Further study is necessary to see if the association is found in larger populations and to try and work out how this gene can influence birth timing.
If a further study establishes an association, it could lead to a genetic screening test that would help in identifying women at risk of preterm birth. This could lead next to development of drugs to prevent preterm birth.
The study has not been entirely accepted by Australian birth expert Professor Roger Smith from the Hunter Medical Research Institute in Newcastle, who states, "I think the most exciting thing from it is the idea of looking for the cause of preterm birth by comparing the evolutionary development of humans with other primates. I think that's exciting and novel."
Nevertheless, he is sceptical about whether the findings in themselves will give a huge advance in our understanding of preterm birth.