Premature births could be associated with the evolution of the species

Posted on April 16, 2011

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Pregnant woman

My two younger cousins are both having a baby – by some strange coincidence their wives have become pregnant around the same time. That’s one way to avoid sibling rivalry. As wonderful as the news is, it puts me yet again in the “why is she not married and with child?” spotlight. The recession it seems, is the perfect time to have a child; unless of course you’re me and have opted to hit the books and not the sack. One leading supermarket says it’s seen a hike in pregnancy tests by 30 per cent in the last two years, which could spell a baby boom.

Women these days have so many options on how they want their unborn child delivered: caesarean; water-birth; natural birth – con gas or sin gas – for some they can even pin-point their due date. One national newsreader, who shall remain anonymous, remarked to a friend: “…..Can’t stop now love. I’m going for a manicure and then I’m having my baby at 4.” If only everything could run like clockwork. The reality is there are still a large number of babies who are born prematurely and the reason why has baffled the medical world.

A group of scientists believe premature births could be down to genes. My older brother decided he’d had enough womb-time and showed up several weeks early. It was nice of him to be so keen, but he was then forced to sit out the real world experience in an incubator until he was well enough. I on the other hand, was punctual, and yes of course I’m being smug!

A study by the Royal College of Obstetricians and Gynaecologists published in PLoS Genetics has looked at why so many women go into early labour and why it often happens to members of the same family. In the UK, one in 10 babies is born before the 37th week of pregnancy, with potential problems for their health.

The researchers’ theory was that human premature birth is associated with the evolution of the species. The authors note that human beings have bigger heads and narrower birth canals than most other primates and mammals. Scientists at Vanderbilt University, Washington University and the University of Helsinki, believed the genetic variants could be the product of a failed evolutionary attempt at making child-birth easier by making it happen sooner, so babies would be smaller.

They looked at which genes show more variation in their DNA sequence in humans than in other primates (chimpanzees and monkeys) and narrowed it down to 150 genes. They then compared those 150 genes in 328 Finnish mothers, some of whom gave birth prematurely.

The researchers found many of the women who went into early labour had variants in their follicle stimulating hormone receptor (FHSR) gene,which is a hormone receptor that helps estrogen develop in the follicle, which contains a woman’s egg.

This is still very early research and some experts say while it provides promising material to understanding how genetic and environmental factors can contribute to how human births work; as the old adage goes, timing is everything and that may be something we never fully understand.

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