It's well known that strong rhythmic contractions of the uterus are needed to allow the baby's head to dilate the cervix. However little was known about what controls these contractions until now.The groundbreaking research from Monash University, the Royal Women's Hospital and the Hunter Medical Research Institute, show that a potassium ion channel called hERG in the uterus is responsible.
Acting as a powerful electrical brake, hERG works during pregnancy to suppress contractions and prevent premature labour. However, at the onset of labour a protein acts as a switch to turn hERG off, removing the brake and ensuring that labour can take place.
The team, led by Professor Helena Parkington from the School of Biomedical Sciences at Monash University, found that in overweight women the switch doesn't work, failing to turn hERG off.
"We've known for years that women who are overweight are much more likely to experience complications during pregnancy and labour -- but we didn't know why," Professor Parkington said.
"Pinpointing the mechanism is a major breakthrough, not only does it ensure a smooth pregnancy, but knowing when contractions kick in at more or less the right time, is crucial to our understanding of the labour process."
Image: C-section prep, via Shutterstock