Examining the myometrial transcriptome in twin pregnancy

One in 10 babies are born too soon (preterm). However, in twins this is more than 50% who are born preterm. This research study has tried to find out why so many women who are pregnant with twins have a preterm labour, which sadly can lead to severe health problems for the babies and worry for their parents. Working alongside doctors and patients from Liverpool Women’s Hospital, researchers have been looking at the uterus (womb) in twin pregnancy and why it might be triggered to contract early. They have focused on looking at differences in genes, which are the parts of your DNA that carry the instructions to tell the cells of your body, or in this case the cells of the uterus, how to behave.

Researchers aimed to identify which genes were there (expressed) and if the level of expression of these genes was different in the uterus of women with twins compared to the uterus from women carrying only one baby. This would help to give an idea about how the uterus was behaving before the babies were born and may help identify women at most risk of preterm birth, or which treatments would be most suitable to give to women with twins experiencing preterm labour to stop contractions.

Researchers used small samples (biopsies) of the uterus which were given to them from women having caesarean section deliveries, either preterm or full term, and performed a large investigation into all of the genes which were present. Surprisingly, when they compared the genes from the uterus of women with one baby to those with twins, they found very few differences, suggesting that their wombs are very similar. When they examined for differences between the wombs from women with one baby delivering preterm and women with twins at full term however, they found quite a few differences. Researchers think this might be due to the extra stretch on the womb from having two babies at full term compared to one baby preterm. More research on the effect of stretch on the uterus needs to be done to better understand if, and how, this could be contributing to preterm birth in twins, and ultimately, they hope to make the outcome of pregnancy and birth happier for many more women and their families when twins are born preterm.

This study was carried out by Dr Andrew Sharp at Liverpool Women’s Hospital, and was funded by the Twins Trust and BMFMS research bursaries.