Why do we need this research?
The Arabin pessary is a small, cone-shaped device that is inserted through the vagina and surrounds the cervix, giving it support. In a large, randomised trial, the pessary was shown to reduce the chances of early labour in women at high risk of premature birth who were pregnant with one baby.
As women with a twin pregnancy are at higher risk of going into early labour, it is crucial to find effective ways of keeping their babies in the womb. Recently, a Dutch study has indicated that the Arabin pessary may also work for twin pregnancies. However, another study has suggested that it does not.
The Tommy’s Centre for Maternal and Fetal Health in Edinburgh took part in the STOPPIT-2 trial; a national study that aimed to find out for sure whether the Arabin pessary can prevent premature birth in women with a short cervix who are pregnant with twins. The length of the cervix is important: if it gets too short, the risk of premature birth increases.
What happened in this project?
Women with a twin pregnancy and whose cervix was shorter than 35mm were asked to take part in the STOPPIT-2 study at 55 clinics in the UK and 1 clinic in Belgium. Over 2,000 women were scanned to check the length of their cervix, and of these, 500 received either the pessary or standard treatment (assigned at random). The researchers recorded how many women went into labour spontaneously before 34 weeks, and also looked at the health of the babies when they were born.
Unfortunately, the researchers concluded that the Arabin pessary neither prevented premature birth in women with short cervixes who were pregnant with twins, nor improved outcomes for the babies. The full results of the study will soon be published in a medical journal.
What difference will this project make?
The Arabin pessary is cheap, easy to use and appears to delay labour in women who are pregnant with one baby and at high risk of premature birth. However, we now know that the pessary does not help women with a short cervix who are pregnant with twins.