This is a stitch that is inserted into your cervix, usually at 12-16 weeks, under general, epidural or spinal anaesthetic. There are two types: MacDonald (easier to put in and take out)and Shirodkar (usually used in higher risk situations). The stitch is made of non-absorbable material and needs to be taken out at anout 36 weeks or earlier should you go into labour. Your obstetrician will only put a stitch into the cervix if you are thought to be at risk of delivering early on the basis of previous miscarriages or premature labour, or if a scan shows that your cervix is short and likely to open up as the pregnancy grows.