There is no evidence that sexual intercourse will precipitate either miscarriage or preterm labour of a healthy pregnancy, single or twin. If a miscarriage or preterm labour does happen, it is very unlikely that this was caused by love making. It is much more likely that any apparent association was simply an unhappy coincidence. Having said that, if you have any vaginal bleeding (or, later, signs of preterm labour), your doctor or midwife may well recommend that you avoid full intercourse for a specific time (ask how long!). Intercourse may also be counselled against once your waters break, since the risk of infection is then increased. It is true that intercourse may appear to ‘bring on’ labour – but this is usually only true if labour is due to start within a few days, in any case.We are not sure if this is due to physical pressure on the cervix, the effect of prostaglandins in semen, or the release of oxytocin during orgasm or nipple stimulation. However, these factors only seem to have an effect once the uterus is ‘primed’ for labour – usually (all being well) sometime after 37 weeks.I hope this helps to put your mind at rest. Please do discuss any specific concerns with your midwife or doctor.