Answer: Usually restrictions like no sex or lifting etc are prescribed to women who have placenta previa (placenta covering their cervix) and or those who experience blood loss due to a low lying placenta. But rest assured, as you doctor may tell you, there is a very high chance that a low lying placenta will be higher at a later scan. In your third trimester (until around 36 weeks) the bottom part of your uterus does most of it’s growing and stretching, taking the placenta with it. It doesn’t ‘migrate’ upwards, but being attached to the uterine wall, it’s carried upwards with it. In 0.5% of cases, the placenta doesn’t move up with the uterus – so given that small percent, there is an extremely good chance that your placenta will not be covering your cervix when it’s time to give birth, enabling you to have a vaginal birth. If you have a low lying placenta at 18-20 weeks, this does not mean you need a caesarean section. The placenta will highly likely be further away from the cervix at the end of your pregnancy. In your first and second trimesters, the uterus still has much growing to do, so an ultrasound late in your third trimester (after the uterus has finished growing) will give you and your doctor or midwife a better picture of what’s really going on – and if it really a matter of concern.