What are some ways to prevent a miscarriage in women? No sex?

Sex when pregnant doesn’t increase the risk of miscarriage, but we usually advise women who are bleeding in the early part of pregnancy (a ‘threatened miscarriage’) not to have sex until the bleeding has stopped; if more bleeding follows after sex it just adds to the anxiety of the situation. A woman who’s had two or more miscarriages needs testing to look for a cause, by a Reproductive Endocrinology and Infertility or REI specialist if you’re trying again, or an OB doctor if you’re already pregnant.