No. You can have sex any way you like when you’re pregnant, and it can’t do the baby any harm. The baby is completely protected inside your womb. Some women find they feel more sensitive and want to have sex more when they’re pregnant. That’s fine – the happier and more relaxed you are, the healthier your pregnancy will be!
It’s true that an orgasm can sometimes trigger an early miscarriage, but it won’t be the cause. It just sets off something that was going to happen anyway.
Also, after an orgasm your tummy might go hard and feel tight and painful. This is fine, it does no harm at all. Normally when you have an orgasm your womb contracts, but you’re not aware of it. But now you’re pregnant, it’s very obvious. It can be uncomfortable, but it’s completely harmless. It won’t cause a miscarriage or premature birth.
As the pregnancy goes on it can be uncomfortable to have intercourse with the man on top. You’ll need to find other positions, for example lying on your side with your partner behind you. Or you might just feel like having sex in other ways without having intercourse. Or not at all. Just follow your feelings.
The only times you shouldn’t have sex when you’re pregnant is if your waters have broken, if you’re bleeding, or if your midwife or obstetrician says that for a particular reason you have an increased risk of giving birth prematurely.