It is safe to use insect repellents while you’re pregnant. Choose an insect repellent with up to 50% of DEET in it because that’s effective and at that level it’s safe in pregnancy. Do not be tempted to use homemade remedies, citronella oil, tea-tree oil, vitamin B1: none of those things have been proven to prevent the biting of the mosquito, so it’s very important that you use a good insect repellent and you use it properly.
Apply the insect repellent all over your exposed skin – just make sure you don’t get it in your eyes or breathe it in. You do need to reapply the insect repellent if you’ve been swimming, and if it’s very hot and humid and you’re getting quite sweaty, put another layer on then as well. Use the insect repellent on top of any sunscreen you’re using, because the smell is important to deter the mosquitoes.
And if you are using a sunscreen, you might need to use a stronger one. Putting insect repellent on top can make it less efficient, so make sure you use a sun-protection factor of between 30 and 50.
You can treat clothing with an insecticide like Permethrin which actually kills insects on contact, so you can spray clothes and you can spray bags and things that you’ve had outside as well with that mixture, and that will help get rid of mosquitoes.