Nebulisers are machines that turn the liquid form of your short-acting bronchodilator medicines into a fine mist, like an aerosol. You breathe this in with a face mask or a mouthpiece. Nebulisers are no more effective than normal inhalers. However, they are extremely useful in people who are very tired (fatigued) with their breathing, or in people who are very breathless. Nebulisers are used mainly in hospital for severe attacks of asthma when large doses of inhaled medicines are needed. They are used less commonly than in the past, as modern spacer devices are usually just as good as nebulisers for giving large doses of inhaled medicines. You do not need any co-ordination to use a nebuliser - you just breathe in and out, and you will breathe in the medicine.
Pre-pregnancy, it is important to optimise control of your asthma. During pregnancy you should be closely monitored so that appropriate changes to treatment can be quickly implemented in response to any changed symptoms. In general, asthma inhalers are believed to be safe in pregnancy and the risk of harm to the foetus is much greater from having undertreated and poorly controlled asthma. Roughly one third of women find that their asthma improves during pregnancy, one third find that it stays the same, and the final third find that it worsens.