I have been taking Singulair for a rather long time (7 years or so). Singulair has been the only medication that is good for me when I have asthma and seasonal allergies. I can not do without it a day. The drug decreases swelling and inflammation, which impede passing air through breathing passages. It also relaxes walls of bronchioles letting more air to pass. No other drug could facilitate my state in the period of acute condition of the disease. A year ago I realized that I was pregnant. It was the happiest occasion in my life. The only upsetting thing was my conjecture that I would not be able to take Singulair during pregnancy. I know that many other asthma medications are contraindicated during carrying a baby. However I decided to consult my doctor. To my luck it turned out that Singulair is not expected to be hazardous to a health of an unborn baby. I took Singulair during my pregnancy and gave a birth to a healthy child. Of course I had some of Singulair side effects (weakness, fatigue, dizziness), but they are nothing in comparison with its positive effect. I now breastfeed and have not interrupted taking Singulair. It is good that due to Singulair I was able to bear a child without much discomfort for myself.