Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes. Although there are no studies on birth defects in humans, problems have not been reported. However, some studies in animals have shown that theophylline can cause birth defects when given in doses many times the usual human dose. Because your ability to clear theophylline from your body may decrease later in pregnancy, your doctor may want to take blood samples during your pregnancy to measure the amount of medicine in the blood. This will help your doctor decide whether the dose of this medicine should be changed.
Theophylline crosses the placenta.
Use of this medicine during pregnancy may cause unwanted effects, such as fast heartbeat, irritability, jitteriness, or vomiting, in the newborn infant if the amount of medicine in your blood is too high. Ephedrine has been shown to cause birth defects in humans when used during the first trimester. Phenobarbital taken during pregnancy has been shown to increase the chance of birth defects in humans. Also, taking phenobarbital regularly during the last 3 months of pregnancy may cause the baby to become dependent on the medicine. This may lead to withdrawal symptoms in the baby after birth.