Tetralysal contains the tetracycline antibacterial Lymecycline which is NOT recommended for use by pregnant women. The effect on the fetus or baby will vary on the stage of pregnancy you are in when you were taking this medication. If you become pregnant while taking this medication, notify your doctor immediately as he/she needs to weigh the benefits versus the risks and might advise you to stop Tetralysal and change the medication for acne.