hello and welcome to healthcare magic, congrats on your pregnancy. VDRL and TPHA tests are both used to check for syphilis. The VDRL is generally done first because it is a screening test. It checks to see if certain antibodies ( chemicals that can be found in some cases in the blood) reacts with the ingredients in the test. These chemicals are released into the blood if the cells become damaged which can happen in syphilis however there are other circumstances that can cause a FALSE POSITIVE VDRL result ( the test is positive but the person does not have the disease). The conditions that cause FALSE POSITIVE VDRL results include PREGNANCY, certain viruses, lupus, rheumatic fever or rheumatic arthritis. The TPHA test would check for antibodies in the body specific to syphilis and is used as a confirmatory test. If a person had syphilis this would be positive and generally remains positive for all of the person s life. Your VDRL may have been falsely positive because of your pregnancy and the negative TPHA should be reassuring to you. You can speak to your doctor regarding any further questions. I hope the rest of your pregnancy is uneventful and that you have a beautiful healthy baby.