Newborn Metabolic Screening is usually done at the 24-36 hour postpartum visit and again before the 14th day of life.  You may have heard of this test as "the heel stick".  Your midwife will use a sterile lance tot collect a small amount of blood firm your newborn's heel.  Personally, I strongly encourage you to have this test done, however the state of Texas does offer parents the opportunity to opt-out of newborn testing. Newborn Screening Recommendations by State Newborn Screening is the process of testing and screening newborn babies for certain potentially dangerous conditions. If these conditions are caught at birth, the child in question can be saved from potentially disastrous consequences. For example, a lab may discover that 1 in 40,000 babies tested has an inability to break down sugars within milk. Such a child can potentially die or become retarded should they be given milk in regular quantities. By screening children for this condition at birth, one can easily avoid this consequence by changing the diet of the child. This is one of many conditions which are tested for. About Newborn Screening