The practice of urine drug testing during pregnancy and then often reporting positive results to Child Protective Services triggers a cascade that can result in separation of mother and newborn, with devastating consequence for both. These practices are more common when patients come from marginalized communities even when baseline substance use rates are the same. As our guest -- obstetrician/gynecologist and addiction medicine expert Mishka Terplan MD, MPH -- points out, illicit substances are not teratogens in comparison to, say, alcohol, tobacco or lead exposure. So why do we order these tests? He also discusses how talking with patients about substance use behaviors, especially with the help of screening instruments, is the only way to characterize substance use behaviors and formulate treatment strategies. This is the third episode in which we learn of common clinician practices in which clinicians are co-opted into punitive and even carceral systems of oppression.