Inclusion Criteria:  Subjects that will be included in the prospective cohort group:  individuals at least 18 years of age at least 28 weeks gestation (third trimester) on medication-assisted treatment for opioid use disorder, including methadone or suboxone.  Patients who will be included in the control group:  individuals at least 18 years of age at least 28 weeks gestation (third trimester) have not been on been on opioids in the past 12 months.  Exclusion Criteria:  Those who are unable to participate in informed consent discussions, Unable to give informed consent for any reason, Not fluent in English (surveys are validated in English language) Unable to participate fully in all study procedures for any reason including sensory deficits, scar tissue, or infection at any QST sites.