Objective: To characterize the range of symptoms experienced by pregnant methadone-maintained (MM) and buprenorphinemaintained (BM) women to determine whether these differ from those experienced by a control group of nonopioid exposed pregnant women. Opioid-maintained (OM) patients report high rates of symptoms related to direct opioid effects and withdrawal. Pregnancy is associated with a range of symptoms, some overlapping with opioid effects and withdrawal. Methods: Prospective, nonrandomized, open-label comparison study undertaken in a large teaching maternity hospital in South Australia. Pregnant BM(n=25),MM(n=25) and nonopioid exposed controls (n=25) were recruited and matched for age, parity, gravidity, alcohol consumption, and smoking status. Symptom report patterns, maternal withdrawal, and additional substance use were assessed. Results: MM women reported 10 and BM women reported 2 symptoms throughout pregnancy at rates greater than controls.Methadonemaintained women reported significantly (P < 0.05) more symptoms than BM women compared to controls throughout pregnancy. Methadone-maintained women reported 8 and BM women reported 3 symptoms in the third trimester at rates greater than controls. Methadone-maintained women reported greater opioid withdrawal than controls; this did not occur in BM women. Additional substance use was comparable between BM and MM women but greater than controls. Conclusions: Patterns of symptom reports may have clinical implications for maternal and fetal health during pregnancy for OM women including optimization of opioid dosing regimens, education regardingmaternal nutritional intake and preventing postnatal depression, thereby ensuring maternal health and fetal development during pregnancy and enhancing mother-infant bonding and healthy child development postnatally.