Conzip can cause babies to become opioid-dependent in the womb, leading to neonatal abstinence syndrome (NAS) after birth. NAS can occur after exposure to any opioid during pregnancy, including methadone, buprenorphine, heroin, and prescription pain medications. As the substance passes through the placenta, the baby can become dependent upon it. The severity and specific symptoms of NAS depend on the amount of medication being used, how long it was used, and whether the baby was born full-term or premature. Symptoms will usually begin within one to three days after birth, but they may not appear for a week after birth in some cases. Symptoms can include excessive or high-pitching crying, increased muscle rigidity, fever, and overactive reflexes. Tremors, convulsions, poor feeding, breathing problems, sleep issues, and slow weight gain are also possible. Babies born with NAS will usually have to stay in the NICU until the symptoms subside.