IV pain medications (intravenous) are given through an IV (small plastic tube) that is placed in a vein in your arm. There are a variety of different IV pain medications your doctor can prescribe, each having different risks and benefits. Some of the most common are: fentanyl, morphine, hydromorphone, meperidine, and remifentanil. IV pain medications can be given throughout labor. IV pain medications aren’t given immediately before the delivery of the baby because they cross the placenta and may make the baby sleepy or have trouble breathing.