Intravenous/Intramuscular Labor Pain Relief

Pain-relieving medications injected into the bloodstream may alleviate, but not eliminate, pain during labor.

These are medications that are given either intravenously (through an IV) or intramuscularly (with an injection) to decrease labor pain and are usually ordered by the obstetrician or midwife and administered by the nurse.

Opioids for Pain Relief

Opioids have a long history of use in obstetrics for the relief of labor and delivery pain. Although there are a great number of narcotics available today, only a few are commonly used for childbirth. They include meperidine (Demerol®), morphine, fentanyl, butorphanol (Stadol®) and nalbuphine (Nubain®).

These medications enter the bloodstream and allow you to better tolerate the pain of labor and delivery, although they do not normally provide complete pain relief. The amount of relief from these medications does vary, but they can take the "edge" off the pain and make your labor more tolerable

The vast majority of women who do not have a regional anesthetic for labor will opt for one of these medications, which can be taken prior to receiving an epidural or spinal anesthetic.

Patient-Controlled Analgesia

If the medications ordered by the obstetrician are not enough to provide satisfactory pain relief, the anesthesiologist can arrange for these medications administered via an intravenous infusion pump that you control. This method of administration pain relief is called patient-controlled analgesia, or PCA.

With this option, you are provided with a button that can be activated whenever you desire pain relief. The pump is programmed to push a certain (set) amount of medication into your system. You have control over how much medication you need depending on how much discomfort you are experiencing from your contractions.

The anesthesiologist and your nurse will monitor the intravenous medications that you are administering. The PCA pumps are programmed so that you cannot take too much of the medication.

Side Effects

A major disadvantage of IV medications is that they can make you drowsy and sleepy. In addition, there may be other side effects that include nausea, vomiting, decreased respirations, itching, constipation and urinary retention.

Effect on the Baby

Narcotics will cross the placenta and enter the baby's circulation. As a result, the baby may show some side effects. In utero, the baby's heart rate may change slightly in pattern. But there is no known long-term effect due to this change in heart rate pattern.

The baby has the ability to metabolize the medications, but it does so more slowly than the mother. After the baby is born, the baby may be slightly sleepy. Again, it is unlikely that the baby will be affected adversely as a result of small amount of mother's medication, but it is important to realize that the medication does impact the baby.

Seeing an effect of the mother's medication in the baby may be dependent on the dosing of medication in relation to the time of birth. If the baby has adequate time to break down the medication, only a minimal effect may be seen.

Learn more about Brigham and Women's Hospital

For over a century, a leader in patient care, medical education and research, with expertise in virtually every specialty of medicine and surgery.

About BWH