Medications To Provide Pain Relief And Assist Labor
Most women in the United States receive pain-relieving medications during labor. The size of your hospital (a small community vs. a large academic or teaching hospital) can affect the choices available for pain relief, but most hospitals can accommodate your needs. An anesthesiologist — a doctor who is an expert in pain relief — may work with your doctor to pick the best method for you.
Medications are also available to speed up (augment) your labor, or induce (start up) your labor. The following are commonly used techniques and medications to relieve pain (analgesics and anesthetics) or assist your labor during childbirth (oxytocics).
Analgesics are used for pain relief, without total loss of physical sensation or feeling. Although they generally won't always stop pain completely, analgesics do lessen it. Narcotic analgesics such as meperidine (Demerol) are frequently used to relieve the pain of labor. They are usually given by injection into a muscle or vein and generally do not prolong or delay contractions of well-established labor.
Narcotics may produce such side effects as nausea, vomiting, a slow breathing rate and decreased blood pressure. Some other common narcotic preparations are designed to provide pain relief with less risk of slowing the breathing rate. Examples include Nubain and Stadol.
If born soon after a mother receives any narcotic, a baby's rate of breathing may also be slower than normal at birth. But this effect generally is short term and can be reversed with anti-narcotic medication such as naloxone.
These medications are given by injection during labor to numb you, but not put you to sleep. Anesthetics can be given by one of several commonly used techniques:
Epidural anesthesia. The most common type of anesthesia used for pain relief during labor, epidural anesthesia is injected through a catheter in the epidural space, the space between the dura mater (the sheath surrounding the spinal cord) and the bony vertebrae of your spine, numbing your body from the waist down. An anesthesia specialist carefully guides a small plastic tube (catheter) into this space. Catheter placement takes 5 to 20 minutes. The medication is then injected through the catheter. It takes about 3 to 5 minutes to work and provides complete relief in about 85% of women, partial relief in 12% and no relief in 3%. It can also be used for cesarean section, but the strength and amount of medication used are greater than those used for labor and vaginal birth.
Before receiving an epidural, you'll need intravenous fluids to prevent your blood pressure from dropping — the most common side effect of this form of anesthesia. The epidural catheter remains in your back during labor so medication can be given to keep you pain-free. It can remain in place for a short time after vaginal or Cesarean delivery for postpartum pain relief.
An epidural uses intermittent boluses or repeated doses of medication given every 1 to 2 hours as needed during labor and delivery. Medication can also be delivered continuously in lower doses, known as a continuous low-dose epidural, which has several advantages. A small amount of medication continuously flows through the epidural catheter at a rate controlled by an infusion pump so that pain relief will be less likely to wear off during your delivery. Continuous epidural numbs your sensation but may have less effect on the motor power of your legs.
Another form of epidural is patient-controlled epidural anesthesia (PCEA). PCEA allows you to control your own pain relief. With a push-button device, you release controlled amounts of drug when you need it. The PCEA device only releases a certain amount of medication over time so you won't overmedicate yourself. Some studies have shown that PCEAs use less medication than standard and continuous epidurals, are less likely to lower blood pressure, yet provide more effective pain relief.
Potential side effects of all epidurals include mild to severe postpartum headache, difficulty urinating or walking after delivery, or abnormally elevated body temperature. Because the epidural provides numbness and pain relief from your waist down, it can prolong your labor or diminish your ability to push out your baby, leading to use of a vacuum or forceps to help deliver your baby. Epidural medications can temporarily slow the baby's heartbeat because these drugs can lower blood pressure.
Sometimes your blood pressure falls during epidural anesthesia, and it may be associated with a temporary slowing of the baby's heart rate. If this happens, treatment of your blood pressure (with fluids or medication) will almost always fix the problem.
Spinal anesthesia. This type of anesthesia, known as "a spinal," is used as an alternative to epidural or general anesthesia when cesarean delivery is needed. It is not generally used during labor. However, it would be the anesthesia of choice if a woman needed a cesarean section and did not have a working epidural block. Spinal anesthesia is injected through the same space that an epidural is injected. However, the injected medicine goes directly into the fluid surrounding the spinal cord (rather than just outside the sac containing the fluid as done for an epidural). During the procedure, there is close monitoring of the mother's vital signs including blood pressure, breathing rate, pulse and blood oxygen levels. Headache may occur after a spinal but usually resolves after 24 hours.
Medicines To Start (Induce) Or Assist (Augment) Labor
There are many reasons why patients and providers may decide to start (induce) labor rather than waiting for it to begin on its own, including concerns both mother's and baby's health. Among the reasons for inducing labor are prolonged pregnancy, also called post-term or post-dates pregnancy; high blood pressure that antedates pregnancy or develops as a complication of pregnancy (pregnancy induced hypertension or preeclampsia); diabetes mellitus; previous stillbirth; intrauterine growth restriction; and premature rupture of membranes (the bag of water breaking before the start of contractions). Of course, all women whose labor is induced are expected to have a vaginal delivery (not cesarean delivery).
The same medicine used to induce labor may also be used to augment labor if contractions seem not to be coming frequently or strongly enough.
Oxytocics may be used to induce or augment labor. The most commonly used is an intravenous medication called oxytocin (Pitocin), which is pumped slowly into the vein by an infusion pump. It's a synthetic version of a hormone that helps to start contractions and also helps to release your breast milk during breastfeeding. Pitocin is ordered to help contractions begin if there aren't any or to increase the frequency of contractions when fewer occur naturally.
Some women report that medications used to induce labor cause contractions that feel stronger than those that occur naturally. The dose of oxytocin is adjusted to provide contractions that are strong and frequent enough to cause the cervix to dilate but not so strong or frequent to prevent relaxation between contractions. Relaxation is needed to assure that a fetus receives sufficient oxygen during the course and progress of labor. If the pattern of the fetal heart rate tracing suggests that not enough oxygen is being transferred, the Pitocin dose may be reduced or stopped.
Prostaglandins are medicines formulated either as gels or tablets that may be place in the vagina or, for tablets, given by mouth to help with the process of inducing labor. Prostaglandins work to both soften and dilate ("ripen") the cervix, as well as to stimulate contractions. As with oxytocin, patients require monitoring after prostaglandins are used. Many health professionals avoid using prostaglandins to induce labor in women who have had a prior cesarean delivery out of concern that such use may increase the risk of complications.