Many types of medications can ease pain during labor and delivery. Ideally, the drugs used are safe for mother and baby, don't interfere with labor and delivery, and provide good pain relief with few side effects.

This is a guide to medications used during labor and delivery. Work with your health care team to make the best decision for you and your baby.

An epidural block can be given in the labor room. Block placement usually isn't painful, although there might be some discomfort from numbing the skin before the block. Small tubes (epidural catheters) placed in the low back allow a pump to drip pain medicine into the lower body.

A test dose might ensure the epidural is in the right place. It takes up to 15 minutes for the medication to take effect, depending on the type of anesthetic used.

Your health care provider will discuss with you the best time to ask for an epidural during labor — either soon after your labor starts or as labor goes on. You might not be able to have an epidural if you have had major surgery in your lower back, have low blood-clotting factors, have an infection in your lower back or are on certain blood thinners.

Pros

An epidural eases most pain in the lower body without slowing labor much. You remain awake and alert, but you still feel pressure and some stretching during delivery. The epidural's effect on the baby is minimal to none. A combined spinal-epidural block relieves pain faster than a regular epidural and might use less medication.

Cons

In a few instances, epidurals might not provide enough pain relief. An epidural can decrease blood pressure. There's a small risk that the drop in blood pressure could slow the baby's heart rate. Other possible side effects include fever, itchiness or back soreness after giving birth. A bad headache is a rare side effect.

Some women with an epidural can't walk during labor.

A spinal block is typically used to block pain during a C-section. However, a spinal block can be used to relieve pain if delivery is expected shortly or if forceps or vacuum extraction is needed.

During a spinal block, the medication is injected into the fluid below the spinal cord in the lower back. It takes effect quickly. It can provide only a couple of hours of pain relief. A spinal block given during epidural placement is called a combined spinal-epidural block.

Pros

A spinal block provides complete pain relief in the lower body for about an hour or two. You'll remain awake and alert.

Cons

A spinal block might decrease blood pressure. Infrequently, this can slow the baby's heart rate. Side effects include itching or back soreness after delivery. A rare side effect is a bad headache.

Opioids can be used to lessen pain during labor. They can be injected into a muscle or given through an intravenous (IV) catheter.

Pros

Opioids can help you relax. Most take effect within minutes.

Cons

Opioids don't offer great relief from labor pain. They typically don't work for pain during delivery. They can cause nausea, vomiting and drowsiness. These drugs can affect the newborn's breathing and cause the baby to be drowsy, which might hamper the first breastfeeding.

A local anesthetic might be used to quickly numb the vaginal area to prepare for an incision to make the opening of the vagina bigger (episiotomy) or repair a tear after delivery. The drug is injected into the area around the nerves that carry feeling to the vagina, vulva and perineum.

A pudendal block is a type of local anesthetic injection that might be used shortly before delivery to block pain between the vagina and anus (perineum). It can also be used to relieve pain during the repair of a tear after delivery. The local anesthetic is injected into the vaginal wall near the pudendal nerve and takes effect in 10 to 20 minutes.

Pros

Local anesthetics temporarily numb a specific area. Negative effects for mother and baby are rare.

Cons

Local anesthetics don't relieve the pain of contractions. An allergic reaction is possible. Rarely, they can produce a toxic reaction, affecting your central nervous system or heart.

Nitrous oxide — an odorless, tasteless gas — is a pain reliever that's inhaled. You give yourself the gas using a hand-held face mask. Nitrous oxide takes effect within a minute.

Pros

Nitrous oxide can be used on and off or continuously during labor. You control the amount you use. You'll be able to walk during labor. If you become too drowsy, you won't be able to hold the mask to your face and you'll stop inhaling the anesthetic.

The effects quickly wear off when you take off the face mask. Nitrous oxide is believed to have little effect on the baby.

Cons

Nitrous oxide doesn't eliminate pain. For relief, it's necessary to breathe in the nitrous oxide about 30 seconds before each contraction. It might cause nausea, vomiting, dizziness and drowsiness.