Some moms-to-be pledge to have an epidural upon arrival at the hospital, while others hope to experience labour and birth without using this method of pain relief. Regardless of which camp you're in, it's worth knowing that while the epidural can be a useful tool, it does have a downside, too. Arming yourself with the facts will help you make an informed decision when labour unfolds.
Before we delve into the pros and cons, however, here's how the procedure is done: An anaesthesiologist inserts a needle between two vertebrae in the lower back, stopping just short of the sac enclosing the thick cable of nerves (spinal canal) inside the spine. A fine catheter is threaded through the needle, which is then removed. Next, a mixture of local freezing agent and morphine-like medication is piped in through the tube, causing numbness below the waist.
Read more: Strategies for an easier labour>
“Sunny-Side up” baby If the cervix is fully dilated, but your baby won’t budge because she’s facing your belly button instead of your backbone, using an epidural to relax the muscles of the vagina and perineum sometimes provides just enough wiggle room to allow her to rotate and descend.
Exhaustion If contractions keep you awake for a long time, a nap (made possible by getting rid of the pain) can give you a second wind.
Hypertension During labour, high blood pressure (which can further soar during pushing) poses dangers, including a small risk of stroke. A common benefit of epidural — a drop in blood pressure — can reduce these risks.
Need for forceps or vacuum An epidural prevents discomfort if your baby needs help making an entrance.
Non-emergency C-section An epidural allows mom to remain awake during the birth. (The speed of general anaesthesia is only needed in very urgent situations, which account for a small minority of C-sections.)
Read more: C-section recovery>
Did you know that epidurals don’t always work as advertised? Roughly five to 10 percent of the time, an epidural only provides patchy, partial relief — for instance, numbing only one side of the lower body. Adding more medication or redoing the epidural corrects the problem roughly 75 percent of the time. If you’re expecting a pain-free labour, this can be extremely disappointing. At the other end of the spectrum, occasionally the freezing extends too high, which can make breathing difficult. Other potential drawbacks include:
Limited mobility Most epidurals keep you more or less immobile. But even if the resulting numbing is light enough to allow you to move your legs (a type of epidural that’s only available in a handful of hospitals) in most centres, you’ll automatically be hooked up to an IV and a fetal monitor, so you won’t be able to walk the halls or move around.
Less effective labour and pushing ability This side effect can not only lengthen labour, but can substantially increase the likelihood of a forceps or vacuum delivery. (By how much? Some doctors say around 38 percent, while others assert epidurals double or even triple the odds.) As well, more than half of women who get an epidural will need the hormone oxytocin (which has its own risks) to strengthen slowed or stalled contractions.
Read more: Long labour survival guide>
Under certain circumstances, can double the odds of C-section The good news? According to Klein, it’s possible to reduce, or even eliminate this extra risk by holding off on an epidural until being four to five centimetres dilated, and asking for a high-dose regimen should you need oxytocin. Most Canadian hospitals still give doses too low to make a dent in the added C-section risk. (Klein notes that this is an area of extreme controversy and other obstetricians and anaesthesiologists may dispute his assertions.)
Drop in mom’s blood pressure This can cause the baby’s heart rate to slow down. Since this is sometimes a sign of distress, if IV fluids and drugs don’t bring it back to normal, a C-section is usually the next step.
Difficulty urinating An epidural increases the chance you’ll need to have a catheter inserted to empty your bladder.
Spinal headache Approximately one percent of women who get an epidural develop a headache, which may come on during or after labour, and can be very severe. An epidural-like procedure can fix the problem, but if not, the pain can linger for days or (rarely) weeks.
Perineal injury Tears and other injuries are more common in women who use epidurals because they increase the risk of a vacuum or forceps delivery.
Fever For reasons that aren’t completely understood, epidural significantly raises the odds of developing a fever during labour. In one study from the year 2000, nearly 12 percent of women who received an epidural ran a temperature of 37.8 C or greater, versus only 0.2 percent of those who didn’t use this type of anaesthesia. In case the fever signals infection, typically mom and baby are both treated (often unnecessarily) with antibiotics. The baby may also be admitted to the NICU for close observation.
Our experts: -Tracy Franklin, registered midwife, Toronto
-Michael C. Klein, childbirth researcher, family physician, senior scientist emeritus at The Child & Family Research Institute and professor emeritus at the University of British Columbia, Vancouver
-Andrew Kotaska, researcher and obstetrician, Yellowknife
A version of this article appeared in our Pregnancy Winter 2012/2013 issue with the headline "Should you have an epidural?," pp. 49.