Back Pain During Pregnancy: Causes & Relief

A dull, aching, or sharp back pain during pregnancy is one of the most common complaints among expectant mothers. By various estimates, 50 to 70% of pregnant women experience it, and most of the time it's a normal response to carrying your baby rather than a sign of something dangerous.

In this article we'll look at why your back and lower back hurt during pregnancy, how ordinary muscle pain differs from pelvic pain and sciatica, how to safely ease the discomfort at home and — most importantly — when back pain should prompt you to contact your doctor right away.

Why your back and lower back hurt during pregnancy

Back pain during pregnancy is almost always explained by natural changes in the body. Usually several causes are at work at once:

• The hormone relaxin. It softens the ligaments and joints of the pelvis, preparing your body for birth. But along with the pelvis, other joints “losen” too, so your back becomes less stable and is more easily overloaded.
• A shifting center of gravity. Your growing belly pulls your body forward. To keep your balance, you instinctively lean back and arch your lower back more — and the back muscles end up working overtime.
• The growing uterus. As it expands, it presses on blood vessels and nerves in the lower back and pelvis and changes your posture.
• Separating abdominal muscles. The straight (rectus) abdominal muscles stretch and pull apart (diastasis), support the spine less well, and the load shifts onto the back.
• Weight gain. The extra pounds mean extra strain on your muscles and spine.
• Posture and habits. Standing for long stretches, sitting in an awkward position, carrying heavy things, and high-heeled shoes all make the pain worse.

Sometimes the lower back aches as early as the first few weeks, and many women wonder whether back pain is an early sign of pregnancy. Mild lower-back discomfort can indeed show up in the early weeks because of hormonal changes, but on its own it's an unreliable sign — only a test and your doctor can confirm a pregnancy.

What back pain can feel like: lower back, pelvis, and the sciatic nerve

Women describe completely different sensations under the umbrella of “back pain.” Understanding which type you have helps you choose the right relief.

Lower back (lumbar) pain

The most common type. You feel it in the center and along the sides of the lower back, at waist level or just above. It gets worse toward evening, after long periods of standing, sitting, or exertion. It feels like the “ordinary” lower back pain you may have had before pregnancy. Sometimes it radiates into the upper back too — upper back pain in pregnancy often comes from your changing posture and growing breasts.

Pelvic pain (pain in the pelvis and sacrum)

This is called pelvic girdle pain, and when the discomfort is concentrated at the front, around the pubic bone, it's known as symphysis pubis dysfunction. It hurts below the waist — in the sacrum and buttocks, sometimes radiating into the thighs and the perineum. It flares when you turn over in bed, climb stairs, get up from a chair, or stand on one leg (for example, while putting on trousers). This pain happens because relaxin loosens the pelvic joints.

Sciatica (pinched sciatic nerve)

If pain from your lower back or buttock shoots down the back of your leg, sometimes all the way to the foot, and comes with numbness or tingling, that looks like sciatica. True sciatic nerve compression during pregnancy is less common than people think — more often the “shooting” comes from tense pelvic muscles. At night, leg discomfort is also easy to confuse with cramps; we cover those in a separate article on leg cramps during pregnancy.

When back pain starts and how it changes by trimester

Back pain can appear at any stage, but it most often builds as your belly grows — between the fifth and seventh month.

• First trimester. A mild pulling in the lower back from hormonal changes. Sharp lower-back pain combined with abdominal pain or unusual discharge needs your doctor's attention.
• Second trimester. Your belly grows and your center of gravity shifts, and lower-back pain often makes itself known for the first time.
• Third trimester. The peak “back” period. Your weight is at its highest, your body is actively preparing for birth, and relaxin levels are at their peak. Back pain in the third trimester is a very common complaint. Late in pregnancy it's important to tell familiar muscle pain apart from rhythmic pain that comes in waves — the latter could be contractions.

How to relieve back pain during pregnancy at home

The good news: in most cases back pain can be noticeably eased with simple measures at home.

Watch your posture

Stand tall with your shoulders back, and don't “hang” on your lower back. When sitting, use a chair with a backrest and tuck a small cushion behind your lower back. Don't stand for long stretches; if you have to, rest one foot on a low step and switch feet.

Choose comfortable shoes

Swap high heels and completely flat soles for comfortable shoes with good arch support. It takes a noticeable load off your back.

Sleep on your side with a pillow between your knees

In the second half of pregnancy it's more comfortable and safer to sleep on your side, ideally the left. A pillow between your knees aligns your pelvis and takes the strain off your lower back, and another one under your belly helps too. We go into comfortable positions in more detail in our article on how to sleep during pregnancy.

Warmth and warm water

A warm (not hot) shower, a heating pad, or a warm compress on your lower back relaxes the muscles. Avoid hot baths, and don't apply heat to your belly.

Gentle movement and stretching

Your muscles need rest, but complete stillness only makes the pain worse. Regular gentle exercises help — for example, the “cat-cow”: on all fours, slowly round and then arch your back. Walking, swimming, and dedicated prenatal classes are good too. If a particular movement makes the pain worse, stop doing it.

Maternity support belt and massage

A supportive maternity belt lifts your belly and takes some of the load off your back — especially in the third trimester. A gentle back massage from a therapist who works with pregnant women also eases the tension.

What about pain relievers

Don't take pain relievers on your own. During pregnancy, anti-inflammatory drugs from the NSAID group (such as ibuprofen) are usually avoided, especially in the second half of pregnancy. Acetaminophen (paracetamol) is often considered the more preferable option, but the need for any medication, its dose, and how long to take it should be discussed with your doctor.

How to prevent back pain

• Keep up light physical activity — strong back and abdominal muscles support the spine better.
• When picking something up off the floor, squat down using your legs rather than bending from your back, and don't carry heavy loads.
• Gain weight gradually, within the range your doctor recommends.
• Don't sit or stand in one position for too long — change your position often.
• Sleep on your side, on a medium-firm mattress.

Back pain often goes hand in hand with other pregnancy “discomforts” — for example, swelling and heaviness in the legs. Overall body care, movement, and comfortable support help with all of them at once.

When to worry: back pain that means you should see a doctor right away

An aching back on its own usually isn't dangerous. But there are warning signs that mean you should contact your doctor or call emergency services:

• Severe or sharp pain that won't go away or came on suddenly.
• Rhythmic pain that comes in waves at regular intervals, especially with pressure low in your belly: before 37 weeks this can be a sign of threatened preterm labor, and at full term it may be the start of labor. To learn how to recognize it, read our article on how to tell that labor has started.
• Back pain with a fever, chills, or pain and burning when you urinate — this may be a kidney infection, which needs prompt treatment during pregnancy.
• Back pain together with vaginal bleeding or spotting.
• Back pain together with severe pain low in your belly — to learn what's normal here and what isn't, read our article on lower abdominal pain during pregnancy.
• Pain after a fall, blow, or injury.
• Numbness or weakness in your legs, or loss of control over your bladder or bowels — rare but serious signs.

When in doubt, it's better to call your doctor. It's far more reassuring to ask and hear that everything is fine than to worry on your own.

Key takeaways

• Back and lower back pain during pregnancy is very common and usually not dangerous.
• The causes include the hormone relaxin, a shifting center of gravity, the growing uterus, separating abdominal muscles, weight gain, and posture.
• Pain can be lumbar, pelvic (symphysis pubis dysfunction), or sciatica-type — relief is matched to the type.
• Good posture, comfortable shoes, sleeping on your side with a pillow between your knees, warmth, gentle exercise, a support belt, and massage all help.
• Take any medication only after checking with your doctor; NSAIDs are usually avoided during pregnancy.
• See a doctor urgently for severe or rhythmic pain, fever, bleeding, an injury, or numbness in your legs.

This article is for general information only and is not a substitute for individual medical advice. For back pain or any worrying symptoms, contact your own doctor or midwife.