According to one review that looked into the complaint, low-back pain affects more than two-thirds of women during pregnancy.
Back pain can also arise near the center of the back when doctors call it lumbar pain, or the tailbone when they refer to it as posterior pelvic pain.
Many factors, including hormonal and postural changes, contribute to back pain during pregnancy. The causes vary between women and may depend on the stage of pregnancy.
This article discusses the reasons for pregnancy-related back pain, and ways to treat and prevent this discomfort.
Causes in the first trimester
Factors that can lead to back pain during the first trimester include hormonal changes and stress, as we discuss below.
High levels of progesterone in the first trimester can affect the stability and alignment of the joints.
During the first trimester, levels of progesterone in the body increase rapidly. High levels of this hormone help relax the muscles and ligaments near the pelvis, which can affect the stability and alignment of the joints.
Another hormone that doctors call relaxin helps the egg to implant in the uterus wall, and also prevents contractions during the early stages of pregnancy. As labor nears, relaxin stimulates the cervix to soften and open in preparation for delivery.
Furthermore, relaxin relaxes the ligaments and joints in the pelvic region so that the birth canal can expand during delivery.
Finally, relaxin affects the ligaments that stabilize the spine, which can cause instability, postural shifting, and low-back pain.
Although many consider pregnancy an exciting life event full of changes, it also introduces new sources of stress.
Causes in the second and third trimesters
During the second and third trimesters, the uterus continues expanding as the fetus grows rapidly.
Postural changes, weight gain, and muscle separation all contribute to back pain in the later stages of pregnancies, as we discuss below:
A woman's center of gravity shifts to the front of the body as the baby grows in weight.
Some women may lean back to regain balance. Leaning backward puts extra strain on the back muscles that can lead to low-back pain and muscle stiffness.
Weight gain during pregnancy can contribute to low-back and joint pain.
Weight a person gains during pregnancy can contribute to low-back and joint pain.
The amount of weight a woman puts on during pregnancy can impact her and her baby's overall health.
The Centers for Disease Control and Prevention (CDC) recommend that women carrying a single fetus gain the following amount of weight, according to their pre-pregnancy weight:
- 28–40 pounds (lb) if underweight
- 25–35 lb if a healthy weight
- 15–25 lb if overweight
- 11–20 lb if obese
The abdomen consists of two parallel bands of muscles that connect in the middle of the abdomen. These muscles help to stabilize the spine and support the back.
During pregnancy, the growing fetus pushes against the abdominal muscles, causing them to stretch and, in some cases, separate. This pressure can result in a condition called diastasis recti.
During the second and third trimesters, some women may develop a bulge or "pooch" in their stomach. This is a sign that their abdominal muscles are separating to allow room for the growing uterus.
As the abdominal muscles stretch, they become weaker. This can increase a woman's risk of injuring her back or developing low-back or pelvic pain.
How to relieve pain
Strengthening the back muscles with pregnancy-friendly exercises can help reduce back pain.
At times, it may seem like back pain is inevitable during pregnancy. However, there are ways to relieve back pain both during and after pregnancy.
Ways to relieve back pain during pregnancy include:
- regularly stretching the lower back
- sleeping on the side with a pillow between the legs and below the abdomen
- using a warm compress to relax tight muscles or reduce inflammation
- making postural changes, such as standing and sitting upright, so the back is straight and shoulders square
- wearing a maternity belt for extra abdominal and back support
- using a lumbar pillow for additional back support while sitting
- getting prenatal massages to relax tight muscles, improve range of motion, and relieve stress
- using alternative treatments, such as acupuncture and chiropractic services, with a practitioner who specializes in pregnancy.
- reducing stress through meditation, prenatal yoga, and other mindfulness techniques
- getting enough sleep
Tips for preventing and avoiding pain
There are several effective ways to avoid back pain during pregnancy, including:
- strengthening the back muscles with pregnancy-friendly exercises
- maintaining a healthy weight throughout pregnancy
- doing gentle exercise regularly, with a doctor's approval
- wearing flat- or low-heeled shoes with arch supports
- avoiding standing for long periods
- avoiding lifting too much weight
- practicing proper lifting techniques by squatting down and using the legs instead of the back
- practicing good posture
- avoiding sleeping on the abdomen
When to see a doctor
Women who experience back pain during pregnancy should contact their obstetrician or other healthcare providers if they experience the following symptoms:
- severe pain
- pain that lasts more than 2 weeks
- cramps that occur at regular intervals and gradually intensify
- difficulty or pain when urinating
- a tingling sensation in the limbs
- vaginal bleeding
- irregular vaginal discharge
Sciatica occurs as a result of an injury or irritation to the sciatic nerve. Sciatica during pregnancy occurs when the growing fetus puts pressure on the sciatic nerve.
One symptom of sciatica is low-back pain that radiates through the buttocks and down the leg.
Women who suffer from severe back pain that persists longer than 2 weeks should discuss treatment options with their healthcare provider.
Women who are pregnant should speak with their healthcare provider before starting any new medications, supplements, or naturopathic treatments.
Back pain is a common part of pregnancy. Several factors can cause back pain during pregnancy, including:
- increase in hormone levels
- postural changes
- weight gain
- muscle separation
- stress on the body
Pregnancy-related back pain usually resolves on its own after giving birth. Severe back pain that lasts longer than 2 weeks may require medical treatment or physical therapy.
Women should speak with their healthcare provider before starting any new medications or treatments while they are pregnant.