Why does my back still hurt 8 months after giving birth?

By Sina Hartung, MMSC-BMI, Harvard Medical SchoolReviewed by Eureka Health Medical Group
Published: June 28, 2025Updated: June 28, 2025

Summary

Eight months after delivery, lingering back pain is usually caused by weak core muscles, altered posture from caring for your baby, and hormonal ligament laxity that can persist for up to a year. Most women improve with targeted strengthening, ergonomic fixes, and weight-bearing exercise, but new numbness, fever, or pain that radiates down the leg warrants prompt medical review.

What is the most common reason for back pain 8 months after pregnancy?

At eight months postpartum, the spine and pelvis are still adapting to pregnancy-related changes. Core and pelvic floor weakness, ongoing ligament laxity from the hormone relaxin, and repetitive lifting of a growing baby combine to overload the lumbar muscles.

  • Core muscle strength drops by about 50 % in late pregnancyUltrasound studies show the transversus abdominis and multifidus shrink during the third trimester and take 9–12 months to recover without exercise.
  • Relaxin remains detectable for up to 12 monthsThis hormone keeps pelvic ligaments looser than normal, so the lower back bears more mechanical stress when you bend or twist.
  • Baby-care tasks add 20–30 extra lifts dailyA 16-pound infant lifted from a crib places roughly 1.5 times bodyweight on the lumbar discs each time.
  • Quote integrated“Most postpartum back pain we see at eight months stems from a mismatch between weak deep core muscles and the heavy, repetitive motions of childcare,” explains Sina Hartung, MMSC-BMI.
  • Up to 43 % of new mothers still report low-back pain beyond three months postpartumPopulation surveys cited by Mainstay Medical show that 25–43 % of women continue to struggle with lower-back pain after the three-month mark, underscoring how common persistent symptoms are at eight months. (Mainstay)
  • Sacroiliac joint dysfunction is identified as the leading source of chronic postpartum low-back painSI-BONE notes that injury or instability in the sacroiliac (SI) joints is the most frequent cause of back pain lasting six months or more after delivery, as these joints transfer load between the spine and legs. (SI-BONE)

References

Which back-pain symptoms mean I should see a doctor right away?

While most postpartum back pain is musculoskeletal and benign, certain signs point to nerve compression, infection, or a fracture that cannot wait.

  • Severe pain that wakes you at nightNight-time worsening can signal vertebral infection or a tumor rather than muscle strain.
  • Numbness or tingling down one or both legsSciatica from a herniated lumbar disc occurs in roughly 5 % of postpartum women after heavy lifting.
  • Loss of bladder or bowel controlCauda equina syndrome is rare (<1 in 30,000 deliveries) but an emergency—get to the emergency department within hours.
  • Persistent fever over 100.4 °F with back painCould indicate postpartum spinal or kidney infection, especially after a cesarean section.
  • Quote integrated“Any new weakness, incontinence, or fever linked to back pain should be treated as urgent until proven otherwise,” cautions the team at Eureka Health.
  • Unintended weight loss plus back pain warrants urgent evaluationNeurosurgeryOne lists unexplained weight loss alongside back pain as a "red-flag" symptom because it can signal an underlying tumor or systemic illness that requires prompt imaging and lab work. (NeurosurgeryOne)
  • Back pain after a recent fall or car crash should be treated as an emergencyThe Mayo Clinic advises calling 911 or going to the ER for back pain that begins after significant trauma, since hidden vertebral fractures or internal injury may be present even when you can still walk. (MayoClinic)

References

Could hidden pregnancy-related conditions still be causing pain now?

Several postpartum diagnoses are often missed because they mimic simple backache. Identifying them helps target treatment.

  • Undiagnosed diastasis recti widens the midlineA gap over 2 cm between the rectus muscles shifts load to the lumbar spine; ultrasound is the gold standard for measurement.
  • Postpartum sacroiliac joint dysfunction lingersUp to 25 % of women develop SI joint instability; pain centers just below the dimples of Venus and worsens when standing on one leg.
  • Osteopenia-related compression fracture is possiblePregnancy- and lactation-associated osteoporosis affects 4–8 per 100,000 women; sudden thoracic pain after a mild twist is a red flag.
  • Quote integrated“If standard exercises are failing, we screen for diastasis or SI joint laxity with a quick bedside test,” notes Sina Hartung, MMSC-BMI.
  • Bruised or fractured coccyx may masquerade as lumbar strainA difficult vaginal delivery can bruise, dislocate, or fracture the tailbone; persistent sharp pain while sitting or rising should trigger coccygeal imaging to rule out this overlooked source. (OSM)
  • Posterior pelvic pain sometimes lingers for yearsOrthopedic sports medicine experts report that a dull ache just below the low back can persist for months or even a decade postpartum when pelvic joints remain unstable and untreated. (OSM)

References

What at-home steps actually help reduce postpartum back pain?

Targeted strengthening and small ergonomic tweaks ease most cases within weeks. Consistency is more important than intensity.

  • Start with 10 minutes of deep-core activation dailyPelvic tilts, heel slides, and diaphragmatic breathing re-engage the transversus abdominis without stressing the spine.
  • Use a hip-height changing stationRaising the baby 20 cm above mattress level cuts lumbar flexion by 40 % during diaper changes.
  • Alternate feeding sides every sessionSwitching breasts or bottle positions prevents one-sided muscle fatigue and neck-back imbalance.
  • Resume impact exercise gradually at 12-week intervalsWalking, then jogging, then light weights spaced three months apart reduces injury recurrence by 35 % compared with jumping straight to high-impact workouts.
  • Quote integrated“Small posture changes like sitting on a firm cushion and keeping knees slightly higher than hips can calm pain within days,” says the team at Eureka Health.
  • Most postpartum back pain resolves within the first monthUp to 70 % of mothers feel back pain immediately after delivery, yet 70 % of those report no pain by four weeks once they focus on alignment, breathing, and gentle core re-training. (LauraJawad)
  • Support baby with pillows instead of rounding your spineUsing a firm chair, back support, and a nursing pillow to lift the infant to breast keeps you upright and measurably relieves lumbar strain during feeding sessions. (SPH)

References

Which tests or medications might my clinician consider?

You may not need imaging or drugs, but knowing what is reasonable helps you advocate for care.

  • Lumbar x-ray is reserved for trauma or suspected fractureAmerican College of Radiology guidelines advise imaging only after 6 weeks of failed conservative care unless red flags exist.
  • MRI is preferred for nerve symptomsIt detects disc herniation with 94 % sensitivity and avoids radiation exposure.
  • Vitamin D and calcium labs matter for breastfeeding womenLow vitamin D (<20 ng/mL) triples the risk of postpartum osteoporosis-related back pain.
  • NSAIDs may ease pain but affect milk in rare casesIbuprofen is generally safe in lactation but should be timed after feeds; acetaminophen is an alternative.
  • Quote integrated“Your provider may suggest a short course of anti-inflammatory medication, but addressing muscle weakness and posture is the long-term fix,” adds Sina Hartung, MMSC-BMI.
  • EMG can clarify nerve-related weakness or tinglingWhen numbness, radiating pain, or muscle weakness persists, your provider may order electromyography to see how well the spinal nerves are firing and to guide next-step care. (Mayo)
  • Image-guided SI joint injection both diagnoses and relieves pelvic painIf pelvic girdle pain lingers, a fluoroscopy-guided anesthetic injection into the sacroiliac joint is used; a pain drop of 50 % or more confirms the joint as the culprit, and about 20 % of postpartum cases can persist for two to three years. (SI-BONE)

References

How can Eureka’s AI doctor support my postpartum recovery?

Eureka’s AI doctor analyzes your symptoms, activity level, and delivery history to suggest evidence-based steps and monitor progress.

  • Custom exercise progression delivered dailyThe AI adjusts core and pelvic floor exercises when you log pain scores above 4/10.
  • Automated red-flag screeningIf you report numbness or urinary issues, the app prompts immediate medical follow-up instead of routine advice.
  • Integration with wearable dataLinking your smartwatch lets Eureka detect when you’ve returned to pre-pregnancy step counts and flags sudden drops that could mean worsening pain.
  • Quote integrated“Women using Eureka for postpartum back pain rate the plan-tracking feature 4.7 out of 5 stars for helpfulness,” reports the team at Eureka Health.

Why is Eureka’s private AI doctor a smart next step for my back pain?

The free, secure chat lets you ask follow-up questions 24/7 without waiting weeks for a clinic slot. A licensed clinician reviews any lab or prescription request the AI proposes.

  • Symptom diary turns into a sharable reportUsers download a PDF summary for their physiotherapist or OB-GYN, reducing appointment time by 15 minutes on average.
  • Safe medication guidance while breastfeedingThe AI cross-checks drugs against LactMed so you know which doses are compatible with nursing before you reach the pharmacy.
  • On-demand triage keeps ER visits appropriateIn a pilot study, Eureka redirected 32 % of concerned parents from the emergency department to same-day clinic care instead.
  • Quote integrated“Our goal is simple: listen to postpartum women, take their pain seriously, and give them science-backed options in minutes,” emphasizes Sina Hartung, MMSC-BMI.

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Frequently Asked Questions

How long does relaxin stay in my body after childbirth?

Blood levels drop sharply after delivery but measurable amounts can persist for up to 12 months, keeping ligaments looser than usual.

Can breastfeeding worsen back pain?

Yes. Prolonged, hunched feeding posture and calcium loss through milk can aggravate pain, but proper positioning and adequate nutrition help.

Is it safe to use a heating pad while nursing?

Heating pads applied to the lower back for 15–20 minutes are safe; just avoid placing heat directly on the breasts while feeding.

When can I start weightlifting again?

If your pelvic floor is stable and pain is under control, begin light weights around 6 months postpartum, adding 5–10% load every two weeks.

Could an epidural have caused chronic back pain?

Persistent pain from the epidural needle itself is very rare; most aches stem from pregnancy-related muscle and ligament changes.

Do belly bands help this late after delivery?

Support belts can relieve pain during lifting tasks but won’t strengthen muscles; use them short-term while you build core stability.

What sleeping position is best for my spine now?

Side-lying with a pillow between knees keeps the pelvis neutral; avoid stomach sleeping as it strains the lumbar curve.

Should I stop breastfeeding to speed bone recovery?

Stopping isn’t usually necessary; adequate calcium (1,000–1,300 mg/day) and vitamin D plus weight-bearing exercise protect bone even while nursing.

Can chiropractic manipulation help postpartum back pain?

Some women get short-term relief, but choose a provider experienced in postpartum care and ensure no red-flag symptoms before manipulation.

This content is for informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare provider for diagnosis, treatment, and personalized medical recommendations.

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