Between weeks 13 and 27, your spine carries a load it has never carried before, and the ache that shows up is mechanical, not mysterious. The uterus clears the pelvic brim, your center of mass moves forward, and the muscles along your lower back work overtime to keep you upright. At Cadence Chiropractic in American Fork and Spanish Fork, second trimester care focuses on keeping the pelvis and lumbar spine moving evenly while that shift happens, using low-force adjustments with no twisting or popping. Most women who start prenatal care in this window come in for one of three complaints: a dull lower back ache, one-sided hip or buttock pain, or a sharp catch when rolling over in bed.

What changes in your spine between weeks 13 and 27?

Three things change at once: the lumbar curve deepens, the sacroiliac joints absorb more uneven load, and the abdominal wall stretches until it can no longer brace the spine the way it used to.

Around week 12 the uterus rises above the pelvic brim, and by roughly week 20 it reaches the navel. Weight gain accelerates alongside it. ACOG and the National Academy of Medicine recommend about one pound per week during the second and third trimesters for women who began pregnancy at a normal BMI, with 25 to 35 pounds total. Because that weight sits in front of the spine rather than over it, the lumbar joints and the muscles behind them multiply the effort required to stay balanced. Research by Whitcome and colleagues published in Nature in 2007 found the human female lumbar spine has evolved specific adaptations for this forward load, including additional wedged vertebrae compared with males.

The abdominal wall changes too. Diastasis recti, a widening of the gap between the two halves of the rectus abdominis, is already common mid-pregnancy. A study of first-time mothers published in the British Journal of Sports Medicine in 2016 found 33.1 percent had measurable separation at gestation week 21. Less abdominal bracing means the low back and pelvis handle more of the work.

Why does back pain usually begin in the second trimester instead of the first?

The hormone story is only part of it. Relaxin, which increases ligament laxity, rises through the first 14 weeks and then gradually declines between weeks 14 and 24 before holding steady, according to serum measurements published in Acta Obstetricia et Gynecologica Scandinavica. Laxity is already in place before most second trimester pain starts. What changes is the load. Looser joints plus a rapidly growing forward weight is what tips a comfortable body into a symptomatic one, usually somewhere between weeks 18 and 24.

How does Cadence Chiropractic adjust care for a second trimester body?

Care changes in three practical ways: positioning, technique, and what we assess.

Positioning. After about 20 weeks, lying flat on the back can compress the inferior vena cava and reduce blood return. Prenatal patients are positioned side-lying or on pregnancy-specific tables with abdominal support.
Technique. The Activator Method uses a small handheld instrument to deliver a precise, measured force. There is no twisting, rotation, or cracking involved.
Assessment. The Webster Technique is a specific sacral analysis and adjustment defined by the International Chiropractic Pediatric Association. It addresses sacral misalignment and the tension in the round and sacrouterine ligaments that attach to the uterus. Our doctors are certified in it at both offices.

A first visit runs 45 minutes to an hour and includes history, examination, and a care plan. Follow-ups typically take 15 to 20 minutes. Initial visits generally range from $100 to $150 and follow-ups from $55 to $75. We accept Select Health, Blue Cross Blue Shield, United Health, and UMR, and no referral from your OB or midwife is required.

What can you do at home between visits?

Sleep on your side with a pillow between your knees to keep the pelvis level overnight. Hinge at the hips rather than rounding the low back when lifting a toddler or loading a dishwasher. Avoid standing on one leg while getting dressed, since that loads one sacroiliac joint at a time. Take short, frequent walks instead of one long one. Skip deep crunches and anything that makes your midline dome outward.

When should you call your OB or midwife first?

Call your prenatal provider before booking a chiropractic visit if you have vaginal bleeding, leaking fluid, regular contractions before 37 weeks, fever, severe one-sided abdominal pain, sudden leg weakness, or any change in bladder or bowel control. Those symptoms need medical evaluation, not an adjustment.

Second trimester back pain responds well to care because the cause is usually a change in mechanics rather than damage. Cadence Chiropractic serves expecting mothers throughout Utah County with gentle, pregnancy-specific care in American Fork and Spanish Fork. Book an evaluation and we will build a plan around your trimester, your symptoms, and your comfort level.