Growing a Baby: Supporting the Extraordinary Biomechanical Changes of Pregnancy
May 2026
Pregnancy is one of the most physically demanding and biologically sophisticated experiences the human body undergoes. In the span of nine months, the body reorganises itself at a structural level — bones shift, joints loosen, muscles lengthen and adapt, the centre of gravity moves forward, ligaments soften, and the entire architecture of the pelvis prepares for the birth of a new person. It is, by any measure, remarkable.
Chiropractic care during pregnancy is not about correcting something that has gone wrong. Pregnancy is not a problem; it is a process the body is designed for. With chiropractic we are about supporting the body that is changing and adapting biomechanically during this process and helping it remain mobile and supple. This article explores what your body is actually doing during pregnancy, why it sometimes becomes uncomfortable, and how chiropractic care, particularly the Webster Technique, may help support the body's remarkable capacity to adapt.
From the earliest weeks of pregnancy, the body begins preparing for a transformation that will continue for nine months and beyond. Much of this process is orchestrated by hormones, particularly relaxin, progesterone, and oestrogen — which work on the joints, ligaments, and soft tissues to allow the body to accommodate a growing baby and prepare for birth.
As the uterus grows forward and upward, the body's centre of gravity shifts. To compensate, the curve of the lumbar spine (lower back) typically increases — a change known as increased lumbar lordosis. This places new demands on the muscles and joints of the lower back, the sacroiliac joints, and the hips. The thoracic spine (mid-back) often adjusts in response, and these compensatory changes can extend upward through the ribcage, shoulders, and neck. The body is in a constant process of recalibration, which is both impressive and, at times, uncomfortable.
The sacroiliac (SI) joints — where the sacrum (the triangular bone at the base of the spine) meets the iliac bones of the pelvis — are among the structures most affected by the hormonal and mechanical changes of pregnancy. Under the influence of relaxin, these joints become more mobile. In most pregnancies this is entirely normal and functional. However, when the sacroiliac joints are not moving symmetrically — or when the sacrum is not positioned well within the pelvic ring — this can contribute to discomfort, reduced mobility, and a sense of instability in the lower back and pelvic area.
At the front of the pelvis, the two pubic bones are joined by a cartilaginous disc — the pubic symphysis. During pregnancy, this joint also softens and becomes more mobile in response to hormonal change. For most people this change goes unnoticed. For some, it contributes to significant discomfort, described clinically as symphysis pubis dysfunction (SPD) or as part of the broader category of pelvic girdle pain (PGP). PGP affects a significant proportion of pregnant people and can range from a mild background ache to a more limiting experience that affects walking, turning in bed, and climbing stairs.
As the uterus grows upward through the abdomen, the diaphragm is gradually displaced, and the ribcage expands laterally to accommodate the changing internal geography. This can produce discomfort in the mid-back, around the ribs, and sometimes in the upper thoracic spine. Breathing capacity may also feel altered in later pregnancy, particularly when lying flat. These are normal adaptations, though they can be a source of persistent discomfort for some people.
The muscles of the abdomen — particularly the rectus abdominis — undergo significant stretching as the uterus expands. The connective tissue that runs down the midline of the abdomen, the linea alba, also widens during this process. As a result, the deep stabilising muscles of the trunk work differently in pregnancy, and the demands placed on the rest of the musculoskeletal system shift considerably. This is one of the reasons why a sense of instability or heaviness through the pelvis and lower back is so common in the second and third trimesters.
The pelvis and sacrum sit at the centre of pregnancy's physical demands. As the uterus grows, it is supported and suspended by a network of ligaments that connect to the sacrum, the pelvic walls, and the abdominal wall. Understanding this ligament system is key to understanding why pelvic balance matters so much during pregnancy.
The round ligaments run from either side of the uterus, through the inguinal canal, toward the groin. As the uterus grows and its position changes, these ligaments stretch, lengthen, and bear new patterns of tension. Round ligament discomfort is one of the most common experiences in pregnancy — typically felt as a sharp, pulling, or aching sensation in the lower abdomen or groin, often triggered by sudden movement, rolling over in bed, or changing position quickly. It is a normal part of how the body accommodates its changing shape, though it can become a persistent and limiting discomfort for some.
The uterosacral ligaments connect the uterus to the sacrum at the back of the pelvis. When the sacrum is not moving or aligned symmetrically within the pelvis, the tension through these ligaments may be altered. This is one of the reasons why the position and movement of the sacrum is considered so central to pregnancy comfort — the sacrum is not just a spinal structure; it is directly connected to the ligament system that supports the uterus.
The broad ligament drapes laterally from the uterus to the pelvic walls on each side, forming a broad supportive curtain. Together with the round and uterosacral ligaments, it creates a sling-like support structure for the growing uterus. When the pelvis is well-balanced and the sacrum is moving symmetrically, these ligaments work in coordination. When there is structural asymmetry — whether from previous injury, habitual posture, or the physical demands of pregnancy itself — the tension through this ligament network may become uneven.
The following are all recognised musculoskeletal experiences that may arise during a normal pregnancy. They are not complications, but they can have a significant impact on daily comfort and quality of life:
None of these experiences are unusual. All of them reflect the scale of the physical adaptation the body is undertaking.
How Chiropractic Care May Support the Body During Pregnancy
Chiropractic care is not about treating pregnancy. It is about supporting the musculoskeletal system as it adapts to pregnancy's demands — helping the body remain mobile, well-coordinated, and as comfortable as possible through a period of continuous change.
The focus of care is the joints and soft tissues: ensuring the spine, pelvis, and sacrum are moving as well as possible; addressing areas where movement may have become restricted or uneven; and supporting the body in maintaining the kind of suppleness and balance that allows it to adapt most effectively to what is being asked of it.
The Webster Technique is a specific chiropractic analysis and adjustment protocol developed for use throughout pregnancy. It is certified through the International Chiropractic Paediatric Association (ICPA), and is one of the most widely recognised postgraduate training pathways for pregnancy chiropractic care.
The ICPA defines the goal of the Webster Technique as reducing the effects of sacral subluxation and sacroiliac joint dysfunction, in order to support neurobiomechanical function in the sacral and pelvic region. In practical terms, this means:
The technique is gentle and low-force — appropriate throughout pregnancy — and is designed to work with the body's own capacity for adaptation, not to override it. Webster Technique certification through the ICPA requires formal postgraduate training and examination in the technique and its clinical application in pregnancy.
At Body in Mind Chiropractic, Webster Technique care forms part of a broader approach to pregnancy support: one that begins with a thorough assessment, is guided by honest and transparent communication, and respects the central role of the pregnant person and their lead maternity carer in all decisions about their care.
If you have been exploring Spinning Babies which a widely used approach to supporting pelvic balance and movement during pregnancy, you may notice that many of its underlying principles overlap with those that inform pregnancy chiropractic care. Both approaches share a deep respect for the body's natural capacity and a focus on supporting the structural and mechanical conditions in which that capacity can function well. They approach this from different angles and are, for many people, a complementary combination.
Chiropractic care during pregnancy is a complement to, not a replacement for, the care provided by your midwife or lead maternity carer (LMC). Your midwife holds the primary role in supporting and monitoring your pregnancy and birth — and that role is irreplaceable. Pregnancy chiropractic care focuses specifically on the musculoskeletal dimensions of your experience: how your body is moving, where it may be holding tension or restriction, and how it can be best supported in continuing to adapt.
We would always encourage you to keep your midwife informed of any additional care you are receiving during pregnancy, and we are happy to communicate with your LMC directly where that is helpful.
Pregnancy is not a problem to be solved. It is one of the most physically demanding, biologically intricate, and extraordinary things the human body does. Chiropractic care during pregnancy is about supporting that — helping the body remain mobile and supple, and helping you feel as well-supported as possible throughout the journey.
If you would like to explore whether pregnancy chiropractic care might be a useful part of your support, we would be happy to have a conversation. Body in Mind Chiropractic is based in Beachlands and Howick and welcomes families from across the wider East Auckland community.
Every child deserves the opportunity to develop optimally. If you're curious about how spinal care might benefit your child's development, we're here to provide evidence-informed answers and gentle, age-appropriate care.