Intra-Uterine Constraint and Chiropractic
Pregnancy is a time of many changes, mentally, emotionally and physically. One area that chiropractors are often called on to help with is pelvic dysfunction during pregnancy. The sub-optimal alignment and function of the pelvis causes many implications for both the mother and the growing baby. This can lead to a common phenomenon called intra-uterine constraint.
What it is intra-uterine constraint?
Intra-uterine constraint is present when irregular forces outside the foetus obstructs the normal movement of the developing foetus (Pistolese, 2002). This means the baby does not have the optimal space to freely move inside the uterus and can lead to positional issues and other undesired outcomes (Prenatal Yoga Center, 2019).
What intra-uterine constraint means for the mother and the baby?
One of the most unwanted outcomes of intra-uterine constraint is delivery by caesarean section. The external forces on the growing baby due to imbalances in the pelvis can prevent the baby from settling into a head-down vertex position and lead to a vaginal breech birth or requiring a caesarean section; or a suboptimal alignment of the baby to the pelvic inlet and outlet leading to obstructed labour (Pistolese, 2002).
It has been observed that few breech babies will spontaneously turn to a head-down position after 34 weeks. The average rate of reported spontaneous version is approximately 9%. The number of caesarean sections performed due to breech presentation and dystocia has increased in recent years. The correlation between breech presentation and intra-uterine constraint makes pelvic dysfunction in pregnancy an important issue to address (Pistolese, 2002).
Research has also shown structural effects on both the mother and the growing baby. Several structural defects of the peripheral and craniofacial skeleton has been observed in new-borns exposed to intra-uterine constraint. Forces of intrauterine constraint also negatively affect the mother’s spine during the antenatal and perinatal periods (Pistolese, 2002).
How and why does intra-uterine constraint happen?
During pregnancy and labour, the pelvic ligaments relax to allow a spreading of pelvic bones. Throughout this period, the sacrum has a multidirectional movement for 1 to 3 mm (Pistolese, 2002). This expanded movement increases the potential of the pelvis to misalign. Misalignment and imbalances significantly alter the shape of the pelvic inlet and outlets as demonstrated by the images below. The change to the shape of the pelvis affects the position and alignment of the growing baby as well as the size of the birth canal (Pistolese, 2002).
Figure 1. A well-aligned pelvis, left; subluxated pelvis, middle and right (Pistolese, 2002).
Furthermore, alignment of the mother’s sacrum is important for the head rotation of the baby. If the sacrum is no longer aligned with the pelvic bones, the baby’s head can be held in place and be unable to rotate. This can lead to the head being tipped to one side or the baby being stuck in the posterior position (Prenatal Yoga Center, 2019).
As well as the bony structures, the many ligaments that suspends the uterus in the abdominal cavity also play a part in intra-uterine constraint. The uterus can be imagined as a big hot air balloon supported by 8 pelvic ligaments. Tightness or twisting of any of the ligaments means that the muscle of the uterus is pulled upon and is no longer big, round and symmetrical. This can affect the baby’s ability to move freely (Prenatal Yoga Center, 2019) as well as cause compression or twisting of the baby’s neck and spine (Crystasl Chiropractic, n.d.).
Figure 2. Anatomic drawing showing a superoanterior view of the female pelvis and the suspensory ligaments of the uterus. (Kaniewska et al., 2018).
Figure 3 Drawing showing a lateral view of a pregnant uterus with its suspensory ligaments (Iskra, 2020).
Lastly, the psoas muscle, or the hip flexor, plays a large role in stabilising and aligning the pelvis. With prolonged sitting, postural imbalances, cycling, and running, the psoas muscles can become chronically tight and spasmodic. Overly tight psoas muscles may lead to misalignment of the pelvis, and in turn obstruct the baby from normal movements and affect optimal foetal positioning (Prenatal Yoga Center, 2019).
What can be done about intra-uterine constraint?
One of the most common ways to correcting intra-uterine constraint is using a chiropractic method called the Wester Technique. The focus of the method is in relieving the imbalance in the ligaments and the pelvis, in order to allow the body to restore proper biomechanics. This in turn facilitates the baby to move into optimal alignment. It has demonstrated a high rate of success (82%) in relieving the musculoskeletal causes of intrauterine constraint and is successful in supporting babies to turn from breech presentations to head-down presentations (Pistolese, 2002).
The conventional obstetric method of turning breech babies is External Cephalic Version (ECV). ECV is a manoeuvre with which the practitioner seeks to manually turn the baby using force. Even though ECV is considered non-invasive and is much lower risk than caesarean sections, it has been associated with abruption of the placenta and other complications. Compared to the Webster Technique, it is risky, and the success rate is only 58% (Crystasl Chiropractic, n.d.).
Stretching and yoga are also supportive for balancing the musculoskeletal structures during pregnancy. By encouraging proper alignment of the pelvis, these practices can help the baby to have more freedom of movement, as well as other body-mind balancing benefits (Prenatal Yoga Center, 2019).
Another valuable resource for pelvic balance and relieving intra-uterine constraint is a method called Spinning Baby (2021). There are many free videos and information on their website that can be practised at home, including a weekly practice that can be done with a partner. This is a method that I have personally used with many women who’s babies had occipital posterior or breech presentations. Almost all of these women saw remarkable results and went on to have natural vaginal births.
Changes to the pelvis is a natural part of pregnancy and labour. With the regular chiropractic care and an appropriate self-care plan, pelvic alignment can be optimised, leading to a smoother transition of your baby from the womb. At Mt Eden Chiropractic, our chiropractors are trained in the Webster Technique. Please feel free to reach out to us with any questions about your or a loved one’s pregnancy.