The doctor of chiropractic plays an essential role in both the mother and baby’s musculoskeletal and nerve system throughout pregnancy and in preparation for birth. Weight gain, compensating postural changes and hormonally induced ligament laxity add to the woman’s propensity towards pelvic misalignment in pregnancy leading to an elevation in low back pain affecting quality of life and labor outcome. These misalignments also affect neurological function of the uterus affecting pregnancy and birth outcome. Additionally, the loss of biomechanical integrity of the mother’s pelvic muscles and ligaments and their resulting uterine support may adversely cause a condition known as intrauterine constraint affecting infant positioning in pregnancy and birth.
Varney’s Midwifery text states, “The potential for damage in pregnancy and the postpartum period to a woman’s neuro-musculo-skeletal structure is great. Shifts in the center of gravity forward and slightly up destabilize her posture and realign the carriage of weights and forces through her joints, predisposing nerves, muscles, bones, and connective tissues to damage. Increased levels of relaxin and elastin further aggravate this situation.” (1) Gait compensations and increased biomechanical loads lead to further strain on spinal segments and their supporting structures.
Female sacroiliac joints tend to be flatter, with a wider retroarticular space and longer interosseous ligaments, all promoting greater mobility.(2) As hormonal changes affect supporting musculature and ligament laxity, there is an increase in spinal and sacroilloiac articulations compensation and mobility. If a motion segment is compensating for a lack of mobility at an adjacent level, then these segments may become more hypermobile. (3)(4).
“Maternal weight gain is most significant during this gestational period. This contributes largely to the profound biomechanical compromise of the lumbosacral spine. With a drastic shift in the gravitational weight bearing of the mother, pelvic musculoskeletal function, principally of the sacroiliac and hip joints is imperiled. This leads to often significant soft tissue structure changes such as hypertonicities or ligament laxity, which in turn creates biomechanical instability. Not just the lumbosacral spine but compensatorily, the thoracic and even cervical spines acquire a diversity of combinations of aberrant segmental and global motion. The unfortunate typical short radius sacral curve of later pregnancy provides the foundational imbalance for thoracic hyperkyphosis and cervical kypholordosis. Cellular edema and inflammation, along with anatomical yielding of the intervetebral foraminae, generate neurophysiology of the important spinal nerve tissues with resultant cellular and aggregate tissue malfunction. Pelvic misalignment is physiologically inherent to the last three months of pregnancy.(5)
Varney’s midwifery states, “In the antepartal period, changes in posture occur gradually and can be responsible for a great many discomforts over the course of the pregnancy.” (6) The prevalence of low back pain during pregnancy can be as low as 42.5% (7) and as high as 90% (8) One study revealed that 28% of women experience back pain by the twelfth week of gestation.(9) Because of the biomechanical compensations discussed above, it is not unusual for pregnant women to experience pain in multiple areas of her spine including sacral, lumbar, thoracic, cervical and cranial.
Low Back Pain
Back pain in pregnancy is a frequent clinical problem. Out of 200 women, seventy-six percent reported back pain at some time during pregnancy. Sixty-one percent reported onset during the present pregnancy. 30% with the highest pain score reported great difficulties with normal activities. 10
Another study showed One survey reports the prevalence of LBP in pregnant women to be about 50% . It further states that the most common reason for severe low back pain in pregnancy was dysfunction of the sacroiliac joints. 11
It is important to note that the prevalence of back pain in pregnancy, the need to address these concerns without the harmful effects of drugs and the significance of this pain on the woman’s quality of life and function are all significant reasons to establish safe and reliable models of care as provided by chiropractic adjustments for this population. 12,13,14,15
Currently, most published research on chiropractic care in pregnancy addresses the efficacy of the adjustment for the resolution of low back pain. One study revealed that 75% of women who received chiropractic adjustments during their pregnancy stated that they experienced relief of their pain and discomfort. 16 Two other studies address the incidence of increased LBP in pregnancy and the positive results of spinal and pelvic adjustments. 17,18. Another study concludes that intensive spinal adjustments are not only effective for the initial intensive care of low back pain, the authors also suggest that maintenance spinal adjustments after initial intensive care may be beneficial to patients to maintain subjective post intensive disability levels. 19
Another study looked at back pain in both pregnancy and delivery and found a statistically significant association of back pain between the two events. The group of women who received chiropractic adjustments also experienced less pain during labor. 20
This study not only recommended adjustments for low back pain in pregnancy, it recommended on-going maintenance care beyond the initial symptomatic, initial intensive care. Based on the results, the researchers concluded: "This study appears to confirm previous reports showing that LBP and disability scores are reduced after spinal manipulation. It also shows the positive effects of preventive chiropractic treatment in maintaining functional capacities and reducing the number and intensity of pain episodes after an acute phase of treatment. 21
Intrauterine Constraint and Female Biomechanics
Misalignment of the sacrum in the pregnant pelvis may be a major contributing factor to intrauterine constraint. Intrauterine constraint is defined as any forces external to the developing fetus that obstructs the normal movement of the fetus.
The link between a biomechanical dysfunction and an in utero constraint situation is the ligamentous attachments of the uterus to the bony maternal pelvis. The sacral torsion thought to be transmitted by ligaments to the uterus, creating an uneven muscular tension in the uterine walls. This muscular dysbalance constricts fetal motion so it does not have the freedom any more to turn into the vertex position. Anatomically the uterus is suspended by 3 major ligaments a) the broad ligaments b) the uterosacral ligaments and c) the round ligaments
The broad ligaments are double layers of peritoneum extending from either sides of the uterus to the lateral walls and floor of the pelvis. The base of the broad ligament, which is quite thick, is continuous with the connective tissue of the pelvic floor. These ligaments are the most important ones for the proper position of the uterus and preventing uterine prolaps.
The round ligaments extend from lateral, superior portion of the uterus towards the labia major, inserting with the inguinal ligament within a fold of the peritoneum continuous with the broad ligament. They are comprised of smooth muscle cells continuous directly with those of the uterine wall and a certain amount of connective tissue. They prevent the uterus from moving posterior, keeping it in a normal anterior position. It is proposed by this author, that unilateral tension in the round ligament as caused by a torqued uterus from sacral dysfunction increases uterine tension and imbalance. 25
Forrester and Anrig say, “Specifically, sacral rotation causes an anterior torquing mechanism on the uterine ligaments and musculature, decreasing space and altering the environment for the fetus… When correction of the sacral subluxation occurs, the structure and therefore the function of the uterine structures are improved allowing the fetus to position itself properly.” 23
Intrauterine constraint contributes to abnormal fetal positioning in pregnancy and labor. Fetal presentations other than cephalic or positions other than anterior may result in frequent birth complications for the mother and baby.
Intrauterine constraint in pregnancy may cause irregular spinal development of the fetus as well. Compromised spinal development of the baby may have permanent adverse effects on the baby’s nerve system. Forrester and Anrig write: “The critical effects of in-utero constraint involve the biomechanical considerations on fetal development., the potential for a reduced efficiency in labor resulting in a longer harder labor process with an increased incidence of anoxia, brain damage, asphyxia, prolapse of the umbilical cord and intrauterine death and a greatly elevated propensity toward operative delivery which exacerbates the danger of trauma to the neonate.” 24
Therefore chiropractic care in pregnancy increases quality of life for the mother and also has significant implications on the future health and well-being of the infant.
Many specific chiropractic analysis and techniques have adapted protocols to suit the pregnant patient. Some post graduate college courses specific to perinatal chiropractic include: Gonstead, Thompson, Logan, SOT, Activator, Diversified.
One specific chiropractic analysis and diversified adjustment, the Webster technique was developed particularly for the pregnant patient. The Webster technique has been utilized to correct the muscular skeletal causes of intrauterine constraint. 25,26,27,28,29,30,31,32 resulting in better fetal presentation and positioning at birth. The Webster technique is defined as “a specific chiropractic analysis and adjustment that reduces interference to the nerve system, facilitates balance in the pelvic muscles and ligaments, which in turn reduces torsion in the woman’s uterus, alleviating intrauterine constraint, and optimizing fetal positioning.” 35
There are several text books and reference manuals in chiropractic which each address the importance of chiropractic care in pregnancy. 37,38,39,40. Each text includes some or all of reasons for chiropractic care throughout pregnancy discussed above.
There are no known contraindications to chiropractic spinal and pelvic adjustments throughout pregnancy.
Chiropractic adjustments characterized as high-velocity, low amplitude thrusts are frequently applied to sites of vertebral subluxations in the pregnant patient. To date, no reported adverse events have been associated with this type of care.
The International Chiropractic Pediatric Association has conducted two Practiced Based Research Surveys relevant to pregnancy. Both studies received IRB approval from Life University.
Preliminary results of the ICPA’s first PBRN: Chiropractic Care and the Webster Technique collected data from 274 cases. No adverse effects were reported. 13 aggravations (slight soreness post first adjustment with 100% resolution) were noted by the doctors. The results of these preliminary findings PBRN have been presented at several conferences and have been submitted for publication. 41
The ICPA’s second PBRN: Chiropractic Care in Pregnancy is still in progress. At the time of this writing, there were over 100 cases submitted. To date, no adverse affects were reported by either the doctor or patient. Only two aggravations (slight soreness post first adjustment with 100% resolution ) were reported by the doctors. In 48 of the cases submitted, the doctor used the Webster technique. The remaining adjusting techniques used were those described above in the Technique section of this paper.
Defining Dystocia and Its Prevention with Prenatal Chiropractic
In addition to continuously staying abreast of academic knowledge and clinical adjustive skills pertinent to care in pregnancy, it is important that the doctor of chiropractic understand the biomechanics of the pregnant female pelvis and its relationship to the neuro muscular causes of dystocia. Dystocia is abnormal function in labor and is the number one cause for invasive intervention in birth that leads to trauma and subluxation in the mother and infant.
In Williams Obstetrics Textbook, the authors define dystocia as “Abnormal Labor.” They further emphasize, “Dystocia is very complex, and although its definition- abnormal progress in labor seems simple, there is no consensus as to what ‘abnormal progress’ means. Thus, it seems prudent to attempt a better understanding of normal labor in order to determine departures from normal.” 42
Williams Obstetrics list the causes of dystocia to be:
When examined from a neuro-muscular perspective, each of these causes of dystocia may potentially be prevented with specific chiropractic adjustments of the pregnant woman’s spine and pelvis throughout pregnancy in preparation for birth. In other words, each cause of dystocia is addressed with specific, regular chiropractic care throughout pregnancy.
Correlating the causes of dystocia with the corrective accomplishments of the chiropractic adjustment is as follows:
Understanding these neuro muscular contributors of dystocia provide the doctor of chiropractic with even greater technical expertise, higher patient compliance and an increase of inter-professional referrals with birth care providers.
Chiropractic Care for Better Birth Outcome
There have been several studies emphasizing the significance of spinal and cranial adjustments as performed by trained doctors for the prevention or elimination of dystocia 47, 48, 49, 50, 51
Additional benefits relevant to birth outcome have included:
C-section are determined mainly by the failure of labor to progress (dystocia). In the US, over one fourth of all children born annually are delivered by c-section. 51 The World Health Organization recommends that the c-section rate should be about 10-15% . 52.With this increased c-section rate comes its questionable validity and the accompanying adverse effects to both the mother and infant. 53
Therefore, the prevention of dystocia by nautral non-invasive methods and its service in public health is reason enough for further research into the association of chiropractic care for better birth outcome.
A look at the birth process and its effects on the infant’s spine and nerve system. 54,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72
There is much to be done in the clinically based research arena to continue to substantiate the efficacy of chiropractic care in pregnancy. Beyond the presence of back pain or other overt symptoms, regular chiropractic adjustments during pregnancy offer promise in the reduction of the neuromuscular causes of dystocia. This increases the opportunity for the mother and baby to have a safer, easier more natural birth experience. All pregnant women should be routinely examined throughout pregnancy by a Doctor of Chiropractic for the presence of VSC. Facilitating a healthy pregnancy and restoring a normal physiological environment with the chiropractic adjustment for natural birth is well within the chiropractic scope of practice.