In this study, we had 406 participants who 208 were in the CS group and 198 in the NVD group.
AFTER BIRTH LBP:
Generally and without considering the delivery method, 40.4% of participants reported LBP that this number fell to 36.9% (table 1). This finding confirms the result of past studies which stated some pregnancy-related injuries heal by time. like Woolhouse etl. Study in 2012 which was done on 1502 participants with 3, 6 and 12 months postpartum follow-ups for detecting LBP persistence and they found out that most reported pain was healed by time.[19]
There are so many factors for post-delivery LBP. For example Breen and etl. In a study on 1402 women in 24-48 hours after delivery with 1-2 months follow up, reckoned that sever PLBP, early onset of pain in pregnancy, excessive weight gain during pregnancy and late weight loss after delivery are effective for chronicity of LBP after birth.[20] In nutshell, after birth pain is expected to recover by the time even without any medical intervention.
Also, we found a descending trend in each delivery method reported LBP by the time, for CS from 38.9% to 35.6%(table 2) and in the NVD group from 41.9% to 38.4%(table 3).
In this study, we didn’t find any relation between the delivery type and postpartum LBP.
PAIN RELATED FUNCTIONAL DISABILITY:
As mentioned before, the pain reporting rate decreased by time, but this doesn’t mean that functional disability index scores, fell as well.
In a group study for the CS, the method illustrated that despite a declining rate of reported pain, an increase in TSK and OSW scores were seen. duing cesarean procedure, some vital supportive tissue like abdominal superficial and deep fascia is cut and abdominal wall muscles functional ability are affected, some disturbance in spinal column stability is expected. The result of supportive tissue alteration is some difficulties in a transitional position. moreover, experienced pain in some casual positions may stop new mom from some movement.
In the NVD group, no significant relation was found in 2 stages, which means despite pain decrease, no change in disability index score were found.
To sum up, we get into this conclusion that pain reduction is not necessarily associated with disability index scores decrease.
COMPARING DISABILITY BETWEEN 2 DELIVERY METHODS:
In our study, we detect a significant relationship between the two delivery methods.
In the first stage, disability index scores, in a way that NVD group owned a higher score.(OSW p-value=0.02, RM p-value=0.03)(table 11) and also NVD group, pain reporting was higher than the CS group.(NVD=41.9%, CS = 38.9%). So we can get to this conclusion that in the first stage, the NVD group not only has a higher rate of pain but also a higher disability score.
To highlight the possible reasons of this difference lies in both methods procedure:
During the NVD method, major force is on pelvic girdle, lower back and vaginal pathways that can lead to on some sacral and pelvic neurons, pubic symphysis diastasis and unspecific low back pain. High imposed stress on pelvic girdle and surroundings can cause illiosacral joint instability. Post NVD ct scans indicate abnormal pubic symphysis opening and gas accumulation. [21] Long labor time may lead to priformis muscle contusion.[22-23] moreover, sometimes episiotomy incision leads to some adhesion that can affect pelvic floor muscle sufficiency and as we know, pelvic girdle muscles are important in lumbar stability, so their insufficiency can cause to functional instability.
CS is counted as a major abdominal surgery. incision is inserted on the upper pubic area. Central abdominal wall muscle insertion is on the pubic bone area, so these muscles play an important role in the dynamic stability of low back and pelvic girdle. C section incision can affect the biomechanics of back and pelvis by possible inhibition of rectus abdominis muscle in reaction to surgical procedure. [24] during CS superficial and deep fascia are cut and this may present some myofascial adhesion which is the main reason for myofascial pattern complications.adhesion in fascial pattern may cause LBP, unilateral or bilateral hip pain and lower cross syndromes.
As mentioned above, both delivery methods have considerable effects on stabilizing factors of body core. Due to major effects of CS on the abdominal wall, we expected more pain and disability in this group, especially immediately postpartum, but the study results showed that the effect of pressures during NVD procedure, make new moms more suffering from pain.
In some studies, the imposed pressures on pelvic and low back during the NVD process are supposed as major predisposing factors for future chronic SI joint, pubic symphysis and sacrococxygeous pain.[25-26]
As we know every surgery underlie chronic pain. A study result reported 4-10% of chronic pain in the CS group, especially if they had experienced prior CS.[24] This phenomenon may result in post-operation scar adhesion and movement patterns disturbance.