Vaginal birth may be natural but it can also be very damaging. It has long been known that C-section reduces the risk of subsequent urinary incontinence. Now a new study provides evidence that C-section also protects the nerves responsible for pelvic sensation.
The study is The impact of pregnancy and childbirth on pelvic sensation: a prospective cohort study just published in the prestigious journal Nature.
The authors note:
Pelvic organ prolapse, urinary, bowel and sexual dysfunction, collectively termed pelvic floor dysfunction (PFD) is estimated to affect one in three women in high and middle income countries with a significant public health cost…
This is the first study to report the effect of pregnancy and mode of delivery on sensory function of the pudendal nerve.
We hypothesised sensory nerves are unaffected by pregnancy and injured following vaginal birth. Our primary objective was to investigate the effect of mode of delivery on pelvic sensation…
What did they study?
One hundred and fifty nulliparous women were recruited from antenatal clinics between 10 and 40 weeks gestation…
Women were assessed in the third trimester (antenatal), at 3 and 6 months postnatal…
The primary outcome measure was proportional change in sensation following a normal vaginal delivery (NVD), assisted vaginal delivery (AVD) and caesarean section (CS).
Secondary outcome measures were baseline sensation in pregnancy compared to non-pregnant normative data and proportional change in sensation across the postnatal period.
Among other findings, the authors report:
At 3 months postnatal vaginal and clitoral vibration sensation in women delivered by CS showed greater recovery to antenatal levels than following a NVD or AVD. By 6 months postnatal sensation in the NVD group was comparable to the CS group, but the same recovery was not evident in the AVD group.
In other words, C-section protected pelvic nerves while vaginal birth damaged them. The greatest damage occurred after assisted vaginal birth with forceps.
Our results indicate that women who underwent CS did not experience any deterioration in pudendal nerve sensory function, suggesting CS is neuroprotective for sensory nerves. Women who had a NVD showed slow recovery at 3 months postnatal and demonstrated enough recovery to restore function to CS levels by 6 months postnatal, suggesting nerve damage in this group is transient. AVD was associated with the greatest reduction in sensory nerve function and less recovery of function by 6 months postnatal than a CS or NVD, suggesting AVD causes profound and potentially irreversible nerve damage.
The authors conclude that women should be counseled about the risk of vaginal delivery causing impairment of pelvic sensation and the neuro-protective effect of C-sections.
The bottom line is that maternal request C-sections make a great deal of sense for women anxious to avoid either incontinence, sexual dysfunction or both!
