Effect of Pregnancy on Peripheral Nerve System

It has been proposed that normal pregnancy increases the risk of carpal tunnel syndrome (CTS) and also could be a risk factor for polyneuropathy. We performed this study to evaluate the effect of pregnancy on peripheral nervous system. During one year, 30 healthy pregnant women were examined initially at the first or second month of their gestation and then at their 3rd trimester. Sensory physical examination of limbs including touch, pain and deep sensations was performed and also presence of paresthesia was asked. Sensory and motor conduction studies with f wave study of Median, Ulnar, Sural and Tibial nerves were performed in all of them. Those with abnormality in first study were excluded from further investigation. Non of our study group had any sensory complaint in their upper or lower limbs in the first and second visits. The only statistically significant finding was increased latencies of median nerve SNAP when stimulation was performed in distance of 14 cm of recording electrode in right and left sides (P= 0.008)(P = 0.003) but these parameters also remained in normal range. Clinical and electrodiagnostic findings in our study showed that there was no increased incidence of CTS and polyneuropathy among pregnant women.