Trigonometric characteristics of episiotomy & pregnancy variables

Episiotomy, though simple and most common surgical procedure performed in labour theatre, has a lot of bearing on patients' recovery postpartum. The episiotomy angle and length can influence probability of anal sphincter trauma, ease of delivery and post-delivery recovery in variable ways. We hypothesize that a universal measure of angle (60°) and length might not be ideal for all women. This aim of this cohort study was to establish association of episiotomy trigonometric characteristics (length and angle) with antepartum, intrapartum and postpartum factors.

A total of 504 pregnant women who delivered with an episiotomy after 34 weeks of gestation were included. Antenatal, intrapartum, and postpartum variables were collated. These women were examined for episiotomy length, angle, signs of infection/inflammation and pain using Visual Analogue Scale (VAS). All of them were followed up till they were discharged frm the hospital.

A smaller episiotomy angle (<15°) was associated with significantly higher VAS score as compared to angle 35°-40°. We observed that as birth weight increases, mean episiotomy length and angle progressively increases. Longer head circumference was associated with longer length of episiotomies (p < 0.01). Instrumental deliveries were associated with higher length and angle of episiotomy.

We observed a relationship of trigonometric characteristics of episiotomy with variables like birth weight and HC. We feel the angle and length of episiotomy cannot be defined as a universal constant. It depends of maternal and fetal variables. We propose that episiotomy should be tailored for every patient to achieve the most optimal result for her.

This study reflects episiotomy practice at a tertiary care hospital. We must conduct larger studies to evaluate variables that influence the trigonometric characteristics of episiotomy.