- To estimate the true conjugate (the smallest inlet measurement of the pelvis), deduct 1.5 cm from the diagonal conjugate (usually 12 cm). A true conjugate of 10.5 cm enables the fetal head (usually 10 cm) to pass.
- The smallest outlet measurement of the pelvis is the intertuberous diameter, which is the transverse diameter between the ischial tuberosities.
- The smallest outlet measurement of the pelvis is the intertuberous diameter, which is the transverse diameter between the ischial tuberosities.