Pelvic girdle: adaptation for childbirth & clinical Flashcards
what do the majority of women have? (type of pelvis)
The majority of women have a gynaecoid pelvis
which type of pelvis do male have?
android pelvis
what is main difference between gynaecoid pelvis (F) and android pelvis (male)?
The slight differences in their structures creates a greater pelvic outlet, adapted to aid the process of childbirth
structure of gynaecoid pelvis?
A wider and broader structure, lighter in weight
shape of pelvic inlet of gynaecoid pelvis?
oval-shaped
shape of pelvic inlet of android pelvis?
heart-shaped
significance of ischial spine in gynaecoid pelvis?
Less prominent ischial spines, allowing for a greater bispinous diameter
sub-pubic arch in gynaecoid pelvis?
A greater angled sub-pubic arch, more than 80-90 degrees
significance of sacrum in gynaecoid pelvis (compared to android pelvis)?
A sacrum which is shorter, more curved and with a less pronounced sacral promontory
other features of gynaecoid pelvis adapted for childbirth aside from bony adaptations?
the sacrotuberous and sacrospinous ligaments can stretch under the influence of progesterone and increase the size of the pelvic outlet further
what does the foetus pass through during childbirth?
The lesser pelvis is the bony canal through which the foetus has to pass during childbirth
what requires to be measured to determine the childbearing capacity of the mother
determine the diameter of the lesser pelvis (bony canal) - the childbearing capacity of the mother
how can the diameter of the lesser pelvis (bony canal) be determined?
The diameter can be determined by a pelvic examination or radiographically
which 2 measurements are of significance when determining the diameter of the lesser pelvis (bony canal)?
Obstetric Conjugate
Diagonal Conjugate
what is significant about obstetric conjugate in childbirth?
used to determine the narrowest fixed distance that the foetus would have to negotiate
how do you measure for the obstetric conjugate?
the minimum antero-posterior diameter of the pelvic inlet is measured
which distance is the obstetric conjugate?
This distance is between the sacral promontory and the midpoint of the pubic symphysis (where the pubic bone is thickest) and is known as the obstetric conjugate (or true conjugate)
can the obstetric conjugate be measured? why?
However, this measurement cannot be taken clinically, due to the presence of the bladder
what is the diagonal conjugate?
the alternative, measuring from the inferior border of the pubic symphysis to the sacral promontory
how can the diagonal conjugate be measured?
can be measured manually via the vagina
how do you measure the diagonal conjugate?
To do this you use the tip of your middle finger to measure the sacral promontory and then using the other hand to mark the level of the inferior margin of the pubic symphysis on the examining hand. You then use the distance between the index finger and the pubic symphysis to measure the obstetric conjugate
what is the ideal measurement of the diagonal conjugate?
ideally 11cm or greater
in addition to measuring the diagonal conjugate, what is carried out?
a mid-pelvis check is carried out
how do you carry out a mid-pelvis check?
the clinician is testing for straight side walls and measuring the bispinous diameter
what is the narrowest part of the pelvic canal?
mid-pelvis check:
bispinous diameter
how can the width of the subpubic angle at the pelvic outlet be determined?
by the distance between the ischial tuberosities
