2.) Obstetrical Pelvimetry And Measurements Flashcards
What is obstetrical pelvimetry ?
Obstetrical pelvimetry is conducted to evaluate the size and shape of a pregnant woman’s pelvis. This helps us understand whether the pelvis can allow the baby to pass through during a vagina delivery.
Name the two ways that an obstetrical pelvimetry can be conducted in ?
1.) Manual examination
2.) Radiological methods
Name the 4 pelvic shapes ?
1.) Gynaecoid the most favourable shape for vaginal delivery it is round and wide.
2.) Android , Heart shaped and narrow less favourable for vaginal delivery.
3.) Anthrapoid , oval shaped with a long anteroposterior diameter , vaginal delivery is possible.
4.) Platypelloid , Flat and wide with a short anteroposterior diameter, difficult for vaginal delivery.
What are the dimensions of the AP pelvis of the True conjugate ?
11 cm this is the distance from the top of the pubis symphysis to the middle of the sacral Promontary.
It is not measured directly in patients due to the bladders position but can be estimated by subtracting 1-2 cm from the diagonal conjugate.
What are the dimensions of the Diagonal conjugate?
13 cm measured from the lower pubic symphysis to the middle sacral promontory
What are the dimensions of the obstetrical conjugate ?
10.5cm to 11cm , the smallest distance the baby’s head must pass through during delivery
What is the Classification of the True Conjugates Based on Degree of Contraction ?
1.) True conjugate is less than 11 cm but not less than 9 cm vaginal delivery possible.
2.) True conjugate 9 to 7.5 cm complications may arise but delivery still possible.
3.) True conjugate 7.5 to 6 cm C-section is required.
4.) True conjugate less than 6 cm delivery impossible without C-section.
Name the 3 pelvic planes?
Inlet ( Entrance to the pelvis )
Midpelvis ( Widening and tightening )
Outlet ( Exit )
What does the pelvic inlet consist of ? And what are the dimensions of it including AP , transverse and oblique ?
The pelvic inlet includes the linear terminalis the iliopectineal line and the sacral promontory.
- AP 11cm
- Transcerse 12cm
- Oblique 13cm
What does the midpelvis consist of ?
The plane of widening : AP diameter 12cm and transverse is 12cm
( widest part)
The plane of tightening : AP diameter 11cm , the distance between the ischial spines is 10.5cm
(Narrowest part)
What does the pelvic outlet consist of ?
1.) Tuberositas Ischi
2.) Lower symphysis pubis
3.) Tip of the coccyx
How can you measure distancia cristarum ?
How can we measure distancia spinarum ?
How can we measure distancia trochanterica ?
How to measure the external conjugate ?
