Pelvimetry

Question 1

What are term measurements of fetus?

Answer 1

BPD: 9.3cm
FL: 7.4cm
CRL: cm + 6.5cm = weeks gestation

Question 2

What is the definition of engagement?

Answer 2

BPD passed the plane of the inlet, the present part is at ischial spines.

Question 3

What is the obstetrical conjugate?

Answer 3

shortest AP diameter of the birth canal and it reflects the capacity of the pelvic inlet to allow the passage and the engagement of the fetal head.
Defined as: Measured from the sacral promontory to the point bulging the most on the back of the symphysis pubis, located about 1 cm below its upper border. It measures 10.5 cm on average; it is the lesser anteroposterior diameter.

Question 4

What are the 3 diameters of the pelvic inlet?

Answer 4

Anatomical conjugate (true)=11cm, obstetric conjugate=10.5cm, the diagonal conjugate=12.5cm

Question 5

What is the anatomical (true) conjugate?

Answer 5

Measured between the sacral promontory and the upper edge of the pubic symphysis and measures an average of 11.0 cm

Question 6

What is the diagonal conjugate?

Answer 6

Measured between the sacral promontory and the lower edge of the pubic symphysis, measuring an average of 12.5.