Maternal Structure

Question 1

What four bones make up the female pelvis?

Answer 1

Sacrum, coccyx, and the 2 innominate bones

Question 2

What are the joints of the pelvis?

Answer 2

Symphysis pubis, sacrococcygeal, sacroiliac joints (2)

Question 3

What is significant about ischial spines?

Answer 3

• The ischial spines afford important evidence of the size of the pelvic outlet
• Spines of the ischium project medially into the pelvic cavity
• The imaginary line drawn from one ischial spine is used to assess how far the baby’s head has descended into the pelvis when examining vaginally

Question 4

What is the smallest diameter of the maternal pelvic outlet?

Answer 4

The transverse diameter