What is the diameter of fetal skull?
The greatest circumference of the head, which corresponds to the plane of the occipitofrontal diameter, averages 34.5 cm (13.6 in), a size too large to fit through the pelvis without flexion. The smallest circumference, corresponding to the plane of the suboccipitobregmatic diameter, is 32 cm (13 in).
How is female pelvis adapted for childbirth?
Compared to the male, the female pelvis is wider to accommodate childbirth. Thus, the female pelvis has greater distances between the anterior superior iliac spines and between the ischial tuberosities. The greater width of the female pelvis results in a larger subpubic angle.
What are the diameters of female pelvis?
Diameters
| Name | Description | Average measurement in female |
|---|---|---|
| Anatomical conjugate | Extends from the pubic symphysis to the promontory; | about 120 mm. |
| Diagonal conjugate | Extends from lower margin of the pubic symphysis to the sacral promontory; | about 130 mm. |
What are the major differences between the male pelvis and female pelvis that permit childbirth in females?
The general structure of the female pelvis is thinner and less dense, in comparison to the thick and heavy male pelvis, which is designed to support a heavier body build. The true pelvis is wide and shallow in the female, and the pelvic inlet, also known as the superior pelvic aperture is wide, oval and rounded.
What is the smallest diameter of fetal skull?
During vertex presentation, the fetal head flexes, bringing the chin to the chest, forming the smallest possible fetal head diameter, measuring approximately 9.5cm.
Which of the following is highest diameter of the female pelvis?
between the farthest two points on the iliopectineal lines. It lies 4 cm anterior to the promontory and 7 cm behind the symphysis. It is the largest diameter in the pelvis.
What are two characteristics of the female pelvis?
The female pelvis is usually more delicate than, wider than, and not as high as the male pelvis. The angle of the female pubic arch is wide and round. The female sacrum is wider than the male’s, and the iliac bone is flatter. The pelvic basin of the female is more spacious and less funnel-shaped than the male’s.
What is the highest diameter of female pelvis?
Platypelloid pelvis (5%): It is a flat female type. All anteroposterior diameters are short….
- between the farthest two points on the iliopectineal lines.
- It lies 4 cm anterior to the promontory and 7 cm behind the symphysis.
- It is the largest diameter in the pelvis.
What is pelvis diameter?
Diameters of the Pelvic Inlet The anatomical conjugate or true: Measured between the sacral promontory and the upper edge of the pubic symphysis and measures an average of 11.0 cm.
Why is the pelvis of a female wider than the pelvis of a male?
Because the female pelvis is adapted for childbirth, it is wider than the male pelvis, as evidenced by the distance between the anterior superior iliac spines (see (Figure)). The ischial tuberosities of females are also farther apart, which increases the size of the pelvic outlet.