Female Pelvis: True Pelvis and False Pelvis | Landmarks of Female Pelvis | Diameters of Female Pelvis

Female Pelvis: True Pelvis and False Pelvis

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There are 4 types of pelvis humans have.

1. Gynecoid
2. Android
3. Anthropoid
4. Platypelliod

Female pelvis are Gynecoid pelvis and the male pelvis are Android pelvis. A gynaecoid pelvis is a very good pelvis for females for childbearing and labor. The female pelvis plays a very vital role in pregnancy to give birth of a child.

Structure of Female Pelvis:

The female pelvis consists of 2 innominate bones, one sacrum and a coccyx. These innominate bones consist of a pair of ilium, a pair of ischium and a pair of the pubis.

Landmarks of Female Pelvis:

There are 9 landmarks present in the female pelvis which are listed below:

Female Pelvis

1. Sacral promontory
2. Ala of Sacrum
3. Sacroiliac joint
4. Iliopectineal line
5. Iliopubic eminence
6. Pectineal line
7. Pubic tubercle
8. Pubic Crest
9. Symphysis pubis

Landmark of Female Pelvis

Joints of Female Pelvis:

3 joints are present in the female pelvis.

• Sacroiliac Joint
• Sacrococcygeal Joint
• Symphysis Pubis

Classification of Female Pelvis:

The female pelvis is divided into two parts:

A. False Pelvis:

It is formed by the upper flared-out portion of the ilium. It protects the abdominal organs. It has no obstetrical importance.

B. True Pelvis:

The true pelvis is the bony canal through which the fetus passes during birth.

✩ The true pelvis has three parts:

Diameter of True Pelvis:

⇨ True pelvis has

• Inlet (Brim)
• Cavity
• Outlet

⇨ All the diameters of the inlet, cavity and outlet are described below:

INLET

It is formed by the sacral promontory, the iliac bones laterally and the pubic bones anteriorly Shape: Transversely oval or Heart shape

➥Diameter of Brim or Inlet:

➢Anteroposterior Diameter(11 cm)

It is the line from the sacral promontory to the upper border of the symphysis pubis. This diameter is of three types- ➩True Conjugate or Anatomical Conjugate It extends from the sacral promontory to the top of the symphysis pubis. ●Its normal measurement is 11 cm or more. ➩Obstetrical conjugate It is the distance between the midpoint of the sacral promontory to prominent bony projection in the midline of the symphysis pubis ●Its measures 10 cm ➩Diagonal Conjugate Distance between the lower border of the symphysis pubis to the down point on the sacral promontory. ●It is 12 cm

➢Transverse Diameter(13 cm)

It is the distance between the two far ther points on the pelvic brin over the iliopectineal lines.

➢Oblique Diameter(12cm)

It starts from the sacroiliac joint to the opposite iliopubic eminence.

CAVITY

The cavity extends from the brim above to the outline below. The shape is almost rounded Anterior border: symphysis pubis Posterior border: sacral hollow Lateral border: soft tissue

➥Diameter of cavity:

Anteroposterior diameter - From the midpoint of the surface of the pubic symphysis to the junction of the 2nd and 3rd sacral vertebra. All diameters - As there are other organs, tissue and mass present in the cavity, it is very difficult to measure other diameters. So all the diameters of the cavity are considered as 12 cm.

OUTLET

This outlet has greater practical significance because it includes the narrow pelvic strait through which the fetus must pass. It is diamond-shaped.

➥Diameter of outlet:

    Obstetrical Outlet:

Anteroposterior - lower border of the symphysis pubis to tip of sacrum -11 cm Transverse (bispinous) - between two ischial spines -10.5 cm.

    Anatomical Outlet:

Anteroposterior - lower border of ps to tip of coccyx -13 cm

Transverse (bituberous) - between 2 ischial tuberosity-11 cm.

Diameter Of Female Pelvis

REFERENCE: DC Dutta’s Textbook of OBSTETRICS