Contracted Pelvis: Definition, Causes, Signs, Diagnosis, Complication and Treatment

CONTRACTED PELVIS

---

Definition:

Anatomical Definition:

A contracted pelvis is defined as where essential diameters of one or more planes are shortened by 0.5 cm.

Obstetrical Definition:

Alteration in size and shape of the pelvis to alter the normal mechanism of labor in an average size baby.

Type of Female Pelvis:

Gynecoid (50%)

Android (20%)

Anthropoid (25%)

Platypeelloid (5%)

Causes of Contracted Pelvis / Risk Factors:

➦ Nutritional Deficiency

Nutritional deficiency can increase the risk of a contracted pelvis. Inadequate intake of essential nutrients like calcium, vitamin D, and protein can lead to poor bone development and reduced pelvic growth. This may result in a contracted pelvis.

➦ Environmental factors

Environmental factors like poor nutrition, inadequate prenatal care, limited healthcare access, and cultural practices can increase the risk of contracted pelvis by impairing pelvic bone development.

➦ Disease or Injury

Diseases/injuries like fractures, tumors and other medical conditions increase the risk of the contracted pelvis. Fractures can lead to pelvic deformities reducing birth canal size. Tumors might invade pelvis, affecting pelvic shape.

➦ Developmental Defects

Naegele's Pelvis and Robert's Pelvis are developmental pelvic deformities that increase the risk of contracted pelvis. Naegele's Pelvis is characterized by a flattened pelvic inlet, while Robert's Pelvis features a narrowed mid-pelvis.

Signs of Contracted Pelvis

1. Difficult in labor process or prolonged labor.
2. No fetal head descending
3. Early rupture of membrane
4. Edema of cervix, production of fistulas.
5. Signs of bladder compression.

Diagnosis Contracted Pelvis

1. History Collection Past labor history, fracture or tumor
2. Physical Examination- Gaits, Stature (height less than 150 of a woman)
3. Signs of Rickets • Square Head • Pigeon chest • Bow legs
4. Pelvimetry: Assessment of pelvic diameters.
5. Imaging Test: - X-ray, CT Scan, MRI

Complication Contracted Pelvis

▷ During Pregnancy

• Malpresentation
• Rehtroverted gravid uterus
• Pendulous abdomen

▷ During Labour

• Slow cervical dilatation
• Prolonged labor
• Cord prolapse
• Obstructed labor
• Early rupture of membrane
• PPH

▷ Fetal Complications

• Intracranial hemorrhage
• Asphyxia
• Fracture skull
• Nerve Injury

Degrees of Contracted Pelvis

1. Minor degree: The true conjugate is 9-10m

2. Moderate Degree. The true Conjugate is 8-9cm

3. Severe degree: The true conjugate is 6-8 cm.

4. Extreme degree: The true conjugate is less than 6 cm.

Management of Contracted Pelvis

The management of the contracted pelvis depends upon the degree of disproportion and by the seriousness of the complication.

If the pelvis is contracted minor degree then vaginal delivery is possible but for severe or extreme degree contracted pelvis caesarean section can be the better option.