Which of the most common and ideal pelvis?
A. Android
B. Gynecoid
C. Platypelloid
D. Anthropoid
Correct Answer: B. Gynecoid
Explanation
The most common and ideal pelvis is the Gynecoid pelvis.
Explanation
The female pelvis is classified into four main types: gynecoid, android, anthropoid, and platypelloid. Among these, the gynecoid pelvis is:
✅ Most common
- Found in about 50% of women
- Considered the typical female pelvis
✅ Ideal for normal vaginal delivery
- Pelvic inlet is round or slightly oval
- Adequate anteroposterior and transverse diameters
- Wide subpubic angle
- Ischial spines are blunt and widely separated
- Pelvic cavity is roomy and well-curved
- Pelvic outlet is wide
🔹 Obstetric significance
- Allows easy engagement, descent, and rotation of the fetal head
- Least likely to cause obstructed labor
- Hence called the most favorable pelvis for childbirth
Summary
Feature Gynecoid Pelvis Frequency Most common Shape of inlet Round / oval Suitability Best for normal delivery
👉 Therefore, the gynecoid pelvis is both the most common and the ideal pelvis.
Other Options Details
These are the four classical types of female pelvis described in obstetrics. Each type has characteristic features and implications for labour and delivery.
A. Android Pelvis
- Resembles the male pelvis
- Pelvic inlet: Heart-shaped or triangular
- Sacrum: Flat and inclined forward
- Ischial spines: Prominent
- Side walls: Convergent
- Pelvic outlet: Narrow
Obstetric significance:
- Unfavourable for normal vaginal delivery
- Increased risk of obstructed labour and operative delivery
B. Gynecoid Pelvis
- Typical female pelvis
- Pelvic inlet: Rounded or transversely oval
- Sacrum: Wide, curved, and well-inclined
- Ischial spines: Blunt and not prominent
- Side walls: Straight
- Pelvic outlet: Wide
Obstetric significance:
- Most common and ideal pelvis for normal vaginal delivery
- Labour usually progresses smoothly
C. Platypelloid Pelvis
- Flattened pelvis
- Pelvic inlet: Transversely oval (flat)
- Anteroposterior diameter: Reduced
- Transverse diameter: Increased
- Sacrum: Flat
- Pelvic outlet: Relatively wide
Obstetric significance:
- Engagement of the fetal head may be delayed
- Vaginal delivery may be difficult but possible
D. Anthropoid Pelvis
- Pelvic inlet: Oval with long anteroposterior diameter
- Transverse diameter: Narrow
- Sacrum: Long and deep
- Ischial spines: Not prominent
- Pelvic outlet: Adequate
Obstetric significance:
- Favourable for vaginal delivery
- Occipito-posterior position of the fetal head is common
Summary Table
Pelvis Type Inlet Shape Suitability for Labour Gynecoid Round Most favourable Anthropoid Oval (AP long) Generally favourable Platypelloid Flat Less favourable Android Heart-shaped Least favourable
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Writer: Vandita Singh, Lucknow (GS India Nursing Group