Question
A female presents with primary amenorrhea and absent vagina, the next investigation to be done is :
| A. |
LH / FSH assay
|
| B. |
Chromosomal analysis
|
| C. |
Urianalysis
|
| D. |
Laparoscopy
|
Show Answer
|
Correct Answer » B
Explanation
|
|
- Primary amenorrhea + absent vagina suggests:
- Müllerian agenesis (MRKH syndrome) OR
- Androgen insensitivity syndrome (AIS)
- These two conditions must be differentiated first.
- Chromosomal analysis (karyotyping) is the most important next step.
- It differentiates:
- 46,XX → Müllerian agenesis (normal female genotype)
- 46,XY → Androgen insensitivity syndrome (genetically male)
- This distinction determines further evaluation and management.
Explanation why other options are incorrect
Option A. LH/FSH assay
- Hormonal evaluation is secondary
- Does not distinguish between MRKH and AIS reliably
Option C. Urinalysis
- No role in diagnosis of amenorrhea with absent vagina
Option D. Laparoscopy
- Invasive
- Not first-line
- Done later if needed after initial evaluation
