1 INTRODUCTION  
2 NEAR-INFRARED DATA  
2.1 VMC data  
2.2 Complementary data  
3 MULTI-EPOCH CATALOGUE  
3.1 Constructing the multi-epoch catalogue  
3.2 Correcting for residual magnitude offsets  
4 IDENTIFYING VARIABLE STAR CANDIDATES USING REDUCED 𝛘² ANALYSIS  
5 ANALYSIS OF THE VARIABLE STARS  
5.1 General properties  
5.2 OGLE variable counterparts in the VMC survey  
5.3 Periodicity tests  
6 THE YSO SAMPLE  
6.1 Spitzer source selection  
6.2 VMC massive YSO counterparts  
7 RESULTS AND DISCUSSION  
7.1 Light curve classification  
7.2 Properties of the variable YSOs  
7.3 Long-term variability and colour analysis  
7.4 Comparison with Galactic studies  
8 SUMMARY AND CONCLUSIONS