The Arduino is a 5V device, and your IMU looks like a 3.3V device.
The output from the Arduino I2C bus is 5V.
If the IMU is not 5V tolerant, you may fry it if you don't use a level translator.
If it is 5V tolerant, then you have to make sure to pull up the SDA and SCL pins to 5V to make sure the Arduino can read them as "high." 2.2kOhm resistors between A4/A5 and 5V would solve this.