How to detect GPIO interrupt source from deep sleep


in my application I have setup the nRF52 to wake-up from deep sleep if a low value is detected on either of two GPIOs (4 and 5). What I'm trying to achieve, is to be able to detect upon wakeup which of the two has caused the interrupt. The issue is that it can be a very short pulse that appears on the GPIOs and causes the interrupt, such that when the device has booted again the signal has gone again to a non-interrupt state, therefore making it impossible (?) to know which GPIO caused the wakeup. Is there a good way to do it? Does the nRF52 chip has any feature that can help? Otherwise, I guess I'll have to implement externally some kind of latch.