A319 Pilot reported unusual thump followed by a momentary pitch down which continued several times. Considering the aircraft had been written up the previous flight for F/CTL ELEV SERVO FAULT DISPLAYED IN FLIGHT LEFT ELEV GREEN HYD SYSTEM and signed off with RESET ELAC 1 AND 2 OPS CK GOOD; the flight crew was concerned the situation might worsen and decided to divert.

Narrative

On climb out with the autopilot engaged; I noticed a slight pitch down on several occasions. We were in light chop so I wasn't overly concerned. Once at cruise altitude in smooth air; I felt a slight bump and noticed the vertical speed show approximately 600-700 FPM descent. The autopilot immediately arrested the decent and maintained altitude. No ECAM message was received. A few minutes later it reoccurred. A minor thump followed by a momentary pitch down. This continued several times and seemed to be increasing but only slightly. Considering the aircraft had been written up the previous flight for 'F/CTL ELEV SERVO FAULT DISPLAYED IN FLIGHT LEFT ELEV GREEN HYD SYSTEM ' and signed off with 'RESET ELAC 1 AND 2 OPS CK GOOD' we were concerned about possibility of the situation becoming worse and decided to divert to ZZZ. I slowed the aircraft to see if that would somehow resolve the issue to no avail. The aircraft continued with the thump and pitch issues at least 15 times during the flight. We landed in ZZZ safely. Captain contacted maintenance and tracking. We received a call and we were treated very well and professionally.Cause - Possibly a quick sign off on the previous flightSuggestion - Possibly more follow up on write ups especially flight control issues