In general abortions are safe with low complication rates when performed by a gynaecologist in a MOH approved clinic or hospital.
Common complications would include small amount of placental tissue remaining in the uterus (generally in the order of less than 5%). This is usually due to perhaps a small bit stuck in corner of the uterus and it would be unsafe to continue scraping at the area. This usually may pass out on its own or the gynaecologist may suggest some medication to expel it. Rarely it may require a second procedure.
Other complications include uterine or pelvic infection but this is quite rare (less than 1-2%) if done in aseptic manner by a gyne. This is more associated with “illegal back street abortions”.
If a woman has repeated curettages, she is at higher risk of Asherman’s syndrome where scar tissue forms within the uterus causing reduced or absent menstrual flow and sometimes infertility. Often this requires surgery to correct.
Another rare complication is that of uterine perforation where a puncture is made through the uterine wall. This is usually corrected by a laparoscopic procedure to assess for further injury and to stop any associated bleeding.