Hello.Welcome.Injectable iron is safe and can be during pregnancy
.Rate of response with parental iron is not faster than with optimal doses given orally.However stores can be replenished in a shorter time by parentral therapy.Side effects are pain,abscess at the site,flushing,palpitations,headache,joint pains
and sometimes a severe anaphylactic reaction
causing vascular collapse.No problem in future.The cause of iron deficiency
should be identified.Good luck.