Thanks for your query.
as you have already got a baby so Copper T can be safe and most effective contraceptive
method, make sure your wife did not have Postpartum infection
or PID in last three to four months.Copper T is effective for about 10 years. Other IUD is Mirena
which unlikely to Copper T contain harmone and is effective for 5 years. Only 1% of failure has been reported with these IUDs.
Usually IUDs like copper T are safe but copper may trigger allergies in some women and may cause unusual heavy vaginal bleeding
and cramps. Rarely it may perforate uterus
Cost is reasonable but can vary depending on product company.
Hope it helps.