Faundes A, Tejada A S, Brache V, Alvarez F
Contraception. 1987 Feb;35(2):189-96. doi: 10.1016/s0010-7824(87)80010-0.
Serum ferritin was measured in 4 groups of long-term users of NORPLANT implants. The users were divided according to their own subjective perception of bleeding: a random sample of 46 one year active users; 30 active users who had increased bleeding; 39 women who had increased bleeding and had the implants removed; 28 active or terminated users who had reduced bleeding. These four groups were compared with a control group of 68 new acceptors of any method at the same clinic who met the criteria for use of NORPLANT. The mean age, parity, years of schooling and family income were similar for the 5 groups. Mean hematocrit for all NORPLANT groups were significantly higher than the control group. About half of the NORPLANT subjects and controls with normal hematocrit had ferritin levels below 11 ng/ml. The proportion of subjects with ferritin less than 11.0 ng/ml were: Group 1) 48%; 2) 63%; 3) 77%; 4) 36% and
57%. Mean iron stores for all NORPLANT users did not differ significantly from those of a demographically similar control group. Significant differences were, however, observed in two subgroups of NORPLANT users. Those women who had increased bleeding and requested implant removal had lower mean ferritin levels and those who perceived decreased bleeding as a result of NORPLANT use had higher ferritin concentration.