Correlation of endocrine profiles with bleeding patterns during use of Nestorone (R) contraceptive implants

The-relationship between ovarian hormones and bleeding patterns during cont inuous progestin contraception was studied in 29 women who used Nestorone(R ) (NES) releasing implants, Oestradiol and progesterone were measured in bl ood samples taken twice a week for 6 consecutive weeks, during months 6, 12 , 18 and 24 of implant use. Retrospectively, the association between hormon al concentrations and bleeding patterns was evaluated. Twenty-four short (l ess than or equal to 24 days), 36 normal (25-35 days), 27 long (36-90 days) and nine episodes of amenorrhoea, as well as 28 periods of prolonged bleed ing, were identified. Short cycles, periods of prolonged bleeding and ameno rrhoea were characterized by low oestradiol concentrations. Bleeding after a normal or long cycle regularly occurred after a rise and fall of oestradi ol or oestradiol and progesterone. The duration of bleeding was directly an d significantly associated with the highest concentration of oestradiol in the previous 15 days in anovulatory cycles. Luteal activity was associated with shorter duration of bleeding. Periods of prolonged bleeding were usual ly initiated with a drop in oestradiol and over half ended with an increase in oestradiol, It was concluded that changes in endogenous hormone have a significant influence over the bleeding pattern during use of NES implants.