Safety, efficacy and acceptability of implanon a single rod implantable contraceptive (etonogestrel) in University of Benin Teaching Hospital

Abstract

Objective: The study evaluated the safety, efficacy and acceptability of Implanon (etonogestrel) subdermal implant contraceptive amongst its acceptors.

Study design: This was part of an on going prospective longitudinal study that involved 32 women out of 46 sexually active healthy informed volunteers recruited from our family planning clinic between February and March 2007. All the subjects received the single rod subdermal implant Implanon which contains 68 mg etonogestrel. Data on socio-demographic characteristics, menstrual pattern, haematological indices, weight, blood pressure, side effects and user's satisfaction were collected and analysed. The subjects served as their own control.

Results: The mean age and parity were 33.9 +/- 5.2 years and 3.1 +/- 1.7 respectively. The mean weight was 71.4 +/- 12.0 kg at pre-insertion. At 6 months the weight reduced to a non significant (p < 0.13) mean value of 70.0 +/- 10.5 kg and increased to a non significant (p < 0.88) mean value of 71.5 +/- 11.6 kg at 12 months. The mean systolic and diastolic blood pressures did not show statistical significant changes at 6 months follow up (p < 0.17/0.64). However at 12 months there were significant but within normal reductions (p < 0.003/0.05) in the systolic and diastolic blood pressures. The side effects were menstrual abnormalities. Eighteen (56.3%), 1 (3.1%) and 13 (40.6%) reported reduced, increased and combinations of bleeding patterns respectively. No participant had normal cycle. Other experiences were headache, 4 (12.5%) and reduced libido 3 (9.4%). The mean packed and white blood cell concentrations did not show statistical significant changes at 6 and 12 months follow up. At 12 months there was statistical significant increase (p < 0.04) in the mean +/- SD platelet count (205312.5 +/- 75694.8 per ul) when compared with the pre-insertion mean value (176343.8 +/- 52945.3 per ul). One acceptor had thrombocytopenia without any untoward effect. Two subjects discontinued method on account of menorrhagia and headache. The efficacy and continuation rate were 100% and 93.8% respectively. All the clients received adequate information about the method and most of them were satisfied with it at follow up.

Conclusion: Implanon was an effective, safe and acceptable method of contraception amongst its acceptors. Menstrual abnormalities were the major side effects which most of the subjects found tolerable with adequate counseling. The reduced platelet concentration of the one acceptor would require follow up to ascertain the trend.