Two-year follow-up of changes in clinical chemistry in Singaporean Norplant-2 rod acceptors: haemostatic changes.

A longitudinal study of coagulation parameters was carried out on 100 Singaporean acceptors using Norplant-2 rods for contraceptive purposes. At the end of 2 years of use, results from this study show a return of platelet count to preinsertion level while platelet aggregation remained significantly enhanced. Thus the net effect of these two changes on an increased tendency for thrombosis needs further evaluation. The PT and APTT continued to remain persistently shortened during the period of use. There was also a general fall in fibrinogen and most other coagulation factors during the two years of use. Thus, again, the net effect of these two changes on the exposed potential for hypercoagulation at the end of the first year needs further evaluation throughout the five years of Norplant-2 use.