"Free levonorgestrel index" (FLI) is a better parameter than plasma level of levonorgestrel for predicting risk of pregnancy during use of subdermal contraceptive implants releasing levonorgestrel.
Olsson
S E
SE
Department of Obstetrics and Gynaecology, University of Uppsala, Sweden.
Odlind
V
V
D003271:Contraceptive Agents, Female / Q000097:blood*; D004343:Drug Implants; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D016912:Levonorgestrel; D009644:Norgestrel / Q000008:administration & dosage / Q000097:blood*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012307:Risk Factors
D003271:Contraceptive Agents, Female; D004343:Drug Implants; D009644:Norgestrel; D016912:Levonorgestrel