Impact of combination oral contraceptives depot medroxyprogesterone acetate and the levonorgestrel intrauterine system on diffusion of HIV type 1 within cervicovaginal mucus
Awarded 2010
Large Research Grants
Cassing Hammond, MD
Northwestern University

Objectives: Despite data suggesting a relationship between HIV transmission and hormonal contraception, prior studies have only investigated the mechanism of hormonal influence at the level of the vaginal epithelium, neglecting genital mucus. The Levonorgestrel-Intrauterine System (Mirena, LNG-IUS) exerts contraceptive action by thickening cervical mucus. Changes in cervical mucus induced by the LNG-IUS might impact HIV acquisition and transmission. This study compared rates of diffusion of HIV-1 in cervical mucus before and three months following initiation of the LNG-IUS . Methods: Investigators aspirated cervical mucus before and three months following insertion of the LNG-IUS. Mean Square Displacement (MSD) of control nanobeads and fluorescently labeled HIV particles were measured. Investigators examined the relationship between log transformed MSDs and particle type (Bal and beads), time (before and after LNG-IUS), and their interaction using Generalized Estimating Equations (GEEs). Wilcoxon rank sum tests were used to evaluate differences. SAS 9.4 was used. P values < 0.05 were considered statistically significant. Results: 63 patients enrolled in the trial. Screen failures most commonly occurred due to vaginosis and inability to image cervical mucus. There were 27 MSD values from 63 women for Bal and beads before and after Mirena and 10 of each after treatment. When evaluating the log-transformed estimated mean MSD values, Bal MSD was significantly higher than beads prior to treatment, but there was not a difference after treatment (p<0.01 and p=0.16 respectively). Bal MSD was significantly higher before LNG-IUS placement than after (p<0.05). There was not a difference between MSD values before and after treatment for beads (p=0.24). Conclusion: MSD of Bal HIV significantly decreased three months following placement of the LNG-IUS.