The effect of a levonorgestrel-releasing intrauterine system on uterine artery blood flow, hormone concentrations and ovarian cyst formation in fertile women

Hum Reprod. 1998 Dec;13(12):3379-83. doi: 10.1093/humrep/13.12.3379.


To determine the effect of long-acting intrauterine progestin on the impedance to blood flow in the uterine arteries, we applied a levonorgestrel-releasing (20 microg/day) intrauterine contraceptive system (LNG-IUS) to the uterine cavity of 27 fertile, regularly menstruating women. Measurements were performed using transvaginal colour Doppler ultrasonography in the mid-luteal phase and on day 1 of menstruation in the absence of the LNG-IUS and 3 months later in its presence. The mean (SD) mid-luteal uterine artery pulsatility index (PI) had risen from a pretreatment level of 2.28 (0.48) to 2.70 (0.67) after 3 months use of the LNG-IUS (P < 0.01), but as regards day 1 of menstruation, no change was observed. The increase in the mean PI (SD) at the mid-luteal phase was present only in subjects with serum levonorgestrel concentrations >200 pg/ml (n = 16) [pretreatment, 2.25 (0.47); with LNG-IUS, 2.83 (0.59), P < 0.001], and absent in those with serum levonorgestrel concentrations <200 pg/ml (n = 10) [pretreatment, 2.31 (0.53); with LNG-IUS, 2.51 (0.79), ns]. Mean progesterone concentrations were lower with the LNG-IUS in place in both groups. We conclude that a levonorgestrel-releasing intrauterine device appears to increase the impedance to blood flow in the uterine arteries during the mid-luteal phase in correlation with serum concentrations of LNG and a concomitant decrease in serum progesterone concentrations.

MeSH terms

  • Adult
  • Contraceptive Agents, Female / administration & dosage
  • Contraceptive Agents, Female / adverse effects*
  • Drug Implants / adverse effects
  • Female
  • Humans
  • Intrauterine Devices
  • Levonorgestrel / administration & dosage
  • Levonorgestrel / adverse effects*
  • Middle Aged
  • Ovarian Cysts / etiology*
  • Progesterone / metabolism*
  • Regional Blood Flow / drug effects
  • Uterus / blood supply*
  • Uterus / drug effects*
  • Uterus / metabolism


  • Contraceptive Agents, Female
  • Drug Implants
  • Progesterone
  • Levonorgestrel