The effect of a levonorgestrel-releasing intrauterine system on uterine artery blood flow, hormone concentrations and ovarian cyst formation in fertile women.
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.
Järvelä
I
I
Department of Obstetrics and Gynaecology, Oulu University Hospital, Finland.
Tekay
A
A
Jouppila
P
P
D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects*; D004343:Drug Implants / Q000009:adverse effects; D005260:Female; D006801:Humans; D007434:Intrauterine Devices; D016912:Levonorgestrel / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D010048:Ovarian Cysts / Q000209:etiology*; D011374:Progesterone / Q000378:metabolism*; D012039:Regional Blood Flow / Q000187:drug effects; D014599:Uterus / Q000098:blood supply* / Q000187:drug effects* / Q000378:metabolism
D003271:Contraceptive Agents, Female; D004343:Drug Implants; D011374:Progesterone; D016912:Levonorgestrel