Endometrial vascularization in levonorgestrel intrauterine device users; computerized microvessel measurement study

Area of Science:

• Reproductive Medicine
• Gynecology
• Endometrial Physiology

Background:

• The levonorgestrel intrauterine device (LNG-IUS) is a widely used contraceptive method.
• Its mechanism involves local progestin release, affecting the endometrium.
• Understanding LNG-IUS effects on endometrial vascularization is crucial for reproductive health research.

Purpose of the Study:

• To objectively quantify and compare the endometrial vascular bed in women using LNG-IUS versus those with a physiological endometrium.
• To assess the impact of LNG-IUS on endometrial vascular density and vessel morphology.

Main Methods:

• A comparative study involving 25 women using LNG-IUS and 11 normally cycling women (control group).
• Endometrial tissue samples were obtained via suction curettage at the time of LNG-IUS removal.
• Computer-assisted image analysis and immunohistochemistry (CD31 marker) were used to measure vascular parameters.

Main Results:

• LNG-IUS users exhibited a significant decrease in the number of endometrial vessels (60/mm2) compared to controls (124/mm2).
• The mean vessel area was significantly larger in LNG-IUS users (1255 µm2) than in controls (157 µm2).
• Both the reduction in mean vascular density and the increase in mean vessel area were statistically significant (p<.001).

Conclusions:

• Levonorgestrel intrauterine device use leads to a significant remodeling of the endometrial vasculature.
• This vascular remodeling is characterized by decreased vessel density and increased individual vessel size.
• These findings provide objective evidence of LNG-IUS-induced changes in the uterine lining's blood supply.