title: Endometrial histology, microvascular density and caliber, and matrix metalloproteinase-3 in users of the Nestorone-releasing contraceptive implant with and without endometrial breakthrough bleeding.
abstract: OBJECTIVE
  This descriptive study evaluated endometrial histology, microvascular density and caliber, and quantification of matrix metalloproteinase (MMP-3) expression in long-term users of the Nestorone (NES)-releasing implant who presented or not endometrial breakthrough bleeding (BTB).
  
  
  METHODS
  Endometrial biopsies were obtained from 32 healthy women with unpredictable BTB. The quantitative analysis was performed only in 20 samples.
  
  
  RESULTS
  The mean duration of use of the implant among the 14 women with BTB was 19.6+/-1.0 months, and the other six women had used the implant for 17.7+/-2.3 months (mean+/-S.E.M.). Histological analysis of the endometrial tissue showed a predominance of progestogenic pattern followed by atrophic and proliferative endometrium in both groups. Mucosal breakdown and glandular pseudostratification were observed in half of the cases. Endometrial vascular density was 73.1+/-10.0 and 57.5+/-24.1 vessels/mm(2), and maximum vessel diameter was 923.3+/-86.0 and 1038.0+/-404 microm (mean+/-S.E.M.) in the group with and without BTB, respectively, without significance, and the rate of cells expressing MMP-3x1000 counted stromal cells was 155.8+/-24.8 and 127.0+/-19.0 (mean+/-S.E.M.) in both groups, respectively, without significance.
  
  
  CONCLUSIONS
  This study provides information about some endometrial aspects of women using NES in contraceptive implants. In addition, the endometrium was similar during long-term use of NES-releasing contraceptive implants in women with and without endometrial bleeding.
authors.affiliation: Department of Obstetrics and Gynecology, Human Reproduction Unit, School of Medicine, Universidade Estadual de Campinas (UNICAMP), Campinas 13084-971, SP, Brazil.
authors.forename: Marilia
authors.initials: M
authors.lastname: Oliveira-Ribeiro
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Petta
authors.forename: Liliana A L
authors.initials: LA
authors.lastname: De Angelo Andrade
authors.forename: Margarete M
authors.initials: MM
authors.lastname: Hidalgo
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pellogia
authors.forename: Luis
authors.initials: L
authors.lastname: Bahamondes
mesh_terms: D000328:Adult; D001706:Biopsy; D003271:Contraceptive Agents, Female / Q000009:adverse effects; D004343:Drug Implants / Q000009:adverse effects; D004717:Endometrium / Q000098:blood supply / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D005260:Female; D006801:Humans; D019278:Matrix Metalloproteinase 3 / Q000032:analysis*; D008796:Metrorrhagia / Q000139:chemically induced; D008833:Microcirculation / Q000187:drug effects; D009653:Norprogesterones / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D003271:Contraceptive Agents, Female; D004343:Drug Implants; D009653:Norprogesterones; C029167:ST 1435; D019278:Matrix Metalloproteinase 3